Ultrasound examination of the salivary glands

AUTHORS: Daniel London, Oded Nahlieli

Keywords:

sonography (ultrasound), salivary glands, parotid gland, submandibular gland, sublingual gland, stones, tumor, inflammation

Key points

• The salivary glands are superficial and can therefore be examined in detail using ultrasonography.
• It is important to scan each gland sequentially according to the protocol.
• The salivary glands can be affected by inflammatory, benign and malignant pathology, which can be detected sonographically.
• The salivary glands may have congenital anatomical abnormalities and may contain calculi, which are also detected sonographically.
• The purpose of the article is to gain in-depth knowledge about the structure of healthy glands, available sonography techniques, pathological changes and differential diagnosis of diseases.

Physical basis and equipment

Ultrasound is a high-frequency acoustic wave that uses a frequency outside the normal hearing range (20 Hz-20 kHz). Most head and neck and maxillofacial equipment are tuned to 8 MHz (8 million cycles per second) or higher. This is in contrast to ultrasound diagnostic devices used in general surgery or obstetrics, which typically operate at a frequency of 5-6 MHz, which provides greater tissue penetration but reduces image resolution. Sensors generating frequencies up to 20 MHz and, in the case of ultrasound biometry, up to 50 MHz, are now also used for imaging the salivary glands. This allows very small structures to be distinguished.

The three major salivary glands (parotid gland, submandibular gland and sublingual gland) are paired and are easily accessible due to their superficial location for sonographic diagnosis using high-frequency linear transducers (8-18 MHz).

Nowadays, the use of high-performance ultrasound devices generates a sonographic image like an anatomy book, even using smartphone ultrasound. The resolution and penetration depth of ultrasound depend on the specified frequency. The higher the frequency, the better the resolution, but the penetration is worse. For visualization of the salivary glands, linear probes with a frequency of 7.5 MHz (5.0-13.5 MHz) are most effective. Box 1 shows the scanning sequence.

Under normal conditions, the three major salivary glands have a similar homogeneous intermediate echogenicity with sharp boundaries. Small salivary glands become accessible for sonographic diagnosis only in the presence of pathological changes (for example, enlargement due to a tumor or neoplastic process). Indications for sonographic examination include swelling or increased volume in the area of ​​the salivary glands and pain. Ultrasound examination (Box 2) allows the doctor to clarify the localization, namely: whether the formation is located in the gland, or is simply adjacent to the contour of the salivary gland. This differential diagnosis often cannot be made solely on the basis of clinical examination.

Pathological anatomy

Dystrophic changes in the salivary glands are often combined with a violation of their functions. Protein dystrophies (see Protein dystrophy) are characterized by cloudy swelling of glandular cells (granular dystrophy) and hyalinosis of interstitial tissue (see Hyalinosis). Granular degeneration of glandular cells is observed with sialadenitis (see), cachexia (see), as well as with poisoning with salts of heavy metals (mercury, lead, etc.), released with saliva and damaging glandular cells. Hyalinosis of the interstitial tissue leads to thickening of the interlobular septa; hyaline can be found in the walls of small vessels and in the basement membranes of the terminal (secretory) sections of the veins. With general amyloidosis (see), amyloid is occasionally deposited in the walls of blood vessels and basement membranes. Fatty degeneration of glandular cells (see Fatty degeneration) is observed in infectious diseases (diphtheria, tuberculosis) and chronic cardiovascular diseases. Lipomatosis S. is expressed in the growth between their lobules of adipose tissue (see Lipomatosis). Excessive development of adipose tissue in the thickness of the stomach. occurs in general obesity (see) and senile atrophy of the stomach.

Carbohydrate dystrophies (see) are observed in diabetes mellitus and are characterized by the appearance of inclusions of glycogen (see) in the cytoplasm of glandular cells.

Necrosis S. g. is rare and occurs. arr. with purulent denitis.

Disorders of blood and lymph circulation in the stomach. have no independent significance in the overall pathological picture. They are only local manifestations of general circulatory disorders, occurring in the form of venous hyperemia (see). Arterial hyperemia is observed, as a rule, during local inflammatory processes in the stomach. and in case of disruption of innervation. Hemorrhages in the S. g. are noted in blood diseases, injuries and certain inf. diseases (eg, typhoid and typhus).

An acute nonspecific inflammatory process in the gland—adenitis—occurs as a result of the introduction of pathogens of a viral or bacterial infection that penetrate the gland through the excretory duct, as well as by hematogenous or lymphogenous routes. There is a diffuse form of inflammation of the stomach. and limited (in the form of an abscess). Chronic nonspecific sleeping adenitis can occur primarily and less frequently, as an outcome of acute inflammation of the stomach. With chronic inflammation of the stomach decrease in size and acquire a dense consistency. Microscopically, infiltration of the stroma and parenchyma of the glands with lymphoid elements, atrophy of the terminal (secretory) sections and pronounced stromal sclerosis are noted.

Defeat S. zh. in tuberculosis it manifests itself in the form of a unilateral lesion and occurs secondarily as a result of lympho- and hematogenous dissemination. Development of tuberculosis S. begins with damage to regional lymph nodes of the gland, subsequently its parenchyma and stroma are involved in the process. In S. zh. detect miliary tubercles or small nodules undergoing caseous necrosis. Sometimes there is melting of caseous masses with the formation of a tuberculous abscess, which can cause fistulous tracts. With histol. The study reveals tuberculous tubercles of a normal structure (see Tuberculosis), and when the tissue melts, nonspecific inflammatory changes occur.

Defeat S. zh. It is rare in syphilis. Inflammatory changes are detected only in the secondary and tertiary periods of the disease and can be diffuse or limited in nature. With diffuse inflammatory infiltration (most often in the secondary period) S. It is affected throughout, and abscess formation and necrosis of individual areas of the gland often develop. Limited forms of damage are characterized by sclerosis and atrophy of the stomach. Histologically in the S. g. detect changes corresponding to the picture of specific inflammation in syphilis (see).

Actinomycosis of the salivary glands can develop primarily, as a result of the penetration of actinomycetes into the gland along the ducts, or secondarily, when the inflammatory process spreads from the surrounding salivary glands. soft tissues. Primary actinomycosis (see) proceeds slowly, with periodic exacerbations. In S. zh. a dense, limited infiltrate is revealed, which subsequently spreads to the entire gland with the formation of multiple abscesses. Secondary actinomycosis has less clear symptoms due to the development of a diffuse inflammatory process in the surrounding tissues. Specific inflammatory changes in actinomycosis of S. characterized by the development of granulation tissue with small pustules and pronounced signs of scarring. Druses of actinomycetes are often found in the inflammatory infiltrate, which, when localized in the excretory ducts, can be the basis for the formation of salivary stones.

Of the parasitic diseases of S. zh. Cases of echinococcosis are extremely rare. At the same time, S. are affected secondarily, and macro- and microscopic changes in them are similar to those with damage to other organs (see Echinococcosis).

Hypertrophy of the stomach. is a response to patol. processes occurring in the body. Increase in s. observed in endocrine diseases (eg, diffuse toxic goiter, hypothyroidism), cirrhosis of the liver and usually occurs as a result of reactive proliferation of interstitial tissue, which leads to interstitial sialadenitis. Hypertrophy of interstitial tissue is also observed in Mikulicz syndrome (see Mikulicz syndrome). In physiol. conditions of hypertrophy of the stomach. observed during pregnancy and the postpartum period. Sometimes, after removal of one of the paired glands, vicarious hypertrophy develops on the opposite side.

Atrophy of the s. characterized by a decrease in their size. Atrophic changes are observed when there is a violation of the innervation of the gland, age-related involution, as well as when the outflow of gland secretions is difficult, followed by atrophy of the parenchyma. Histologically, there is a proliferation of connective tissue with thickening of the interlobular septa, a decrease in the size of glandulocytes, and emphasized lobulation of the sternum.

Postmortem changes in S. zh. occur early (after 3-4 hours), which is associated with the self-digesting effect of salivary enzymes. Macroscopically, the glands acquire a reddish tint and soften. With pathohistol. The study reveals destructive changes in glandular cells, while interstitial tissue retains its structure much longer.

Examination methods include, in addition to general methods (questioning, examination, palpation, etc.), such special methods as probing the ducts, sialometry (see Salivation), cytol. examination of secretions, ultrasonic dowsing (see Ultrasound diagnostics), thermovisiography (see Thermography), scanning (see), sialography (see), pantomography (see), pneumosubmandibulography (see), computer tomography (see).

HOW TO SCAN (PROTOCOLS)

Parotid gland

The parotid gland can be easily examined with the patient's head turned to the side and in a hyperextension position. A summary of the scanning procedure is provided in Box 3.

First, the gland is scanned in cross section, starting from the angle of the jaw to a point slightly above the tragus. Then the longitudinal projection is scanned. The ultrasound probe must be adequately applied to the surface of the skin, using a sufficient amount of gel, especially in the area of ​​the angle of the jaw.

Submandibular gland

If the patient's head is moderately extended, the submandibular gland can be examined ultrasonographically without any problems. First of all, along the midline of the neck, the ultrasound sensor moves in the transverse direction from the hyoid bone to the horizontal branch of the mandible. Sometimes both submandibular glands may be visible at the same time. Then, by moving the transducer sideways, parallel to the horizontal ramus of the mandible, a clear image of the corresponding submandibular gland can be obtained. Here it is necessary to ensure good contact of the gel with the sensor on the skin.

Sublingual gland

The sublingual gland examination does not have significant differences in procedure compared to the submandibular gland examination. The transducer is placed on the skin in a transverse plane in the midline just below the mandible, allowing visualization of both sublingual glands. It is important to note that all averaged structures must be within 0.2 mm of each other, and any outliers are carefully assessed and discarded and, if necessary, reanalyzed.

Pathology

Patol, processes in P. zh. similar to those with damage to other salivary glands. On patol, the condition of the gland is indicated by an increase in sublingual folds, painful in acute inflammation, painless in chronic inflammation, dense consistency in tumors and soft consistency in pancreatic cysts.

Damage

P.J. are relatively rare. In case of a gunshot wound, they are usually combined with damage to the bones of the facial skull. In addition, there are cases of damage to the pancreas. disc during the preparation of lower jaw teeth for crowns, during surgery for acute inflammatory processes in the sublingual region, when removing salivary stone (see Sialolithiasis) from the middle or posterior sections of the submandibular duct. Damage to the gland can be diagnosed by examining the wound, in which the glandular tissue can be clearly visible. Patients are bothered by pain when talking or eating. As a result of scarring of the wound, the outflow of secretions from the ducts of the pancreas. may be disrupted, which leads to the appearance of a ranula - a retention cyst (see Cyst).

Diseases

P.J. include reactive-dystrophic processes, acute and chronic inflammation, cysts, tumors (see Salivary glands).

Reactive-dystrophic diseases are usually not an isolated lesion of the pancreas: they develop with systemic damage to the salivary and lacrimal glands - Mikulicz's disease (see Mikulicz syndrome), all excretory glands - Sjögren's syndrome (see Sjögren's syndrome), as well as other autoimmune and endocrine diseases (see Salivary glands). P.J. At the same time, it increases in size, becomes denser, and subsequently a decrease in its function is observed.

Rice. 2. Sublingual area with acute inflammation of the sublingual salivary glands: sublingual folds of uneven thickness (indicated by arrows), the mucous membrane of the sublingual area is swollen. Rice. 3. Sublingual area with chronic inflammation of the sublingual salivary glands: 1 - tongue, 2 - frenulum of the tongue, 3 - thickened, raised sublingual folds, 4 - tuberous surface of the right sublingual gland.

Inflammation of the pancreas. can be acute or chronic. The cause of acute infection can be mumps viruses with an atypical course (see Epidemic mumps), influenza (see), etc. The disease begins acutely and is accompanied by an increase in body temperature. The gland is enlarged in size, sharply compacted on palpation, and painful. The sublingual folds are thickened, the oral mucosa is swollen (Fig. 2). These phenomena persist for 4-5 days, then the infiltrate slowly resolves and the condition returns to normal. On the 2-3rd day of the disease, an abscess may develop. Treatment is conservative, in case of an abscess - surgical. Chron, inflammation of the pancreas. is observed relatively rarely, is usually bilateral and is combined with damage to the parotid or submandibular salivary glands (see Parotid gland, Submandibular gland). Clinically manifested by swelling of the pancreas. If left untreated, the gland slowly enlarges, thickens, and becomes lumpy (Fig. 3). Pain appears only when the process worsens. Treatment includes general measures aimed at increasing the body's resistance; novocaine blockade is applied locally. In addition, treatment of concomitant diseases is necessary.

The most common patol, process in P. g. is a retention cyst, which occurs when the outflow of secretions from the pancreas is disrupted. The shell of the cyst consists of connective tissue rich in blood vessels, the bundles penetrate into the connective tissue layers of the lobules of the pancreas. In the peripheral parts of the cyst shell there are elongated cells such as fibroblasts; very rarely one or two rows of cubic or multirow cylindrical epithelium cells are found on the inner surface of the cyst shell. The first wedge, a symptom of a cyst, is the appearance of swelling in the sublingual area (painless, soft or elastic consistency), the edges, slowly increasing, can spread to the submandibular area. When the mucous membrane of the floor of the mouth in the sublingual region becomes thinner, spontaneous opening of the cyst and its emptying may occur. In this case, it decreases in size or is not detected at all, but after a certain time (weeks, months) it reappears and increases. Treatment of the cyst is surgical: a cystotomy is performed (opening the cyst and emptying) or the cyst is removed along with the pancreas.

ANATOMY

Update your anatomy knowledge

The parotid glands consist of a prismatic body and two elongated parts: the anterior part is located on the deep part of the masseter muscle, and the deeper elongated parts, which reach the lateral wall of the pharynx, pass between the prestyloid muscles and the stylomandibular ligament.

The submandibular glands are located in the submandibular space under the floor of the mouth and have a mesial extension called the “hook.” The excretory Wharton's duct arises from this expansion, which is located at the base of the frenulum of the tongue and opens into the sublingual papilla.

The sublingual glands are a group of glands located in the sublingual space, which are limited by the recess of the tongue, the floor of the mouth and the geniohyoid muscle.

Glands of external, internal and mixed secretion

The normal functioning of the human body depends on regulatory systems. These include human glandular systems.

The glands make all organs and tissues work with the help of enzymes and hormones. Thus the organism exists as a single whole.

Gland

- This is an organ that produces any substance necessary for the body.

These substances can be released as secretions onto the surface of the body or into the body cavity. And also as a hormone directly into the blood.

· Exocrine glands are called exogenous.

· Endocrine glands are endogenous.

The prefix exo- from the Greek word (exo) means “outside, outside”;

Prefix endo - (endon) - inside.

Exocrine glands

– exogenous. They produce substances (“secret”) and release them into the external environment of the body or into its cavity.

Sweat glands

.

These are skin glands that secrete secretions in the form of sweat onto the surface of the body.

Sweat

is an aqueous solution of salts and organic substances.

As a result of profuse sweating in the hot season, the body cools down.

As well as the removal of metabolic products harmful to it, toxic substances that could enter the body along with food or medicine.

Sweat glands are distributed over almost the entire surface of the body. A large number of them are located on the palms, soles, and also on the forehead.

Mammary gland

- These are modified sweat glands. Both women and men have them. They are similar in structure, but differ only in the degree of development.

The glands consist of separate lobes. They form branching tubes called milk ducts. At the end they have extensions in the form of lobules.

Each lobule contains mammary glands. They form a secret

- milk.

The lobes are separated by layers of loose connective and adipose tissue.

The peculiarity of the mammary gland is that it functions only during the period of feeding the baby.

Sebaceous glands.

They are located in human skin and consist of branched terminal sections in the form of a sac and an excretory duct.

The pouch itself is filled with secretory cells with fat vacuoles.

During secretion, these cells are completely destroyed and all their contents turn into secretion, that is, sebum.

The sebaceous glands have excretory ducts that empty into the hair canal.

They are found in almost all parts of the body. Absent on the palms and soles.

The next exocrine glands
are the lacrimal glands.
They consist of several groups of small alveolar-tubular glands, which are located in the frontal bone. Glands have excretory ducts

which open into
the lacrimal sac
. Clear tear fluid is released from it.

Ninety-eight percent of tears consist of water, and the remaining two percent are protein, urea, mineral salts, and the enzyme lysozyme.

.

Functions of the lacrimal gland secretion

, that is, tears.

They clean the surface of the eye from dust, lint and other contaminants.

Tears regularly wash the eyes. At the same time, they protect it from drying out.

Tears are involved in the nutrition of the cornea. They also protect against harmful microorganisms;

The salivary glands are also classified as exocrine glands.

which are located in the oral cavity. Their excretory ducts exit into the body cavity.

In humans, in addition to the small salivary glands, which are located in the mucous membrane of the tongue, palate, cheeks and lips, there are three more pairs of large salivary glands: the parotid, submandibular and sublingual.

The glands secrete a secretion called saliva

.

It is a colorless liquid that mainly consists of water and inorganic substances.

Saliva also contains the protein mucin, which gives saliva mucous properties. It is necessary for the formation of a food bolus, which is then easily swallowed.

Saliva contains the enzyme lysozyme, which kills bacteria.

A person produces approximately 1.5 liters of saliva per day.

Stomach glands

also classified as exocrine glands.

As you know, the gastric mucosa has folds, due to which the digestible surface area increases.

The epithelium of the stomach contains gastric pits, which are represented by the glands of the stomach.

They secrete gastric juice, which contains hydrochloric acid and digestive enzymes.

Intestinal glands.

The mucous membrane of the small intestine secretes juice. It contains enzymes, amino acids, urea, white blood cells and mucus.

Enzymes are necessary to break down incoming particles into food molecules. Mucus is necessary to protect the mucous membrane and also for the attachment of enzymes.

Endocrine glands.

Pituitary

─ brain appendage in the form of a round formation, which is located on the lower surface of the brain.

Pituitary

- This is the main endocrine gland. The activity of other glands depends on its work.

It consists of 2 parts of glands, which are combined in one organ.

The first gland, the anterior lobe, produces hormones that regulate the functioning of other glands.

The second gland - the posterior lobe of the pituitary gland and the intermediate part consists of nerve cells. Hypothalamic hormones accumulate here.

We will look at hormones and their effects on the human body in more detail in the next lesson.

.

Another endocrine gland is the pineal gland

─ The pineal gland is grayish-red in color, which is located in the center of the brain. Its shape resembles a pine cone, which is why it is called that.

The secretory function of this gland depends on illumination.

The pineal gland regulates the biological rhythms of the body (diurnal, seasonal and others).

It also inhibits the functioning of the pituitary gland. Regulates body growth and sexual development.

gland also belongs to the endocrine glands .

It is located in the neck and consists of two lobes.

Thyroid hormones are involved in:

· In the regulation of metabolism,

· In the growth of individual cells,

· In the maturation of tissues and organs.

· In the metabolism of proteins, fats and carbohydrates.

Thyroid hormones contain iodine. Therefore, the thyroid gland accumulates it. This element is necessary for her health and well-being.

The body requires only 0.3 mg of iodine per day. Pay attention to foods that contain iodine.

In the area of ​​the thyroid gland there are four more small parathyroid glands.

Their number can vary among different people from two to eight. The typical number is 4 glands.

They produce a hormone that controls calcium levels in the body.

Adrenal glands

, also classified as endocrine glands.

They are located above the right and left kidneys. The adrenal glands are composed of two structures—the cortex and the medulla.

The right adrenal gland is triangular in shape, and the left is crescent-shaped.

The adrenal glands produce large amounts of hormones. They regulate the body’s metabolism and also adapt it to unfavorable conditions.

One of the hormones that you all know is adrenaline. Its production increases sharply during stressful conditions, a sense of danger, anxiety, fear, and shock.

Exocrine glands

secrete secretions onto the surface of the body or into the body cavity.
The endocrine glands
secrete the hormone directly into the blood.

Also intermediate glands

mixed secretion. They simultaneously release hormones and substances such as enzymes and digestive juices into both the blood and the body cavity.

These include the gonads, the testes
in men
, and
the ovaries in women
.

These glands secrete germ cells, sperm in men and eggs in women. Due to this, external secretion occurs.

They also release sex hormones into the blood. This is how internal secretion occurs. In men, the predominant hormones are androgens, and in women, estrogens, which determine gender, puberty and behavior.

Another gland of mixed secretion is the liver

.

It is the largest gland in humans. It is located on the right side of the abdominal cavity under the diaphragm.

The liver consists of lobes

,
right and
left . Each of which consists of a thousand prismatic slices.

The liver produces bile. Which enters the gallbladder. Its ducts open into the duodenum.

The liver is the most important blood depot. A quarter of the body’s total blood is retained in it.

It controls the constancy of the internal environment of the body - homeostasis. Vitamin A is formed and accumulated in it.

The liver removes toxins from the body, such as alcohol. Maintains constant body temperature.

In addition, the liver is capable of regeneration, that is, the restoration of lost parts.

Another gland of mixed secretion is the pancreas.

It is the second largest after the liver.

It is represented by a lobular formation, which is located in the abdominal cavity behind the stomach. It is closely adjacent to the duodenum.

The pancreas has an exocrine

and
endocrine parts
.

The first opens its ducts into the duodenum and secretes pancreatic juice, which contains enzymes necessary for digestion. This is how external secretion occurs.

The endocrine second part of the pancreas consists of Langerhans cells. They carry out internal secretion, that is, they release the hormone insulin into the blood, which is involved in carbohydrate metabolism.

Thymus gland (thymus).

The thymus gland got its name due to its characteristic shape, reminiscent of a trident fork or even the staff of Poseidon. The thymus gland has another name - thymus, which translated from Greek means “life force”.

The thymus is located in the upper part of the chest. A gland consisting of two lobes, the lower parts of which are wide and the upper parts are narrow.

Cells
called lymphocytes in the thymus , which recognize and destroy harmful substances to the body. Thus, they are responsible for the immune function of the body.

Exocrine glands:

Endocrine glands:

Mixed secretion glands:

NORMAL ULTRASONIC ANATOMY

Parotid glands

The parotid glands, which are the largest of the salivary glands, are enclosed in a separate fascia, which penetrates the glands, forming various lobules. In cross-section, the parotid gland is a sharply defined, homogeneous organ with intermediate echogenicity (Fig. 1).

Rice. 1. Normal parotid gland.

The gland can be clearly distinguished from subcutaneous adipose tissue. The anterior part of the gland sits on the masticatory muscle and can be differentiated from the buccal adipose tissue, which has lower echogenicity, by contraction and relaxation of the masticatory muscles. The posterior part of the gland is located in the retromandibular fossa and is clearly delimited anteriorly by the ascending ramus of the mandible, and posteriorly by the sternocleidomastoid muscle and the mastoid process. Mediocaudal to the inferior pole of the parotid gland, the posterior belly of the digastric muscle and the internal carotid artery can be distinguished. It is important to remember that a small portion of the parotid gland may be hidden by the acoustic shadow of the mandible.

In and around the gland, the internal jugular vein and the retromandibular vein can be found, which are located in the glandular parenchyma and can be visualized, especially in the longitudinal projection. In transverse views, distal to the retromandibular vein, the styloid process is projected onto the glandular parenchyma, which should not be confused with sialolithiasis. The facial nerve is usually not visible. However, with the use of modern high-resolution transducers, it is sometimes possible to obtain a sonographic image of the main outflow canal.

Submandibular gland

The submandibular gland extends cranial to the mandible and the geniohyoid muscle and has a close connection with the anterior belly of the digastric muscle. The submandibular gland forms an arch around the posterior border of the geniohyoid muscle and often reaches ventromedial to the submandibular gland. Echogenic structures with an element of acoustic shadowing are often projected in the area of ​​the gate of the submandibular gland. In this area, it is necessary to carry out differential diagnosis between the elements of the hyoid bone and the sialoliths of the submandibular gland, which may have comparable characteristics on imaging [2,7]. Sonographic imaging characteristics of the submandibular gland include an intermediate echogenic structure with a regular echo pattern corresponding to the echo pattern of the parotid gland parenchyma (Fig. 2).

Rice. 2. Normal submandibular gland.

In and around the gland, the facial artery and facial vein, which pass through the gland, are easily distinguished sonographically. The path of the efferent duct can sometimes be visualized using high-resolution ultrasound probes, even in the absence of duct obstruction. If we are talking about differentiation of the elements of the hyoid bone, then during swallowing movements its displacements are observed.

Sublingual gland

Visualization of the sublingual gland can sometimes be problematic. The sublingual gland is located under the mucous membrane in the oral cavity, lower in the projection of the tip of the tongue, next to the frenulum of the tongue. The dorsal part of the glands often touches the surface of the submandibular gland.

The gland is bounded ventrally and medially by the geniohyoid and genioglossus muscles, and caudally by the mandible. Short excretory ducts usually cannot be visualized. Accumulation of saliva may be found in and around the sublingual gland, which forms the ranula (Figure 3).

Rice. 3. Sublingual ranula.

Histology

The salivary glands are branched glands consisting of terminal, or secretory, sections and excretory ducts. Each gland is covered with a connective tissue capsule with layers of connective tissue extending from it into the organ, into which blood vessels and nerves pass. These layers divide the gland into lobes and segments, the basis of which is formed by the branches of the small excretory (intralobular) duct, passing into the terminal (secretory) sections. Terminal sections of the s. consist of glandular, secretory cells (glandulocytes) and myoepithelial cells (myoepithelial cells) located outside them. Secretion is formed in glandulocytes. According to the nature of the secretion, they distinguish between protein or serous (parotid gland and Ebner's glands), mucous (for example, palatine glands) and mixed (submandibular, sublingual, buccal, anterior lingual, labial) glands. According to the mechanism of secretion secretion, the salivary glands belong to the merocrine glands (see Glands).

Glandulocytes have a conical shape with a pointed apex and an expanded base. Electron microscopic studies (see Electron microscopy) have shown that on the lateral and basal surfaces of glandulocytes, the plasmalemma forms protrusions, folds and invaginations into the cytoplasm. The lateral surfaces have desmosomes (see) and end plates that provide communication between cells. Microvilli are detected at the apical edges, the number of which increases with increasing secretory activity of the gland. The cytoplasm contains a well-developed endoplasmic reticulum (see), ribosomes (see) and the Golgi complex (see Golgi complex).

The terminal sections of the protein (serous) veins. formed by conical or pyramidal-shaped glandulocytes with basophilic cytoplasm and rounded nuclei - the so-called. serocytes (serocytus). Between the serocytes there are thin intercellular secretory tubules that do not have their own walls, which are a continuation of the cavity of the terminal sections.

The terminal sections of the mucous membranes of the S. g. formed by glandulocytes that have a very light, poorly stained cytoplasm with numerous vacuoles and a dark nucleus - the so-called. mucocytes (mucocytus. The secretion in mucocytes is formed in the form of mucinogen granules, which merge into a large drop of mucus occupying the apical part of the cell, while the nuclei are shifted to the base of the cell and flattened.

Rice. 2. Schematic representation of the mixed salivary gland: 1 - protein end sections; 2 - mixed end section; 3 - crescent of protein secretory cells (serous crescent); 4 - mucous terminal section; 5 - intercalary duct; 6 - striated duct.

In mixed glands, along with purely protein end sections, there are mixed sections, which include both mucous and protein cells. In this case, the central part of the mixed section is occupied by large light mucocytes, and darker serocytes lie along the periphery of the terminal section in the form of a crescent - the so-called. serous crescent, or Januzzi's crescent - semilima serosa (Fig. 2).

Myoepithelial cells (myoepithelial cells) are located on the basement membrane of the stomach. outwards from the glandulocytes, enveloping them with their cytoplasmic processes, the contraction of which promotes the removal of secretions from the end sections and its movement along the ducts. The terminal sections pass into intercalary ducts (ductus intercalati), lined with low cubic or squamous epithelium. They are well developed in the parotid gland, shorter in the submandibular gland and almost completely absent in the sublingual gland. Intercalated ducts pass into striated ducts (ductus striati), or Pfluger tubes, lined with high cubic epithelium, the cytoplasm of which has a characteristic striation. Electron microscopic examination reveals two types of cells here: dark and light (more numerous). The striated ducts are credited with the functions of removing secretions and participating in the processes of its concentration. There is evidence that the cells of the striated ducts take part in the production of hormone-like substances, in particular insulin-like protein. There are no striated ducts in the mucous glands. Intralobular excretory ducts continue into interlobular ducts, lined with double-row epithelium, which, merging, form a common excretory duct, lined in the terminal section with stratified squamous epithelium.

Blood supply of the s. carry out the branches of the external carotid arteries (see), blood flows into the system of the external and internal jugular veins (see). A feature of the circulatory system of the stomach. is the presence of numerous arteriovenular and arteriovenous anastomoses, through which blood from the arteries and arterioles enters the veins and venules, bypassing the capillary bed, which contributes to the redistribution of blood in the gland.

Lymph flows into the chin, submandibular and deep cervical lymph. nodes.

Parasympathetic innervation is carried out by the upper salivary nucleus of the facial and lower salivary nucleus of the glossopharyngeal nerves, sympathetic innervation by the external carotid plexus, in the formation of which the branches of the upper cervical ganglion of the sympathetic trunk take part.

PATHOLOGICAL RESULTS

Box 4 contains a short list of variants of salivary gland pathology.

Acute sialadenitis

Since we have to deal with paired organs, it is important to compare both glands in one picture. Characteristic findings are explained by inflammatory edema and an increase in fluid content in the parenchyma, which is transformed during inflammation. Typically we see the following:

• Diffuse expansion of the entire affected gland.
• The organ can be clearly demarcated from adjacent structures.
• The structure of the parenchyma appears loose, heterogeneous, coarsely textured and more hypoechoic.
• Limited hypoechoic formations can be detected as a concomitant inflammatory reaction of the intraglandular lymph nodes.
• Zones of liquefaction (as signs of abscess formation) are visualized as hypoechoic with a hyperechoic surrounding wall and pronounced distal signal enhancement.
• Coarsely structured hyperechoic echoes at the center of such liquefaction lesions may correspond to areas of necrotic tissue.

Chronic sialadenitis

Sonographic imaging is highly dependent on the duration and degree of inflammation of the glandular parenchyma. As in the case of acute sialadenitis, a conclusive differential diagnosis between the various pathogenic forms of chronic sialadenitis cannot be made using sonography alone. Typically we see the following:

• A clear increase in the unevenness of the echo texture.
• The internal structure has a heterogeneous pattern, most likely due to fibrotic changes in the parenchyma.
• Small cystic echo lesions are formed, which correspond to limited ductal ectasia (Fig. 4).
• Sometimes stones within the gland are identified as echogenic structures with a distal acoustic shadow.

Rice. 4. (A) Chronic sialadenitis of the parotid gland. (B) Sialocele of the parotid gland. (C) Dilatation of Stenson's duct (arrows).

Differential diagnosis is important in the following situations:

1. Patients suffering from Gougerot-Sjögren syndrome have sonographic signs of enlarged, heterogeneously structured, hypoechoic salivary glands. Numerous limited hypoechoic formations are found inside the parenchyma, which may be associated with cystic dilatation of the ducts, on the one hand, or with enlargement of intraglandular lymph nodes, on the other hand. Sonographically, the structure of the salivary glands looks like a “cloud”.
2. Sialadenitis of epithelioid cells (Heerford syndrome) is sonographically characterized by a rich echo pattern interrupted by numerous enlarged lymph nodes that appear as hypoechoic masses.
3. Kütner's tumor of the submandibular gland is visualized as a formation with an indistinct echo signal in a certain part of the submandibular gland, which is easily mistaken for an adenoma.
4. Ultrasound helps detect changes after radiation therapy. The echohomogeneous pattern disappears after irradiation, with a more hypoechoic and sometimes irregular pattern being a sign of loss of function.
5. Other secondary pathological changes (edema, infections and soft tissue tumors) around the salivary glands are easily distinguished from primary salivary gland pathology.

Parotid abscess

The evolution of the inflammatory process is characterized by a hypo-, anechoic lesion with irregular edges. Typically we see the following:

• Hypo-, anechoic lesion with irregular edges.
• Peripheral hypervascularization, which is determined by color Doppler scanning.
• In the case of partial necrotic changes, lymph nodes with anechoic areas of necrosis are identified.
• In the case of fistula formation, a fistula is defined that reaches the skin surrounded by edematous tissue.

An important initial sign of an abscess is the appearance of vessels with a linear and fairly regular direction, which subsequently changes to a more irregular one, and is characterized by numerous anastomoses, which can be determined by an increase in the intensity of the color Doppler signal. In abscesses, the color Doppler signal has a peripheral structure because in this case the vessels are intertwined along the periphery of the abscess.

Enlarged lymph nodes

Lymph nodes may be found inside the parotid gland. However, only around the submandibular gland, due to the characteristics of embryological development. In the parotid gland, a group of small lymph nodes (3-5 mm) is located along the retromandibular vein. These lymph nodes carry out lymph drainage from the Eustachian tube, external auditory canal and deep areas of the face. Intraglandular and extraglandular lymph nodes normally do not exceed 9 mm in diameter.

Ultrasound imaging of otherwise unremarkable glandular parenchyma may reveal predominantly multiple hypoechoic lesions that often lack any distal signal enhancement. Sonographically, as a rule, it is impossible to obtain reliable signs that would allow a definitive differential diagnosis between benign and malignant enlarged lymph nodes.

Reliable differential diagnosis between reactive lymphadenitis (Fig. 5), non-Hodgkin's lymphoma (Fig. 6), MALT lymphoma, or intraglandular metastatic spread is not possible on the basis of sonographic findings alone.

Rice. 5. Pathological lymph node.

Rice. 6. Primary lymphoma of the parotid gland.

Clinical signs, number, location, and sometimes texture of nodes can lead to diagnosis, but do not replace histological analysis. As with enlarged lymph nodes of the neck, some authors mention the so-called “hilus” (gate) as a sign of reactive lymphadenitis.

Cystic tumors

Congenital or acquired salivary gland cysts are usually filled with clear fluid. We usually see an echo-negative tumor with clear borders and distal signal enhancement (Fig. 7).

Rice. 7. Salivary gland cyst (arrows indicate parotid gland, arrowheads indicate cyst).

It is important to note that if cystic tumors are detected sonographically in both parotid glands, and if there is a relevant medical history, then lymphoepithelial cysts caused by HIV infection should be suspected.

Sialolithiasis

Although the sign of a distal acoustic shadow is usually detected, the signal reflection can sometimes be unclear or insufficient. This phenomenon is the result of a reflected ultrasonic component that does not reach the transducer but is scattered out of the image plane. Typically, we see an echo-opaque object with a clear sign of a distal acoustic shadow (Fig. 8) and dilatation of the excretory ducts.

Fig.8. Intraglandular sialolithiasis of the submandibular gland.

Parotid duct stones contain organic components and are visualized with great effort. Sometimes only a distinct echo-opaque object without a distal acoustic shadow may be detected. However, in many of these cases, dilatation of the efferent ducts of the salivary glands can be considered as another indirect sign of the development of sialolithiasis, if the stone cannot be clearly identified. However, dilation of the duct can also be caused by scar changes in the connective tissue (for example, the situation after an inadequately performed incision of the duct or after acute inflammation). Stones with a diameter of 1.5 to 2 mm or more, located in the area of ​​the large salivary glands, can be reliably detected during sonography.

It is important to note that the precise determination of the position of sialoliths (intraglandular, extraglandular and intraductal) is of great importance. Differential diagnosis is important both in the presence of air inside the ducts and in the case of pneumoparotitis, foreign bodies, angiolithiasis and calcified lymph nodes or arteriovenous malformations (Fig. 9).

Rice. 9. Arteriovenous malformation of the salivary glands.

Remember, because of its limited sensitivity and limited negative predictive value, sonography does not reliably exclude small salivary gland calculi. Further diagnostic studies are needed to identify stones in patients with normal sonographic findings and suspected lithiasis.

Sialadenosis (sialosis)

All large salivary glands can be simultaneously affected by sialoadenosis. Sialadenosis is a non-inflammatory condition characterized by bilateral enlargement of the salivary glands, most commonly the parotid glands. Usually we see that the glands look indistinctly enlarged, are difficult to differentiate from surrounding structures, their echo structure looks homogeneously hyperechoic, and with sialoadenosis tumor-like lesions are not detected. In some cases, the parotid gland is so enlarged that ultrasound requires a low-frequency transducer to evaluate the deep part.

Benign epithelial tumors of the salivary glands

A well-defined boundary between the surrounding salivary gland tissue and the tumor itself is a characteristic feature of a benign salivary gland tumor. Because ultrasound is unable to visualize nerves, the relationship of parotid tumors to the facial nerve cannot be reliably determined.

Pleomorphic adenomas have a homogeneous/hypoechoic texture. However, sometimes heterogeneous structures with hard and cystic inclusions may be noticeable. In these cases, a characteristic feature is distal signal enhancement (Fig. 10).

Rice. 10. Pleomorphic adenoma of the parotid gland.

Monomorphic adenomas (adenolymphomas) may also appear sonographically homogeneous and hypoechoic, as is the case with pleomorphic adenomas. If the proportion of cystic structures is high, adenolymphoma may also present completely without echo with extensive distal enhancement. Occasionally, septae may be identified within the tumor.

The remaining less common types of benign salivary gland tumors (eg, basal cell adenomas, oncocytomas, lymphoepithelial lesions) also have similar nonspecific sonomorphological features.

Definitive sonographic identification and differential diagnosis between different types of benign salivary gland tumors is currently impossible, although significant cystic portions in the mass tend to indicate adenolymphoma, and the absence of cystic areas indicates pleomorphic adenoma. To a certain extent, parotid tumors can be classified as either the "superficial" or "deep" part of the gland.

Benign nonepithelial tumors of the salivary glands

Lymphangiomas and hemangiomas (Fig. 11 and 12) have similar sonomorphological characteristics, which makes differential diagnosis between them impossible.

Rice. 11. Intraglandular lymphangioma.

Rice. 12. Submandibular hemangioma.

During the study, loosely connected alveolar structural components, consisting partly of hypoechoic and hypergeogenic areas, can be detected. Sonographic examination allows us to assess the depth of penetration and spread of this tumor into the corresponding salivary gland and into the area of ​​surrounding soft tissue.

Intraglandular and extraglandular lipomas (Fig. 13) appear as sharply demarcated, ovoid formations, with a hypoechoic and homogeneous signal reflection pattern.

Rice. 13. Well-defined lipoma.

Lipoma has a more characteristic hypoechoic reflection pattern than the rest of the salivary gland parenchyma, but its echo texture is more hyperechoic than other types of intraglandular tumors, and it also has a linear hyperechoic feathery texture.

Malignant tumors of the salivary glands

We typically see a fuzzy edge and a patchy echo texture. It is possible to describe the relationship between invasive tumor growth and surrounding tissue. It is impossible to detect involvement of the facial nerve in the malignant process. The most common malignant tumors of the salivary glands are mucoepidermoid carcinoma, adenoid cystic carcinoma, carcinoma arising in pleomorphic adenoma, and distant metastases (Fig. 14).

Rice. 14. Metastatic melanoma in the parotid gland (arrows indicate parotid glands, arrowheads indicate metastases).

Indications for sonographic examination are sometimes absent, since at the preoperative stage it is impossible to identify with complete certainty the benign or malignant nature of tumor development. If a malignant process is suspected, ultrasound-guided fine-needle aspiration biopsy can be a useful tool to more accurately classify the tumor at a preoperative stage.

It is important to note that if tumor margins cannot be accurately imaged by sonographic examination, especially when the tumor extends to osseous or deep structures, the patient's diagnostic imaging should be extended in any case to computed tomography and/or magnetic resonance imaging.

Gougerot-Sjögren syndrome

Gougerot-Sjögren syndrome occurs when lymphocytes invade and destroy the exocrine gland. It is the second most common autoimmune syndrome after rheumatoid arthritis, affecting the salivary glands in 40-80% of cases. This results in a higher incidence of parotid lymphomas and salivary stone disease. Typically we see the following:

• At an early stage, sonography is normal.
• Later, the glands become enlarged and large-scale structural damage occurs.
• The gland is heterogeneous.
• At a later stage, sonographic examination reveals sialoectasia and marked hypervascularization on color Doppler ultrasonography of the salivary glands.

Rice. 15. Minimally invasive procedures under ultrasound guidance.

Rice. 16. Therapeutic intraglandular injection of Botox.

Color Doppler ultrasonography of the salivary glands

The standard B-scan is a well-established tool for diagnosing salivary gland diseases. For tumors located in the salivary glands, there is increasing interest in non-invasive collection of clinical information such as growth and invasiveness, as well as making an accurate diagnosis before surgery. Before the benefits of sophisticated ultrasonography became available, standard testing was performed by correlating simple sonomorphological criteria, such as anechoic areas, with specific histological features. This can be easily achieved even if you buy a portable ultrasound machine .

Over the past few years, color Doppler sonography has become well established as an integral part of head and neck, ENT and maxillofacial surgery, especially as part of the preoperative evaluation of tumors and cervical lymph nodes.

Color duplex sonography

Color duplex sonography (Box 5) is a combination of B-mode sonography, pulsed Doppler sonography, and color coding of perfusion areas. The basic principle of color duplex sonography is the frequency shift of the transmitted signal, which is caused by reflection from moving red blood cells. The speed and direction in which red blood cells approach and move away from the transducer provide the information needed to perform duplex sonography.

The ability to use Doppler signal amplifiers to achieve improved visualization of tumor vascularization has provided new opportunities for tumor characterization. Analysis of microvascularization and time-dependent changes after Doppler amplifier insertion, as well as elastography, are promising new tools for identifying features that help determine whether specific changes are typical for certain types of salivary gland tumors (Fig. 17).

Rice. 17. Study of the salivary glands using power Dopplerography.

Theory and practical experience in ultrasound diagnosis of salivary gland pathology

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In domestic and foreign literature there are many works devoted to sialogy (from the Greek Sialon - saliva and logos - study) - the science of diseases and injuries of the salivary glands, methods of their diagnosis and treatment. According to various authors, diseases of the salivary glands account for up to 24% of all dental pathologies. Currently, in clinical practice, the most common are dystrophic, inflammatory diseases of the salivary glands (sialoadenoses, sialadenitis), as well as tumors and congenital malformations of the salivary glands. In addition, pathological changes in the salivary glands often accompany other diseases (diabetes mellitus, bronchiectasis, sarcoidosis, liver cirrhosis, hypertriglyceridemia, lymphogranulomatosis, etc.).

Various instrumental methods are used to diagnose diseases of the salivary glands [1]:

• radiography (if the formation of stones in the ducts of the salivary glands is suspected, but in 20% of the stones of the submandibular salivary glands and 80% of the parotid salivary glands are non-radiographically opaque);
• sialography (examination of the ducts of the salivary glands with a radiopaque substance, is rarely useful in differentiating tumors from inflammatory processes, but it can help differentiate the mass formation of the salivary glands from formations in neighboring tissues. In patients with suspected autoimmune disease of the salivary glands, a characteristic pattern of saccular expansion may be detected ductal system. In case of acute infection of the salivary glands, sialography should not be performed [2]);
• computed tomography together with sialography;
• ultrasound method (is the most accessible, safe and informative in the process of differential diagnosis of the pathological condition of the salivary glands).

Anatomy of the salivary glands [3]

There are three pairs of major salivary glands (SG) and many small ones. The large ones include paired parotid, submandibular and sublingual SGs. The parotid salivary gland (PSG) is located on the outer surface of the branch of the lower jaw at the anterior edge of the sternocleidomastoid muscle, as well as in the retromandibular fossa. Dimensions vary widely: length 48-86 mm, width 42-74 mm, thickness 22-45 mm. The OSJ is covered by the parotid fascia, which is its capsule and is tightly fused with it. Sometimes, at the anterior edge of the parotid duct, there is an additional lobule measuring 10-20 mm, which has its own duct flowing into the parotid. The parotid duct emerges from the gland at the border of its upper and middle thirds, then it passes along the outer surface of the masticatory muscle parallel to the zygomatic arch and turns 90° inward, penetrating the fatty tissue and buccal muscle. The projection of the parotid duct onto the skin of the cheek is determined on the line connecting the tragus of the auricle and the corner of the mouth. The parotid duct opens in the vestibule of the oral cavity at the level of 1-2 large molars. The diameter of the duct is on average 1.5-3.0 mm, its length is 15-40 mm. The thickness of the gland contains the branches of the external carotid artery, the facial nerve and its branches, and the auriculotemporal nerve. There are many lymph nodes around the OUSG and in its parenchyma (Fig. 1), which can serve as a primary or secondary collector for draining lymph from teeth and oral tissues.

Rice. 1.

Lymph nodes in the thickness of the parotid salivary gland.

The submandibular salivary gland (MSG) is located in the submandibular triangle between the body of the mandible and the anterior and posterior bellies of the digastric muscle. The dimensions of the gland are: anteroposterior 20-40 mm, lateral 8-23 mm, superior-inferior 13-37 mm. Posteriorly, the PNJ is separated from the OSJ by a process of the fascia propria of the neck. The medial surface of the gland in the anterior section lies on the mylohyoid muscle. The submandibular duct, bending over the posterior edge of this muscle, is located on the lateral surface of the hyoglossus muscle. Then it goes between the medial surface of the hyoid gland and the genioglossus muscle to the point of its exit in the area of ​​the hyoid papilla. The facial artery and its branches, the lingual artery and the veins of the same name pass through the gland.

The sublingual salivary gland (SSG) is located on the floor of the mouth in the sublingual region parallel to the body of the lower jaw. The dimensions of the gland are: longitudinal 15-30 mm, transverse 4-10 mm and vertical 8-12 mm. The duct of the parathyroid gland passes along its inner surface and opens in the region of the anterior section of the sublingual ridge independently or together with the submandibular duct. Sometimes the PJS duct flows into the middle section of the PJS duct.

The minor salivary glands - labial, buccal, lingual, palatine, incisive - are located in the corresponding areas of the mucous membrane. They can be a source of development of adenocarcinomas of the oral cavity.

Pathology of the salivary glands

SG malformations are rare. The most common are anomalies in the size of the glands (agenesis and aplasia, congenital hyperplasia (Fig. 2) and hypoplasia), their location (heterotopia, accessory glands), and anomalies of the excretory ducts (atresia, stenosis, ectasia, cystic transformation, ductal dystopia).

Rice. 2.

Hyperplasia of the left sublingual salivary gland.

Sialadenitis is a large group of polyetiological inflammatory diseases of the gastrointestinal tract (Fig. 3). Primary sialadenitis - sialadenitis considered as an independent disease (for example, mumps). Secondary sialadenitis is sialadenitis that is a complication or manifestation of other diseases (for example, sialadenitis with influenza). The echographic picture for different etiologies is not very specific. Etiology has clinical significance in determining treatment tactics.

Rice. 3.

Sialadenitis of the right submandibular salivary gland.

According to the etiological factor, sialadenitis is classified [4] into:

1. sialadenitis developing under the influence of physical factors (traumatic sialadenitis, radiation sialadenitis (Fig. 4) occurs during radiation therapy of malignant tumors of the head and neck);
2. sialadenitis developing under the influence of chemical factors (toxic sialadenitis);
3. infectious sialadenitis (routes of infection penetration into the fluid: stomatogenic (through ducts), contact, hematogenous and lymphogenous);
4. allergic and autoimmune sialadenitis (recurrent allergic, Sjogren's disease and syndrome, etc.);
5. myoepithelial sialadenitis caused by a pathological process, previously designated as a benign lymphoepithelial lesion. The term benign lymphoepithelial lesion was first used by JT Godwin in 1952, replacing the concept of Mikulicz disease;
6. obstructive sialadenitis, which develops when there is difficulty in the outflow of saliva due to obstruction of the excretory duct with a stone (Fig. 5-7) or thickened secretion, as well as due to cicatricial stenosis of the duct. According to the prevalence of the process, they distinguish between focal, diffuse sialadenitis and sialodochitis - inflammation of the excretory duct. The course of the process can be acute or chronic;
7. pneumosialadenitis, which develops when there is air in the gastric tissue in the absence of a bacterial gas-forming infection. Air enters the gland from the oral cavity when the pressure there increases through the duct. Pneumosialadenitis is typical for a number of professions, primarily for glassblowers and musicians playing wind instruments.

Rice. 4.

Post-radiation sialadenitis.

Rice. 5.

Stone of the duct of the submandibular salivary gland.

Rice. 6.

Stone in the parenchyma of the submandibular salivary gland.

Rice. 7.

Stone in the duct of the submandibular salivary gland.

Tumors of the salivary glands

Tumors of the salivary glands are divided into two groups: epithelial and non-epithelial. Epithelial tumors predominate in adults (95%). In children with SG, epithelial and non-epithelial tumors are equally common. In addition to true tumors, processes resembling tumors (tumor-like lesions) develop in the GS.

Among epithelial tumors of the gastrointestinal tract, benign neoplasms are distinguished, as well as malignant ones - carcinomas.

Benign epithelial neoplasms of the stomach include ductal papillomas, adenomas and benign sialoblastoma. SG adenomas are divided into two groups: polymorphic (the most common SG adenoma) and monomorphic (all other) adenomas. Tumors of different structure, origin and prognosis were artificially included in the group of monomorphic adenomas.

Pleomorphic (polymorphic) adenoma (mixed tumor of the gland) is a adenoma of the gland, built from two types of cells: ductal epithelium and myoepithelial cells. Macromorphological picture. The tumor is usually an elastic or firm nodule of lobulated grayish-white tissue, usually partially encapsulated. Typical of a pleomorphic adenoma is the so-called chondroid stroma, resembling hyaline cartilage. Variants of the echographic image of pleomorphic adenomas are presented in Figure 8.

Rice. 8.

Pleomorphic adenoma of the gastrointestinal tract.

Warthin's tumor is an adenolymphoma in which multiple cystic cavities are formed, covered with double-layered epithelium. The papillae protrude into the lumen of the cysts. A pronounced proliferation of lymphoid tissue occurs in the tumor stroma. This tumor almost exclusively develops in the parotid gland.

Other types of benign tumors are less common. These are benign oncocytoma (oxyphilic adenoma), basal cell adenoma, tubular adenoma, benign cystadenoma sialoblastoma.

Among benign primary non-epithelial tumors, the most common are hemangioma, lymphangioma, neurofibroma and lipoma.

Among malignant non-epithelial tumors, malignant lymphomas are more often found (they arise, as a rule, against the background of myoepithelial sialadenitis, Sjögren's disease and syndrome).

Tumor-like lesions of the salivary glands

Rice. 9.

Salivary gland cysts.

1. Salivary gland cysts (mucoceles). There are two types of mucocele of the gland: the retention type (retention cyst of the small gland, formed when saliva is retained in the excretory duct) and the type of interstitial secretion, when, when the wall of the duct is injured, saliva enters directly into the fibrous tissue surrounding the gland. Mucoceles in the floor of the mouth are also called ranulae.
2. Cysts of the excretory ducts of large SGs are pronounced dilatation of the excretory duct due to retention of secretions in it. Blockage of salivary outflow can be caused by various reasons: tumor, stone, thickened mucus, post-inflammatory stenosis, even cicatricial obliteration of the lumen.
3. Sialoadenosis (sialosis) is a non-tumor and non-inflammatory symmetrical increase in SF due to hyperplasia and hypertrophy of secretory cells. The outcome of sialosis is often SG lipomatosis. The process has a chronic relapsing course. Sialosis occurs in a number of diseases and conditions: diabetes mellitus, hypothyroidism, malnutrition, alcoholism, liver cirrhosis, hormonal disorders (hypoestrogenemia), reactions to medications (most often antihypertensive), neurological disorders.

Adenomatoid hyperplasia of small SGs leads to their increase to 0.5-3.0 cm in diameter. The causes of adenomatoid hyperplasia are trauma and prolonged exposure to ionizing radiation.

Oncocytosis is age-related changes in secretory cells and epithelium of the ducts of the gastrointestinal tract. In this case, the SF may slightly increase, but usually their value does not change.

To summarize, I would like to note that ultrasound using Doppler sonography in many of our observations helped to accurately determine the nature of the pathological process in the gastrointestinal tract. However, this diagnostic method does not allow one to unambiguously confirm or refute the malignant nature of the formation of the salivary glands.

Literature

1. Benign and malignant tumors of soft tissues and bones of the face. A.G. Shargorodsky, N.F. Rutsky. M.: GOU VUNMTs, 1999.
2. Topographic anatomy and operative surgery. I.I. Kagan, S.V. Chemezov. M.: GEOTAR-Media, 2011.
3. Salivary glands. Diseases and injuries. V.V. Afanasiev. M.: GEOTAR-Media, 2012.
4. Inflammatory diseases of the tissues of the maxillofacial area and neck. A.G. Shargorodsky. M.: GOU VUNMTs, 2001.

Ultrasound machine RS85

Revolutionary changes in expert diagnostics.
Impeccable image quality, lightning-fast operating speed, a new generation of visualization technologies and quantitative analysis of ultrasound scanning data.

Summary

Ultrasonography has established itself as the primary imaging technique in the diagnosis of salivary gland diseases. Sonographic examination is usually sufficient to diagnose sialolithiasis. If chronic sialoadenitis or sialoadenosis is suspected, and sonographic data are insufficient, standard sialography may be required in some cases. A histological examination is necessary as soon as the diagnosis of a neoplasm is established. If the tumor's enlargement and connection with surrounding tissues cannot be determined sonographically, subsequent computed tomography or magnetic resonance imaging should be performed. To conduct research, we recommend using a device from GE Voluson E8 .

Operations

To remove the cyst together with P. g. An incision is made in the sublingual area. When isolating a cyst and gland, it is necessary to insert a probe or catheter into the duct of the submandibular gland to avoid injury to it. Isolation of pancreas. should start from the distal pole. In cases where part of the cyst is localized below the mylohyoid muscle, B. D. Kabakov proposed performing the operation in two stages. At the first stage, after dissecting the tissue in the submandibular or submental region, the cyst shell is isolated to its narrowed part at the mylohyoid muscle. This isthmus (the narrow part of the cyst) is ligated and divided. The part of the cyst separated from the surrounding tissue is removed. The wound is sutured in layers, leaving a small opening. At the second stage, the cyst is opened from the bottom of the mouth, widely excising the mucous membrane of the sublingual region covering the cyst, as well as the membrane of the cyst. After this, the cyst wall is sutured with knotted sutures to the edges of the mucous membrane of the sublingual region. The cyst cavity is packed.

See also Salivary glands.

Bibliography:

Kasatkin S.N. Anatomy of the salivary glands, Stalingrad, 1948; Guide to surgical dentistry, ed. A. I. Evdokimova, p. 226, M., 1972, bibliogr.; Sazama L. Diseases of the salivary glands, trans. from Czech., Prague, 1971, bibliogr.; Solntsev A. M. and Kolesov V. S. Surgery of the salivary glands, Kyiv, 1979, bibliogr.; Rauch S. Die Speicheldrusen des Menschen, Stuttgart, 1959.

I. F. Romacheva; V. S. Speransky (an., hist.).