Cancer of the salivary gland

Acinocellular carcinoma of the salivary gland was first considered as a serous-cellular adenoma. However, in 1954 Foote and Frazel found that this tumor is aggressive and has an infiltrative growth and metastasizes. They considered it as a differentiated form of the acinosis-cell adenocarcinoma of the SJ and found that most of the acinosis-cell tumors with adequate treatment are curable.

In the subsequent classification of WHO in 1972, it was considered an acinotic cell tumor. At present, the term "acinocellular tumor" is not correct, since the malignant potential of the neoplasm is clearly established. Acinocellular carcinoma is a malignant epithelial tumor of the SJ in which some of the tumor cells show signs of serous acinous differentiation that are characterized by cytoplasmic secretory granules of the zymogen. The cells of the ducts of the SC are also a component of this tumor. The code is 8550/3.

Synonyms: acinosis-cell adenocarcinoma, acinar-cell carcinoma.

Women fall ill with cancer of the salivary gland somewhat more often than men. Patients with AK belong to very different age groups - from small children to older people, with almost equal distribution in age groups from 20 to 70 years. Up to 4% of patients are under the age of 20 years. In the overwhelming majority (over 80%) of cases, AK is localized in the parotid gland, followed by small SL of the oral cavity (of the order of 1-7%), about 4% - submandibular SLE and up to 1% - sublingual SLE.

Clinically, the salivary gland cancer usually manifests itself as a slowly growing solid non-fixed tumor in the parotid region, although in the case of multifocal growth, the tumor is fixed to the skin and / or muscle. U '/ 3 patients have complaints of pain of an intermittent or uncertain nature, and 5-10% have symptoms of paresis or paralysis of facial muscles. Duration of symptoms - on average less than a year, but in rare cases can reach several years.

The cancer of the salivary gland initially spreads with regional metastasis to the lymph nodes of the neck. Then there are distant metastases - most often in the lungs.

Macroscopically it is a dense solitary tumor without a clear distinction from the surrounding tissue of the gland. Dimensions vary from 0.5 to 2, less often - to 8 cm, on the cut - grayish-white, in places brown with cavities filled with a brownish liquid, or with serous contents. Cystic formations of various sizes are surrounded by a solid glandular loose tissue. In some cases, the surface of the tumor is solid, creamy-gray, without cystic cavities. Density of the node varies depending on the ratio of solid and cystic components. The tumor is in the capsule, but the capsule may not be all over. Recurrent tumors usually of a solid nature, with foci of necrosis, do not have a capsule; on the cut, the surface of the tumor does not resemble a pleomorphic adenoma with its slippery, shiny, bluish-translucent tissue. Multifocal growth of the tumor, invasion of the vessels was noted. Ultrastructural studies reveal the similarity of tumor cells with serous acinar elements of the end sections of the SC.

The microscopic picture reveals signs of infiltrative growth. Rounded and polygonal cells have a granular basophilic cytoplasm, a well-defined cell membrane, some cells are vacuolated. Sometimes cells have a cubic form, and sometimes the cells are so small that they lose clear contours; reveals the polymorphism of cells, the figure of mitosis. Tumor cells have the characteristic of epithelial cells, chaotically forming a solid, trabecular pattern, bands and nests, acinous and glandular formations. Cells form solid fields, less differentiated cells form follicle-like and ferruginous structures. Stromal fibrovascular interlayers are narrow, have thin-walled vessels, there are foci of necrosis, calcification. The main characteristic features of this form of tumor are mainly solid structure, similarity with serous acinar cells, homogeneity of tumor cells and the absence of glandular structures, specific granularity of the cytoplasm.

Histologically, proceeding from differentiation of cells towards serous acini, a number of morphological types of growth and types of tumor cells are possible. Specific types - acinous, protocol, vacuolated, light-celled. Nonspecific types - glandular, solid lobular, microcystic, papillary-cystic and follicular. Acinous cells are large, polygonal, with a slightly basophilic granular cytoplasm and a round, eccentrically located nucleus. Cytoplasmic zymogen granules give a positive Schick reaction, are resistant to diastase, mucicarmine stains lightly or does not stain at all. Nevertheless, the Schick reaction can sometimes be focal and can not be seen immediately. The ducts are smaller in size, eosinophilic, cubic in shape with a centrally located nucleus. They surround the gaps of various sizes. Vacuolated cells contain cytoplasmic Schick-negative vacuoles of various sizes and variable in number. Light cells in shape and size resemble acinous, but their cytoplasm is not stained either by routine methods or by a Schick reaction. The glandular cells are rounded or polygonal, oxyphilic with a rounded nucleus and rather fuzzy boundaries. They often form syncytial beams. The glandular cell variant is represented by predominant cells with very small cytoplasmic granularity. The intensity of cytoplasmic staining depends on the granularity of cells that closely resemble the proenzymatic granules of serous SSC cells. This similarity is not only the appearance, distribution, density of location, but also the ability of intensive staining with hematoxylin, eosin and PAS. These cells do not contain mucus, fat or silvery granules; there are vacuoles, cysts and free spaces. Cells are located between the cysts in a solid mass or form lacy glandular and acinar structures. The scanty stroma of the tumor consists of a richly vascularized connective tissue with rare accumulations of lymphatic elements.

With a solid type of structure, tumor cells fit tightly to each other, forming bundles, nodes and aggregates. In the microcystic type is characterized by the presence of many small spaces (from a few microns to millimeters). Pronounced cystic cavities larger than the microcystic type, partially filled with papillary epithelial proliferation, characterize the cystic papillary (or papillary-cystic) type. In this variant, secondary changes are particularly often seen in the form of pronounced vascularization, hemorrhages of different prescription, and even with signs of hemosiderin phagocytosis by tumor cells of the cyst lumens. The follicular type is characterized by multiple cystic cavities lined with epithelium and filled with eosinophilic protein content, which resembles follicles of the thyroid gland with a colloid. It is possible to see psammom bodies, which are sometimes numerous and are found during cytological examination after fine needle biopsy.

In spite of the fact that more often the cancer of the salivary gland has any one cellular type and variant of growth, in many cases combinations of both cellular and morphological types are observed. Acinosis-cell and protocol cell types predominate, while all others are much less common. Thus, the clear-cell variant is found in no more than 6% of cases for cancer of the salivary gland. It usually has a focal character and rarely presents diagnostic difficulties. The clear cell version has a cytoplasm of water color. Cells do not contain glycogen, fat or a PEA-positive material in the cytoplasm. The core is centrally located, round, bubble-shaped and dark with indistinct nucleols. There are no mitotic figures. The cell membrane very clearly surrounds the cell. Light cells form solid or trabecular clusters with a small number of glandular or acinar structures. Among the architectural types more often than others there are solid lobular and microcystic, followed by papillary-cystic and follicular.

In many cases of AK, pronounced lymphoid infiltration of the stroma is detected. The presence and severity of this infiltration have no prognostic significance, but more often it occurs in less aggressive and clearly delineated AK with a microfilpicular type of structure and a low proliferative index. Such a cancer of the salivary gland is separated by a thin fibrous pseudocapsule and surrounded by lymphoid infiltrates with the formation of centers of reproduction.

Electron microscopy reveals rounded dense multiple cytoplasmic secretory granules characteristic of cells of the acinous type. The number and size of the granules vary. Rough endoplasmic reticulum, a lot of mitochondria and rare microvilli are also characteristic ultrastructural signs. In some cells, vacuoles of different size and shape are detected. The basal membrane separates the groups of the acinous and duct cells from the stroma. It was found that light cells at the light-optical level are the result of formal changes or expansion of the endoplasmic reticulum, inclusions of lipids, enzymatic degradation of secretory granules, and the like.

An ultrastructural study of tumor acinous cells revealed a specific type of secretory granule in the cytoplasm of many cells similar to granules of normal serous cells of the salivary acini. Some researchers have discovered two types of cells: with secretory granules in the cytoplasm and without them. The latter contain well-developed organelles. Secretory granules were localized in the apical part of the cytoplasm. The cytoplasm of some cells was almost completely filled with secretory granules, but in the cytoplasm of other cells there were very few of them. In such cells, organelles were rare, with a small number of mitochondria. The plate complex and endoplasmic reticulum are indistinguishable. However, neoplastic cells without secretory granules contained well-developed cytoplasmic organelles. They abounded in the endoplasmic reticulum and a number of mitochondria. The lamellar complex was visible in many cells. The surface of cells filled with secretory granules was smooth, but their microvilli at the edge of the cell did not have secretory granules. The ribosomes were located opposite the cytoplasmic and nuclear membranes. There was a transition between light cells and duct cells that have grooves.

Histogenetically acinous tumor cells originated from mature serous acinus SLE cells as a result of malignant transformation of terminal duct cells with histological differentiation towards acinus cells. Nevertheless, it has been shown that a normal acinous cell can undergo mitotic division and some cancer of the salivary gland can result from the transformation of this type of cells. Morphological, histochemical and ultrastructural studies have shown the similarity of tumor cells to serous ones, confirming theoretical concepts. The secretory activity of tumor cells is similar to that of normal serous acinus SLE. Clear-celled cancer of the salivary gland, being a separate tumor in the morphological sense, develops, probably, from the striatal cells of the duct.

Low-differentiated cancer of the salivary gland is characterized by pronounced cellular polymorphism, high proliferative activity, frequent mitosis, which is confirmed by their worst prognosis.

More often, the stage of the disease is the better predictive factor than the definition of the "wallet" of the tumor. The large size of the tumor, the spreading of the process to the deep parts of the parotid gland, signs of incomplete and insufficiently radical resection of the tumor - all this indicates a poor prognosis. With regard to the proliferative activity of the tumor, the most reliable marker is the Ki-67 labeling index itself. When this index is less than 5%, there is no recurrence of the tumor. With a Ki-67 labeling index of 10% or higher, most patients have a very poor prognosis.

[1], [2], [3], [4], [5]

Mucoepidermoid carcinoma of the salivary gland

Mucoepidermoid cancer of the salivary gland has been known under various terms since 1921. In 1945, FW Stewart et al. Presented a description of the tumor under the term "mucoepidermoid tumor", reflecting its histological structure. This malignant glandular epithelial tumor, characterized by mucous, intermediate and epidermoid cells with columnar, clear cell and oncocytic traits. The code is 8430/0.

Synonyms: mixed epidermoid and mucinous carcinoma.

Studies of foreign and domestic pathomorphologists and clinicians were the basis for introducing the mucoepidermoid tumor into the carcinoma group. According to the clinical and morphological features, a well-differentiated type with a low degree of malignancy and a low-grade type with a high degree of malignancy are distinguished. Some researchers also distinguish an intermediate type - moderately differentiated with an average degree of malignancy. However, L. Sikorowa, JW Meyza (1982) believe that there are no sufficiently clear histological criteria for isolating the intermediate type.

Macroscopically, a salivary gland cancer with a low degree of malignancy usually has a clear demarcation line from the surrounding tissue, but has no capsule, shows signs of infiltrative growth. The size of the tumor is from 2 to 5 cm. The tumor node on the cut is with a mucous surface, cystic cavities are often revealed; sometimes the neoplasm is represented by one or more cystic cavities. A tumor with a high degree of malignancy has dimensions from 3 to 10 cm, dense, immobile, infiltrates surrounding tissues, without cystic cavities, with hemorrhages and necrosis areas. The superficial cancer of the salivary gland has a bluish-reddish color and can simulate mucocele or vascular lesion. The mucous membrane above the tumor, localized in the palate, may have papillary appearance. Sometimes the erosive surface of the bone is visible.

Microscopically the cancer of the salivary gland is represented by various cellular types: undifferentiated, intermediate, epidermoid, light and mucus-producing cells. Undifferentiated cells are small, somewhat larger than the lymphocyte, round or oval with a small round nucleus. Chromatin is intensely stained with hematoxylin. The cytoplasm is basophilic. These cells do not contain mucus and PAD-negative. They form solid layers and strands often on the periphery of the tubules and epithelial layers of more differentiated cells. Undifferentiated cells can differentiate into intermediate, light, epidermoid and mucus-producing cells in two directions - epidermoid and glandular. Differentiation into epidermoid cells is weak and indirect, through intermediate cells. Differentiation into glandular cells mainly occurs directly. Intermediate cells (cells lacking any specificity) are more undifferentiated. It has a small vesicular nucleus and an eosinophilic cytoplasm. The number of them is different, but in many cases they make up the majority of the tumor component. The result of their pluripotent differentiation are goblet, light and epidermoid cells.

Epidermoid cells have medium dimensions, round or polyhedral. Their cytoplasm is acidophilic, the nucleus is vesicle-like, contains nucleols. Also, like undifferentiated cells, they form solid napladstvovaniya, strands, can lining cystic cavities. Keratogialin and desmosomes make them similar to squamous epithelial cells.

Light cells are diverse in size and shape, they have a light, transparent ("empty") cytoplasm containing glycogen. The nucleus is shallow, bubbly or pycnotic, located in the center or on one side of the cell. These cells form solid fields adjacent to the cysts, or are located among groups of undifferentiated and intermediate cells.

Mucus producing cells are large, cuboidal and cylindrical, but in most cases are goblet-shaped. Usually they make up no more than 10% of the tumor. The small nucleus is located eccentrically or on the periphery of the cell. The fibrillar or reticular cytoplasm is slightly basophilic and is intensely stained with mucicarmin, the result of the secretion of mucus that accumulates in the cell cytoplasm. Mucous secret, penetrating the interior of the stroma, forms mucous lakes. Goblet cells lining the salivary "ducts" and cysts, often being the only element of the lining. They differentiate from intermediate and undifferentiated cells. Mucus-forming cells are one of the variants of differentiation of tumor cells into the terminal mucous secretory sections of the SJ.

In a more differentiated type with a low degree of malignancy, cystic structures of various sizes predominate, with the predominant content of mucus penetrating into the stroma. They are surrounded by intermediate, undifferentiated and light cells. The stroma is mostly copious, fibrous, sometimes hyaline. Nerve necrosis invasion, high mitotic activity, or cellular atypia are rare. Lymphoid infiltration along the edge of the tumor with the formation of centers of reproduction can mimic invasion of the lymph node.

A microscopic pattern of a well-differentiated type is distinguished by cellular polymorphism and predominantly cystic structures filled with mucus; The less differentiated type is more monotonous. The proportion of different cell types can vary both among different MCs and within a single tumor. Salivary gland cancer usually has a multi-cystic structure with a solid component, which sometimes predominates. Some tumors have clear boundaries, but the infiltration of the adjacent parenchyma is obvious. In the tumor, all described types of cells can be represented, but intermediate and epidermoid prevail. They form solid nests of various sizes and shapes with a monotonous structure of small cells infiltrating the stroma. The cellular atypia is expressed, the figures of mitosis are frequent. The regions of small cells with mitosis figures can be found among single goblet cells, and there are also regions of tiny cysts with mucus secreting cells. In rare cases, populations of oncocyte, light and / or bar cells may predominate. In light cells, there is little mucin, but glycogen content is detected. Often there is focal sclerosis and / or mucous extravasates with inflammatory infiltration. A sclerosing cancer of the salivary gland is described.

Taking into account the origin of mucoepidermoid tumors, it is important to know about the presence of goblet and epidermoid cells in the epithelium of salivary ducts in both the physiological and pathological states. According to the data of ultrastructural studies, in the pathological state the epithelial duct cells can differentiate in the glandular and epidermoid directions. The reshaping of spine-shaped cells occurs through the formation of intermediate cells. Mucoepidermoid carcinoma consists of cells that result from the modification of undifferentiated cells. This is a sign that the mucoepidermoid tumor originates from the cells of the salivary duct or develops as a result of the modification of the cells located under the cylindrical cells of the interlobar or large salivary duct. Myoepithelial cells in MC have not been found, which confirms the concept of development of these tumors from large salivary duct cells, among which myoepithelial cells do not occur.

Microscopically differential diagnosis between the cystic variant of MC and cyst is based on the presence of uniformity of the cyst lining and the absence of signs of infiltrative growth. The presence of mucus-forming cellular elements, the absence of signs of keratinization help in the differential diagnosis of a low-grade variant of MC with a predominance of epidermoid cells.

Several systems for determining the degree of differentiation of MC have been proposed, but none of them is generally accepted. Nevertheless, the system, based on five histological signs, has shown its effectiveness.

Highly differentiated tumors behave more aggressively when localized in the submandibular SC.

The reaction with high-molecular cytokeratins in immunohistochemical studies can help in the determination of epidermoid cells with a small amount in the tumor.

Adenoid cystic cancer of the salivary gland

Adenoid cystic cancer of the salivary gland develops in the salivary and mucous glands. In the literature, the tumor was described under the term "cylinder", proposed in 1859 by Billroth, and reflecting the structure of the intercellular substance of the tumor. The term "adenoid cystic carcinoma", proposed by J. Eving, in the opinion of the majority of clinicians and pathomorphologists, takes into account the malignant nature of the tumor, reflects its clinical and morphological features.

Adenoid cystic cancer of the salivary gland is a basaloid tumor consisting of epithelial and myoepithelial cells in various morphological configurations, including tubular, crooked and solid types of growth. The code is 8200/3.

Macroscopically, the tumor can look like a relatively limited node or infiltrate, usually unencapsulated. Tumor infiltrate extends to the surrounding tissue, there are hemorrhages and cystic degeneration.

On a cut the fabric is homogeneous, partly moist, gray-white, yellow-gray or light-brown.

Microscopically often reveals perineural spread of the tumor. Cellular elements are generally represented by small cells with rounded or oval nuclei, scant cytoplasm and poorly discernible boundaries. Mitoses are rare. There are cells with a dark path, slightly eosinophilic cytoplasm, forming glandular structures. Among the irregular form of cell masses, there are rows of cysts or alveolar spaces that create the so-called crooked areas that characterize the direction of these tumors. The glandular structures are filled with hyaline, which gives a PBS-positive reaction. Sometimes the crooked structures alternate with solid or cystic areas. Heavens and layers of cells pass in the hyaline stroma and form round or oval cell masses of various sizes and shapes. The crooked areas can be large and formed by small groups of cells scattered in the fibrous and / or hyaline stroma. Depending on the infiltrative properties of tumor cells, the following types are distinguished: when open spaces or cavities predominate over glandular or solid areas; when a solid tissue (especially connective fibrous tissue) or infiltrated skeletal muscle is present in the tumor; this type is common. The tumor stroma is hyaline and gives a positive metachromatic reaction. There are no chondroid or mixochondroid components.

Ultrastructural studies have shown that adenoid-cystic carcinoma consists of two types of cells - epithelial secretory (ductal) and myoepithelial. Tumor myoepithelial cells are very similar to one of the normal cell types of the insertion duct. Modified myoepithelial cells usually have a hyperchromic pointed nucleus and often a light cytoplasm. Serous cells, polyhedral forms - undifferentiated, with a rich nuclear-cytoplasmic ratio. PLA-positive, hyaline-containing cysts and pseudo-iron structures are represented by a reduplicated basal membrane produced by tumor cells.

There are three different types of structure: tubular, crooked and solid, or basaloid. In the tubular type, well-defined tubules and ducts with central lumens are lined with an inner layer of epithelial and external - myoepithelial cells. The most common type of crooked type is characterized by nests of cells with cylindrical cystic cavities. They are made with hyaline or basophilic mucous contents. A solid, or basaloid, type is formed by bundles of monotonous basaloid cells in the absence of the formation of tubular or microcystic structures. When the cryogenic and solid types are constantly present, small true channels, but they may not always be clearly visible. Each of these types can predominate or, more often, be part of a complex tumor structure. The tumor stroma is usually hyalineized and can exhibit mucinous or mucous symptoms. In some tumors, there is a sharp stromal hyalinosis with compression of the epithelial component. Peri neural or intranural invasion are common and frequent signs of ACC. The tumor can extend along the nerve over a significant length without clinically visible signs of malignancy. In addition, the tumor can infiltrate the bone before the appearance of radiologic signs of its destruction.

Adenoidokistozny cancer of the salivary gland is occasionally found together with other neoplasms (tumor-hybrid). According to the results of the study of recurrent and metastatic tumors, the possibility of transformation of ACC into pleomorphic carcinoma or sarcoma is reported.

Prognostic and predictive factors - factors affecting survival - include for ACC: histological type, tumor localization, clinical stage, the presence of bone damage and the condition of the surgical margins of resection. In general, tumors consisting of crooked and tubular structures are less aggressive than those having solid sites occupying 30% or more of the tumor area. Along with the histological type, the clinical stage of the disease has a significant effect on the prognosis. According to other researchers, attempts to confirm the predictive value of "Grad" failed. The prognostic significance of the clinical stage and tumor size was reconsidered as the most constant factors of the clinical outcome in these patients. The five-year survival rate is 35%, but the more distant results are significantly worse: from 80 to 90% of patients die from the disease in 10-15 years. Local relapses, according to various data, occur in 16-85% of the observations of these tumors. Relapse is a serious sign of incurability. Lesion of lymph nodes is infrequent and varies in the range of 5-25%, usually more often in tumors with localization in the submandibular SJ, which is more likely due to the direct spread of the tumor to the lymph node, rather than to metastasis. Remote metastases are observed in 25-55% of cases of ACC, more often others are affected by the lungs, bones, brain and liver. Only 20% of patients with distant metastases live 5 years or more.

The effect of perineural infestation on survival is controversial. Broad radical local excision with subsequent irradiation or without it is a method of choice therapy. Only radiation therapy or a combination of chemotherapy with the treatment of relapse and / or metastasis gives limited success. Nevertheless, radiotherapy improves the results with local exposure to a microscopically residual tumor. The value of the chemotherapeutic method of treatment in ACC is limited and needs further study.

[6], [7], [8], [9], [10], [11]

Epithelial-myoepithelial cancer of the salivary gland

Salivary gland cancer, consisting of two types of cells in different ratios, which usually form a type of ductal structure. Biphasic morphology is represented by an internal layer of lining the ducts - cells of the epithelial type and an outer layer of light cells of the myoepithelial type. Code - 8562/3.

Synonyms: adenomyoepithelioma, light celled adenoma glycogen-rich adenoma glycogen-rich adenocarcinoma light-cell adenocarcinoma

Epithelial-myoepithelial cancer of the salivary gland occurs in 1% of all tumors of the SC. Women are more often ill - 2: 1. The age of the patients is between 13 and 89 years; The peak incidence is observed in the age group 60-70 years. In pediatric practice, 2 cases of diseases have been described. Epithelial-myoepithelial carcinoma is localized more often in large SSs, especially in the parotid gland (60%), but small SL of the oral cavity, upper respiratory and digestive tracts can also be affected.

The clinical picture of epithelial-myoepithelial cancer of the salivary gland is represented by a painless, slowly growing tumor. Occurring in small SL the cancer of the salivary gland is often ulcerated, representing submucosal nodes with fuzzy edges. Rapid growth and / or tenderness of the facial nerve suggest the presence of tumor sites with a low degree of differentiation.

Macroscopically epitope-myoepithelial cancer of the salivary gland is characterized as a multinodular formation with an expansive type of growth in the edges and the absence of a true capsule. Surface of the tumor lobed, solid. Cystic cavities may be present. The tumor of small SJ is poorly delimited from surrounding tissues.

Histologically, epithelial-myoepithelial cancer of the salivary gland has a lobate growth type with a mixed-tubular and solid-type structure. Papillary and cystic areas can be identified in 20% of cases. Tumors of small SJ can infiltrate surrounding tissues. Ulceration of the covering tumor of the mucosa occurs in about 40% of cases.

Pathognomonic histological evidence of epitope-myoepithelial carcinoma is the presence of two-layered duct structures. The inner layer is formed by one row of cubic cells with a dense fine-grained cytoplasm and a central or basal arrangement of the nuclei. The outer layer can be represented by one or more layers of polygonal cells with clearly defined boundaries. The cytoplasm has a characteristic luminous appearance, and the nucleus is slightly eccentric, vesicular. The two-layered structure type is preserved in cystic and papillary areas, but solid areas can be formed exclusively by light cells. The hyaline main membrane surrounding the lobules of the tumor gives them an organ form. Organ structures - of various sizes with tubules in the center, lined with very small, cuboidal and formless, dark epithelial cells. Their nuclei are large, dark-colored, contain two or three nucleosides. The cytoplasm is meager, mitoses are rare. These cells are similar to the cells of the interlobular duct of normal SC. They contain few organelles and produce a small amount of secretion. Schick-positive, hyaline eosinophilic bundles of material, like a basal membrane, surround the duct structures and separate light cells in solid areas. Cells of the outer layer are rich in glycogen and other organelles. They show myoepithelial differentiation. The nuclei of light cells are small, oval or fusiform and localized near the basal membrane and parallel to it. There are some tumors in which the light cells predominate and their solid structure resembles a hypernehroma, a parathyroid adenoma, or a clear cell type of an acinosis cell carcinoma. Previously, this cancer of the salivary gland was classified as myoepithelial adenomas or ductal carcinomas. Characterized by infiltrative growth and metastasis.

Coagulation necrosis in the central parts of tumor nodes is infrequent. In rare cases squamous metaplasia and spindle-shaped cells, as well as oncocytic changes in the cells of the inner layer of the ductal structures, can be observed.

Perineural and vascular invasion are frequent, and invasion into the underlying bone can also be observed.

In the light-cell population, epithelial-myoepithelial cancer of the salivary gland can be determined from 0 to 1 -2 mitoses in the field of view. Rare cases of dedifferentiation are described

Prognostically, relapses occur in about 40%, and metastases occur in 14% of cases. The most frequent localization of metastases is cervical lymph nodes, lungs, liver and kidneys. Up to 10% of patients die from the disease and its complications. 5- and 10-year survival rates are respectively 80 and 72%.

With a more unfavorable prognosis, tumor size and rapid growth are associated. The main prognostic factor is the state of the edges of the wound after excision of the tumor. In small SJ, the prognosis is worse, which is probably due to the difficulties, and sometimes the impossibility of radical tumor removal. Atypia worsens the prognosis in the presence of its signs in 20% or more of the tumor cells. Aneuploidy, a high mitotic index, dedifferentiation sites predict a worse outcome, metastases and relapses with them develop in 70% or more patients.

[12], [13], [14], [15], [16], [17]

Clear cell carcinoma of the salivary gland

Malignant epithelial tumor, consisting of a homogeneous population of cells that have a optically light cytoplasm with standard staining with hematoxylin and eosin. Due to the fact that often the cancer of the salivary gland has a clear cell component, the light-cell carcinoma differs from them by the monomorphicity of the clear-cell population and the absence of any characteristics characteristic of other tumors of the SC. The code is 8310/3.

Synonyms: light-cell adenocarcinoma, a hyalineizing clear-cell carcinoma.

Clear-celled salivary gland cancer can be confused with epithelial-myoepithelial cancer, which was even described as a clear cell carcinoma.

The peak incidence falls on 40-70 years, the tumor is practically not found in children. There is no predisposition towards sex.

Localized light-cell carcinoma most often in small SJ of the oral cavity. In this case, the palate is most often affected, although the tumor can meet in the glands of the mucous membrane of the cheeks, tongue, bottom of the mouth, lips, retro-molar and tonsillar regions.

Clinically, the only permanent sign is the appearance of swelling; Pain and ulceration of the mucous membrane are much less common. It is reported that until the diagnosis is made, the tumor can exist in the patient from 1 month to 15 years.

Macroscopically, the cancer of the salivary gland, despite its relatively small size (usually no more than 3 cm in diameter), the tumor has no clear boundaries, and there are often signs of infiltration of surrounding tissues - salivary gland, mucous membrane, soft tissues, bones and nerves. The surface of the cut is grayish-whitish.

Histologically, the clear-celled cancer of the salivary gland is characterized by a monotonous population of round or polygonal cells with a light cytoplasm. In rare cases, a small percentage of cells have a pale oxyphilic cytoplasm. The nuclei are located eccentrically, have a rounded shape, often contain small nucleoli. With the help of a Schick reaction, a different amount of glycogen can be detected in the cytoplasm of tumor cells. Some authors distinguish, according to this feature, the so-called "bright cell carcinoma, rich in glycogen". When staining with mucicarmine, cytoplasmic mucins are usually absent. Tumor cells form bundles, nests, solid foci - there are no ductal structures in the clear cell carcinoma. Fission patterns are rare, but in some tumors there are signs of moderate nuclear polymorphism. In the hyalineizing type of clear cell carcinoma, the stroma consists of broad collagen bundles, and in other types it is represented by thin fibrous septa, which may be cellular or slightly collagenous. Clear cell carcinoma does not have a capsule and has signs of an infiltrative tumor.

Immunohistochemically, the clear-celled cancer of the salivary gland, at least focal, is positive for cytokeratin. Expression of protein B-100, vimentin, CPAP and actin has a variable character. In the presence of histological and immunohistochemical signs of myoepithelial differentiation, the tumor is better classified as a clear-cell variant of myoepithelioma or myoepithelial cancer.

Electron microscopy reveals dense connections, desmosomes, tonofilaments, microvilli and basal membrane, i.e. Signs of duct differentiation.

Thus, the histogenesis of clear cell carcinoma, as confirmed by ultrastructural data, is associated with ductal, and not with myoepithelial differentiation.

The prognosis of clear cell carcinoma is very good. A small number of tumors gives metastases to the regional lymph nodes and, much less often, to the lungs. Cases with a fatal outcome of the given disease are not described.

[18], [19], [20], [21]

Mucinous cancer of the salivary gland

A rare malignant tumor consisting of epithelial clusters with large lakes of extracellular mucin. The mucinous component usually occupies the bulk of the tumor mass. The code is 8480/3.

Macroscopically, the mucinous cancer of the salivary gland has a nodal structure and slightly defined boundaries. The surface of the cut is greyish-whitish, contains a number of cystic cavities filled with viscous jelly-like contents.

Histologically, the cancer of the salivary gland consists of irregularly shaped nests and groups of neoplastic cells floating in mucus-filled cystic cavities separated by bundles of connective tissue. Tumor cells have a cubic, cylindrical or irregular shape, their cytoplasm is usually light, and the cores - hyperchromic, are located centrally. The nuclei of tumor cells can show atypy, but the fission patterns are very rare. Cells of neoplasm are assembled into groups (clusters) and tend to form secondary lumens or incomplete structures of the protocol species. Mucus-forming cells can build papillary structures that extend into slime lakes. There may also be islands of tumor-forming mucus cells of the acinus type. The intracellular and extracellular mucous contents of the Schick-positive are also colored with alcian blue and mucicarmin.

Immunoprofil cells of mucinous adenocarcinoma - pancitokeratin, as well as cytokeratins 7, 8, 18 and 19, i.e. Those that are usually found in simple epithelium. Approximately 10-20% of cases show a positive reaction with cytokeratins 4 and 13. Tumor cells are negative for the expression of 5/6, 10, 14, 17 cytokeratins and smooth muscle actin.

Electron microscopy makes it possible to detect in the densely packed cytoplasm of tumor cells a lot of drops of mucus of low electron density. Serous-mucosal drops are also found. On the side of the cells facing the lumen, you can see randomly arranged microvilli.

Differential diagnosis in mucinous adenocarcinoma includes mucoepidermoid cancer of the salivary gland, a mucin-rich variant of the protocol of the cancer of the SC and cystadenocarcinoma. In MK you can see extravasates of mucus, but the tumor itself consists of epidermoid and intermediate cells. In cystadenocarcinoma and AK, cystic cavities lined with epithelium are found, however, extracellular mucus lakes are not characteristic of these tumors.

In terms of prognosis, it should be noted that the mucinous cancer of the salivary gland is not sensitive to radiation therapy and tends to relapse and metastasize to the regional lymph nodes.

Oncocytic cancer of the salivary gland

It is characterized by proliferation of cytomorphologically malignant oncocytic and adenocarcinomatous structural phenotype, including its infiltrative qualities. This tumor can occur de novo, but is usually found in association with a pre-existing oncocytoma. Gives metastases and recursively, is referred to as oncocytic carcinoma despite the absence of cellular signs of malignancy. The code is 8290/3.

Macroscopically, the cancer of the salivary gland has a dense consistency, homogeneous, devoid of capsules, on the cut - from gray to brown and reddish-brown sometimes with necrosis

Histologically the oncocytic cancer of the salivary gland is foci, islets and nests of large round or polygonal cells with a delicate granular oxyphilic cytoplasm and a rounded central nucleus, often with a pronounced nucleolus. Sometimes there are multi-nuclear cells. In some tumors, ductal structures of different caliber can occur. Tumor cells form layers, columnar formations, trabeculae and, in addition, glandular and pseudo-ferrous fields. The hyaline stroma of the tumor is infiltrated by oxyphilic granular cells. Oncocytic cancer of the salivary gland does not have a capsule and often infiltrates the adjacent muscle, lymph vessels and nerves. Characteristic are cellular and nuclear atypia, polymorphism. Tumor cells capture perineural structures, infiltrate tissues, skeletal muscles and vessels. They have little keratinization or mucin production PAS-reaction and reaction with alcian-blue are negative.

Ultrastructural studies conducted by Lee and Roth (1976) showed that the structure of a malignant oncocytoma does not differ from that of a benign tumor variant. Only there is no basal membrane and sometimes intercellular spaces are widened. The diagnosis of malignant oncocytoma is based on the presence of a defect in encapsulation, local, perineural and vascular invasion, regional and distant metastases.

The oncocytic nature of cells can be determined by various histochemical coloring methods that detect mitochondria, and also use an immunohistochemical method with antimitochondrial antibodies.

Immunohistochemical method helps distinguish oncocytic carcinoma from a benign oncocytoma. Antibodies K-67, alpha-1-antitrypsin are used.

Electron microscopy reveals a large number of mitochondria, often having an abnormal shape and size. Vnugricitoplasmatic lumens are lined with microvilli, and lipid drops are also found. Other ultrastructural features include an almost continuous basal plate of uniformly located desmosomes and a disruption of the arrangement of cristae in the mitochondria.

Prognostically cancerous cancer of the salivary gland belongs to high-grade tumors. It is characterized by multiple local recurrences, the presence of regional and distant metastases. Apparently, the most significant prognostic factor is the presence or absence of distant metastases.

Myoepithelial cancer of the salivary gland

A tumor consisting almost exclusively of tumor cells with myoepithelial differentiation, characterized by infiltrative growth and the ability to metastasize. This tumor is a malignant analogue of myoepithelioma. The code is 8982/3.

Synonym: malignant myoepithelioma.

Macroscopically myoepithelial cancer of the salivary gland is devoid of capsules, but can grow in a node and have very clear boundaries. The size of the tumor varies widely - from 2 to 10 cm. The surface of the tumor on the cut has a grayish-whitish color, it can be shiny. In some tumors, there are fields of necrosis and cystic degeneration.

Concerning the spread of myoepithelial carcinoma, it should be said that the tumor can affect the adjacent bone. There is a perineural and vascular invasion. Regional and distant metastases occur infrequently, but may manifest later, with the course of the disease.

Histologically, the myoepithelial cancer of the salivary gland is characterized by a multi-lobed structure. The type of myoepithelial carcinoma cells reflects its benign analogue, which occurs in myoepithelioma. Tumor cells are often fusiform, stellate, epithelioid, plasma-cytopoid (hyaline) or, occasionally, vacuolated by the type of cricoid cells. In other tumors, there is a tendency to increase the cellular component consisting of spindle-shaped cells resembling sarcoma. Very rarely, myoepithelial carcinoma consists of a monomorphic population of light cells with myoepithelial features.

Tumor cells can form solid or bundle structures, the type of structure can also be trabecular or reticular. But also tumor cells can be disconnected among themselves by an abundant myxoid or hyalineized stroma. Cystic or pseudocystic degeneration may occur. You can find small areas with squamous cell differentiation. Rarely myoepithelial cancer of the salivary gland contains ductal structures with lumens lined with non-luminal cells. A tumor consisting of a rather large number of duct structures lined with a large number of true luminal cells should not be included in the category of "pure" myoepithelial neoplasm.

Within the same tumor, different types of structure and various types of cells are found. Indeed, most myoepithelial carcinomas are less monomorphic than benign myoepithelioma. They can also be found to have increased mitotic activity. Cellular polymorphism is also noticeable, necrosis can be detected. Nevertheless, the main requirement for establishing a diagnosis is the detection of signs of infiltrative and destructive growth, and this is exactly the property that distinguishes myoepithelial carcinoma from a benign myoepithelial tumor.

It is believed that myoepithelial cancer of the salivary gland may occur de novo, but it should be emphasized that in half of cases it develops from a previous pleomorphic adenoma or benign myoepithelioma, especially from a recurrent one.

Genetic studies have revealed infrequent disorders in this tumor - approximately 25% of cases, mainly in the form of various chromosomal aberrations. Most often there are changes in the 8th chromosome.

Myoepithelial cancer of the salivary gland is a tumor with an aggressive growth pattern, and the clinical results of its treatment are different. Approximately 1/3 of patients die from this disease, another third suffer from tumor recurrences, often repeated, and, finally, another third - are completely cured. The pronounced cellular polymorphism and high proliferative activity correlate with poor prognosis. There is no difference in the clinical behavior of myoepithelial carcinoma growing de novo and those that develop from pleomorphic adenomas and benign myoepitheliomas.

Molecular genetic methods show chromosomal abnormalities in myoepithelial carcinomas in 20-25% of cases, more often related to changes in the 8th chromosome.

Salivary gland cancer from pleomorphic adenoma

Defined by the current classification of WHO as "pleomorphic adenoma from which a malignant tumor". The code is 8941/3.

Synonyms: salivary gland cancer from a benign mixed tumor, cancer in pleomorphic adenoma, malignant mixed tumor.

Macroscopically, the salivary gland carcinoma has the appearance of a clearly delineated node, has a capsule, which in some places can be defective, infiltrated or destroyed by tumor masses. The average size of carcinoma from pleomorphic adenomas is usually twice that of its benign analog, varying, according to various data, from 1.5 to 25 cm. The tumor has no clear boundaries, signs of invasive growth can be expressed. Sometimes carcinoma from pleomorphic adenoma has clear boundaries, grows in form of the scar or looks completely encapsulated.

On the cut, the surface of the tumor is solid, resembling a mixed tumor, but there are foci of hemorrhage, cystic degeneration, and necrotic areas characteristic of a malignant tumor.

Histologically, salivary gland cancer has a picture of pleomorphic adenoma with components of the structure of various carcinomas. Plots of growth have the appearance of solid, glandular carcinoma or epidermoid cancer, but most often it is necessary to differentiate it with adenocarcinoma and scaly carcinoma. In some places, the salivary gland cancer is differentiated as a squamous epithelium, taking a picture of primary mucoepidermoid cancer of medium and high degree of malignancy. In addition, glandular carcinoma tends to form papillary, cystic or trabecular structures.

Malignant transformation of pleomorphic adenoma is characterized by the appearance of hyperchromatic, cytologically distinct epithelial cells in the hyaline stroma. Cells infiltrate and destroy the structure of pleomorphic adenoma, capturing nerves and vessels. In some places, the tumor has a benign character, but cellular polymorphism and mitosis in other areas indicate a malignant character.

In some cases, the myxoid substance predominates, the chondroid nests consist of large hyperchromic chondroblasts mixed with the epithelial component of pleomorphic adenoma in various proportions. Chondroid and myxoid zones can be mistakenly regarded as elements of adenocarcinoma. There are areas of necrosis, hemorrhages and calcifications.

In some areas, spindle-shaped cells with an elongated nucleus and usually a scarce cytoplasm are visible in the stroma. Spindle-shaped cells are located diffusely or mixed with giant cells, forming pseudosarcomatous areas.

Histologically, the ratio of the benign and malignant components in the tumor differs significantly from case to case. Sometimes it is necessary to thoroughly study all the material in order to find a benign component, which in some cases can not be detected at all. However, if there is documented evidence of the presence in the same place of a surgically deleted pleomorphic adenoma, the tumor should still be classified as a carmine of pleomorphic adenoma.

The malignant component of carcinoma from pleomorphic adenoma is most often represented by a low-grade adenocarcinoma (such as SSC or RSD) or undifferentiated cancer. However, any form of SJ can be observed.

The most reliable diagnostic criterion is invasive and destructive tumor growth. Often there are nuclear atypia and hyperchromasia, but sometimes there are types of carcinoma from pleomorphic adenoma, in which atypia is minimal. This sign - atypia - determines the "grade" of the tumor and most significantly affects the prognosis. Usually there are fields of necrosis and mitoses are also easily detected.

Salivary gland cancer from pleomorphic adenoma should be divided into non-invasive, minimally invasive (less than 1.5 mm invasion of "extracapsular" tissue), invasive (more than 1.5 mm of tumor invasion into surrounding tissues). 

The first two groups have a very good forecast, while the third is very doubtful. Differences between invasive and non-invasive carcinoma from pleomorphic adenoma are based on the detection of signs of tumor invasion into surrounding tissues.

Undifferentiated cancer of the salivary gland in the morphological representation is a malignant epithelial tumor from rounded or spindle-shaped cells, which can not be assigned to any of the groups of SJ tumors. This cancer of the salivary gland does not have any structures and signs of functional differentiation. Microscopically isolated subtypes of cancer, depending on the type of cells. Currently, subtypes of undifferentiated cancer are considered as separate species.

Salivary gland cancer consists of round, small or medium-sized anaplastic cells forming layers or nests, separated by a fibrous hyaline stroma. There are round, uniform cells freely lying in the stroma, resembling a malignant lymphoma or reticulosarcoma. This is the so-called solid globular cell carcinoma of the salivary gland.

The spindle-like type of tumor is represented by small or medium-sized spindle-shaped cells, grouped or in rows, which are further intertwined with each other. Sometimes there are giant cells. The tumor resembles a spindle cell sarcoma or an embryonic myomatous tissue, but the cells are capable of differentiation. There are mitoses, zones of necrosis. Stroma is meager and usually hyaline. This tumor variant may resemble the small cell carcinoma described by Koos et al. In 1972

Polymorphic cell carcinoma of the salivary gland consists of anaplastic cells of various sizes and shapes diffusely scattered throughout the area of the lesion. The tumor stroma is loose, hyaline. Tumor cells infiltrate tissues, spreading to neighboring structures, penetrating into vessels and perineural spaces.

Lymphoepithelial cancer of the salivary gland

Undifferentiated cancer of the salivary gland, accompanied by pronounced non-tumorous lymphoplasmocytic infiltrates. The code is 8082/3.

Synonyms: lymphoepithelial-like salivary gland cancer, malignant lymphoepithelial tumor, undifferentiated cancer with lymphoid stroma, undifferentiated cancer, cancer from lymphoepithelial tumor.

As a variant of undifferentiated cancer, some are considered a malignant analog of benign lymphoepithelial lesions, others are considered as low-grade squamous cell carcinoma with a lymphoid stroma.

Macroscopically the cancer of the salivary gland can be clearly delineated or have pronounced signs of invasion into the surrounding tissue of the gland and adjacent to it soft tissues. The nodes of the tumor have a dense consistency and sizes from 1 to 10 cm (an average of 2-3 cm).

Histologically, the cancer of the salivary gland grows in the form of infiltrative foci, bundles, islets separated by a lymphoid stroma. Tumor cells have fuzzy boundaries, a light oxyphilic cytoplasm and an oval vesicular nucleus with a well-marked nucleolus. Nuclei usually moderately vary in size, although in rare cases they are completely monomorphic. Usually, necrosis fields and many mitotic figures are easily detected. Sometimes tumor cells have a "plump" and fusiform form and form a characteristic type of fascicle. Sometimes there are focuses of squamous cell differentiation in the form of an increase in the volume of the oxyphilic cytoplasm of tumor cells and the appearance of indistinctly expressed intercellular bridges.

The cancer of the salivary gland is densely infiltrated by lymphocytes and plasma cells, often with the formation of reactive lymphoid follicles. The lymphoid component can be so pronounced that it masks the epithelial nature of the tumor. In some cases, histiocytes are found in large numbers in tumor islets, creating a picture of the so-called "starry sky." Other non-permanent signs include: the formation of "noncaseating" granulomas with or without giant multinucleated cells, amyloid deposits, the formation of cysts in the islets of some tumors, perineural or lymphovascular invasion.

Tumor cells are immunoreactive for pancitokeratin and EMA. Lymphoid cells are represented by a mixture of T and B cells. Electron microscopy reveals signs of squamous cell differentiation in the form of desmosomes and tonofilaments.

In tumor cells, using the FISH or CISH methods, viral RNA and DNA belonging to the Epstein-Barr virus can be detected. The immunohistochemical determination of the membrane protein 1 of the Epstein-Barr virus is more variable.

Differential diagnosis of salivary gland cancer is carried out with metastasis of undifferentiated cancer, malignant lymphoma, lymphoepithelial sialadenitis, lymphadenoma, and also large-cell undifferentiated cancer. With lymphoepithelial sialoadenitis there is no pronounced cellular atypia, there is a basal membrane, there is no desmoppastic stroma reaction, there is no connection with the infection caused by the Epstein-Barr virus. For lymphadenoma is characterized by a more or less pronounced formation of glandular structures, there is no cellular atypia, there is no desmopastic stroma and connection with infection caused by the Epstein-Barr virus. Most lymphoepithelial carcinomas grow de novo, but sometimes they can develop in lymphoepithelial sialadenitis (formerly called myoepithelial sialadenitis). Reported a family predisposition to lymphoepithelial carcinoma of the SC with dominantly inherited trichoepithelioma, which, presumably, is associated with common suppressor genes.

Lymphoepithelial carcinoma

A rare tumor that accounts for less than 1% of all SJ tumors. There is a racial predisposition to the disease: the Eskimos are more often afflicted in the arctic regions (Greenland, Canada, Alaska), southeast Chinese and Japanese. The Inuit Inuit tribe has the highest incidence of SJ tumors in the world, most of which are represented by lymphoepithelial carcinoma. The mild predominance of women, the frequent involvement of the parotid gland, the more frequent observation of advanced stages of the disease and probably the more aggressive clinical course of the disease are all noted in the Inuit. The age of patients with lymphoepithelial carcinoma lies in a wide range - 10-90 years, the most frequently affected persons are 40-50 years old.

Etiologically, the salivary gland carcinoma in almost 100% of cases has a link between the lymphoepithelial carcinoma of the SLE and the Epstein-Barr virus in endemic areas, which suggests an important role for this virus in oncogenesis. The serological test reveals elevated titers of antibodies to the capsid and / or nuclear antigen of the Epstein-Barr virus in more than 50% of patients with lymphoepithelial carcinoma in endemic areas. In patients from non-endemic areas, the Epstein-Barr virus is found in rare cases. These data point to a whole complex of interactions of ethnic, geographical and viral factors in the pathogenesis of lymphoepithelial carcinoma of the SC.

Localization of lymphoepithelial carcinoma in 80% of cases is associated with parotid SLE followed by submandibular SJ. Occasionally, lymphoepithelial carcinoma occurs in the small SC of the oral cavity and the oropharynx.

Clinically, lymphoepithelial carcinoma is an increase in the parotid and submandibular SC, which often lasts for a long time, but with a sudden rapid growth. Pain may be absent. In advanced stages, the tumor can be soldered to surrounding tissues or skin. The defeat of the facial nerve occurs in no more than 20% of cases. Metastases in the lymph nodes are observed in 10-40% of cases. There are no clinical or serological data confirming the association of the disease with Sjogren's syndrome.

Since lymphoepithelial cancer of the salivary gland is morphologically not distinguishable from nasopharyngeal cancer (which occurs much more often), it is also important to take and examine a nasopharyngeal biopsy before establishing the primary nature of the tumor as a lymphoepithelial carcinoma of the SC.

Lymphoepithelial cancer of the salivary gland has a tendency to metastatically spread to regional lymph nodes. Approximately 20% of cases show distant metastases, among which localizations of lungs, liver, bones and brain are more common. The characteristic lymphopposmocytic infiltration, expressed in the primary tumor, may be weak or absent at all in metastasis.

Prognostically in patients with combined treatment (operation with radiotherapy), the 5-year survival rate reaches 75-86%, despite the possibility of local recurrence. The main and most significant prognostic factor is the stage of the disease. Attempts have been made to classify the "grade" of lymphoepithelial carcinoma depending on the number of mitoses and the degree of cellular polymorphism, but at the present time there is no such system of lymphoepithelial carcinoma subdivision by the degree of malignancy that would be generally accepted or at least widely spread.

Small cell carcinoma of the salivary gland

A rare cancer of the salivary gland, characterized by the proliferation of small anaplasied cells with scant cytoplasm, tender nuclear chromatin and invisible nucleoli. The code is 8041/3.

Synonyms: small-celled undifferentiated cancer of the salivary gland, small-cell anaplasmic cancer, ovarian cancer, neuroendocrine cancer.

Small cell carcinoma of the salivary gland is less than 1% of all tumors of the SJ and approximately 2% of the malignant tumors of the SLE. The age of most patients at the time of diagnosis is older than 50 years, but nevertheless, the tumor is also described in young people. Somewhat more often this lesion affects men.

The localization of the tumor is associated with large and small SJ and most often occurs in the parotid WH

Clinically, patients with cancer of the salivary gland complain of a painless, rapidly growing tumor for several months. Increased cervical lymph nodes and paralysis of facial muscles are frequent findings. Paraneoplastic syndrome, associated with the production of ectopic hormones, is not typical.

Macroscopically small cell carcinoma of the salivary gland is a dense tumor with fuzzy boundaries, often with signs of infiltration of the adjacent parenchyma of the SJ and adjacent soft tissues. A tumor usually has a grayish or whitish color, usually with areas of hemorrhage and necrosis.

Histologically small cell cancer of the salivary gland is characterized by bundles, irregularly shaped nests consisting of anaplastic cells and a different amount of fibrotic stroma. Nests of tumor cells can form palisade structures along the periphery of the tumor. Occasionally, rosette-like structures are seen. Tumor cells in size are usually 2-3 times larger than mature lymphocytes, and have a rounded or oval nucleus with scant cytoplasm. Sometimes there are single polygonal as well as large cells. Chromatin in the nuclei is tender, and the nucleoli are imperceptible or absent. The boundaries of the cells are poorly defined, and "stratification" of the nuclei is often observed on each other. Discover a lot of mitotic figures. A tumor can have small and rare foci of ductal differentiation. The focuses of squamous cell differentiation are also described. A frequent phenomenon is extensive fields of necrosis, hemorrhages, signs of perineural infestation.

Small cell carcinoma of the salivary gland as a whole has an unfavorable prognosis: local relapses and distant metastases occur in more than 50% of patients. Metastasis in the regional lymph nodes of the neck is observed less often than distant metastasis. The level of 5-year survival in small-cell carcinoma ranges from 13 to 46%, according to various authors. The survival rate is even lower in patients with a primary tumor, more than 3 cm in size, negative staining for cytokeratin 20, and reduced immunoreactivity to neuroendocrine markers.