107. Benign epithelial tumors: terminology, localization. Macro- and microscopic features of the structure, the nature of growth, outcomes, complications, clinical significance.

Benign epitheliomas include: Papilloma, Adenoma.

Papilloma is a benign tumor of a multilayer flat or transitional epithelium. It often occurs in the skin, larynx, mouth, esophagus, bladder, kidney pelvis, ureter, vagina, etc. Sometimes papilloma can be multiple (laryngeal papillomatosis). In rare cases, papilloma recurs and becomes malignified (larynx, bladder), therefore it is of great clinical importance.

Macroscopic picture:  Spherical mobile formation on a wide base or thin stem,  Of a mildly elastic consistency,  The surface is covered with small papillae ("cauliflower").

Microscopic picture: Papillary growths of a multilayer flat (or transitional) epithelium, which, like a glove, cover the connective tissue stroma containing blood vessels. The multilayer squamous epithelium lies on the basement membrane, retains its polarity and complexity. Uneven increase in epithelial layers, increased keratinization (tissue atypism).

Adenoma is a benign tumor of the prismatic and glandular epithelium. It is found on mucous membranes lined with prismatic epithelium and in glandular organs. Adenomas of the mucous membrane of the colon and stomach are often malignified.

Morphological variants of adenoma:

Alveolar adenoma is from the alveolar epithelium of the glands.

 Tubular adenoma – from the epithelium of the ducts of the glands.

Trabecular adenoma – has a girder structure.

Fibroadenoma is an adenoma in which the stroma predominates over the parenchyma.

An adenomatous (glandular) polyp is an adenoma of the mucous membranes protruding above the surface in the form of a polyp.

Cystic adenoma (cystadenoma) is an adenoma containing cavities.

108. Cancer: definition, localization, basic principles of classification. Macro- and microscopic structural features, growth patterns, metastasis, outcomes, complications, clinical significance.

Malignant epithelial tumors are called cancer, or carcinoma.

General characteristics:

They are much more common than all other malignant tumors.

They are often associated with previous diseases and conditions called precancerous.

The development of many carcinomas (morphogenesis) is associated with previous epithelial changes – hyperplasia, metaplasia, dysplasia.

Epithelial dysplasia is currently considered the only precancerous process, which, progressing from mild to moderate to severe, can lead to the development of carcinoma in situ and further invasive cancer that sprouts surrounding tissues

Invasive cancer is characterized by all the signs of a malignant tumor.

Cancer metastasizes mainly lymphogenously: the first metastases occur in regional lymph nodes, later hematogenous and implantation metastases may occur.

Classification of cancer

According to the histological structure:

 from the integumentary epithelium:

Squamous cell (epidermal) cancer,

Basal cell carcinoma,

Transitional cell carcinoma,

 Undifferentiated (small cell, large cell, etc.)

 from the glandular epithelium:

Adenocarcinoma (glandular cancer),

Solid cancer.

According to the ratio of parenchyma and stroma:

 Medullary (medullary) cancer,

 Simple (vulgar) cancer,

 Skirr (fibrotic cancer)

Squamous cell carcinoma. It develops from a multilayer flat epithelium in the skin, cervix, esophagus, larynx, etc. In the lungs, it occurs against the background of squamous cell metaplasia (epidermization) of the bronchial epithelium. It can be highly, moderately, and low-differentiated.

Basal cell carcinoma. It is characterized by the formation of polymorphic tumor epithelial complexes consisting of cells that resemble cells of the basal layer of the multilayer squamous epithelium. Cells are small, prismatic or polygonal in shape, with hyperchromic nuclei and a narrow rim of cytoplasm. The cells are arranged in a palisade perpendicular to the basement membrane, mitoses are not uncommon.  When localized on the skin, it grows slowly, often ulcerates with the formation of a deep ulcer. It is characterized by a slow course, pronounced destructive growth, and late metastases.

Transitional cell carcinoma. Highly differentiated cancer, according to the histological picture, is often very difficult to distinguish from transitional cell papilloma. A distinctive feature is the destruction of the basement membrane and infiltration by tumor cells of their own mucosal layer

Small cell carcinoma. A form of undifferentiated cancer that consists of monomorphic lymphocyte-like cells that do not form any structures. Stroma is small. There are many mitoses in the tumor, extensive areas of necrosis. It grows rapidly and is characterized by early and widespread metastasis.

Adenocarcinoma. It develops from the prismatic epithelium lining the mucous membranes, as well as from the glandular epithelium of various organs. It occurs in the urinary tract against the background of glandular tumor metaplasia. A characteristic microscopic feature is the presence of invasively growing glandular structures. Depending on the degree of differentiation, high-, moderate- and low-grade adenocarcinoma is isolated.

With a high degree of differentiation:  the cancerous epithelium forms glandular structures in which many cells resemble their normal counterparts (mild atypism), in the lumen of the cancerous glands there is a corresponding secretory product. With a low degree of differentiation, glandular complexes may look different:  If mucus secretion does not occur, then the number of these complexes per unit of the studied area increases, not the size. If the function of glandular structures is strongly developed, then they can greatly expand and overflow with mucus ("lakes of mucus"). This form of low-grade adenocarcinoma is called mucosal, or colloidal, cancer. There is a variant of low-grade adenocarcinoma in which there are no "lakes of mucus", but there are a lot of randomly arranged cancer cells filled with mucus, with the nucleus pushed back to the plasmolemma (cricoid cells). This variant is called cricoid cell carcinoma.

Solid cancer. One of the forms of glandular undifferentiated cancer. There are many massive layers of parenchyma in the tumor, and relatively few stromas.

Medullary cancer. It is characterized by the predominance of parenchyma over stroma. The tumor is soft, white-pink in color, resembles brain tissue.

Skirr (fibrotic cancer). One of the forms of low-grade cancer. Stroma prevails in the tumor, parenchyma is poorly represented. It occurs mainly in the stomach.

Ways of metastasis • In continuation, Lymphogenic (cancer, melanoma) - into lymphatic vessels, nodes, veins. Hematogenic - through the veins - into the lungs, . liver (portal vein), through the arteries of a large circle - to the brain, kidneys, liver, adrenal glands, bone marrow, skin. The prince of the system is implanted in the pujol - along the peritoneum, pleura, pericardium, membranes and ventricles of the brain