111. Tumors of the anterior pituitary gland: origin, terminology, types. Macro-microscopic structure, complications, clinical significance.

According to the histological structure in the adenohypophysis, adenoma (dobrokach) is isolated by tinctorial properties: chromophobic, eosinophilic, basophilic by the nature of hormonal activity: hormonally active (somatotropic (eosinophilic), prolactin (chromophobic or eosinophilic), adenoma from cells secreting ACTH (chromophobic or basophilic), adenoma from cells secreting TSH (chromophobic or basophilic), an adenoma from cells secreting follicle-stimulating hormone (chromophobic))

Morphologically, there are chromophobic, eosinophilic and basophilic adenomas. They have hormonal activity and are accompanied by the development of a characteristic syndrome.

Hormone-active pituitary adenomas:

• somatotropic — eosinophilic adenoma;

• prolactin — chromophobic or eosinophilic adenoma;

• adenoma from ACTH—secreting cells - chromophobic or basophilic adenoma;

• adenoma from cells secreting thyroid—stimulating hormone - chromophobic or basophilic adenoma;

• adenoma from cells secreting follicle—stimulating hormone is a chromophobic adenoma; it is extremely rare (in eunuchs). Malignant analogues of pituitary adenomas — cancer

The manifestations of pituitary adenoma depend on the hormonal function of the tumor. With hormonally active adenomas, the main manifestations are specific hormonal disorders. With hormonally inactive adenomas, patients most often complain of visual impairment (most often narrowing of the fields and decreased visual acuity) and headaches. A rare manifestation of a large pituitary adenoma is a sharp attack of headache, a sharp narrowing of the fields and a drop in visual acuity, when a special part of the brain — the hypothalamus — is involved in the process of impaired consciousness.

From the outside, the eosinophilic adenoma is covered with a relatively dense connective tissue capsule and the tumor itself has an elastic consistency. In the section, this neoplasm is pinkish or grayish in hue, of a homogeneous structure. Microscopic examination shows that the tumor parenchyma consists mainly of dystrophically altered eosinophilic cells. In places, the main and chromophobic cells of the pituitary gland are also found.

In the chromophobic adenoma of the pituitary gland, cells containing a small number of granules with a relatively low electron density are detected. The endoplasmic reticulum is represented by separate membranes, among which ribosomes are freely located. Mitochondria are more often elongated in shape with longitudinal crystals, the nucleus has deep indentations. The restrictive cell membrane is wavy and forms numerous appendages.

Among fast-growing cells, foci of necrosis, multiple diffuse hemorrhages, and proliferation of glandular structures are often found.

112. Tumors of the thyroid gland: origin, terminology, types. Macro-microscopic structure, complications, clinical significance.

1. Adenoma

follicular (similar in structure to the thyroid gland - from follicles)- from A and B cells

solid - made of C-cells

papillary - cystic formations with branching papillary structures

2. Cancer

follicular

solid cancer with stroma amyloidosis (associated with C cells)

papillary

undifferentiated (randomly arranged cells of various sizes)

Each thyroid cell (A, B and C) can become a source of benign (adenoma) or malignant (cancer) tumors.

Follicular adenoma develops from A- and B-cells, approaches the thyroid gland in structure, consists of small (microfollicular) and larger (macrofollicular) follicles.

A solid adenoma originates from calcitonin-secreting C cells. The tumor cells are large, with a light oxyphilic cytoplasm, and grow among the follicles filled with colloid. A tumor with cystic formations and branching papillary structures is a papillary adenoma of the thyroid gland. Papillary structures in the adenoma are an unfavorable sign of possible malignancy. Thyroid cancer often develops from an adenoma.

• Follicular cancer occurs on the basis of follicular adenoma, consists of atypical follicular cells that grow into the capsule and vascular walls. Hematogenous bone metastases often occur. One of the variants of the tumor is the proliferating Langhans struma, in which there is no pronounced cellular atypism, but a tendency to infiltrating growth and metastasis appears. Follicular cancer from A-cells has a relatively favorable course and prognosis, metastases occur in the later stages of the disease. Cancer from B cells proceeds slowly, but its prognosis is less favorable, since metastases to the lungs and bones appear early.

• Papillary cancer ranks first among malignant tumors of the thyroid gland in frequency, consists of different cavities lined with atypical epithelium and filled with papillae emanating from the cyst wall; in places, papillae grow into the wall of cavities and the tumor capsule. One of the types of papillary cancer that develops from A-cells is a sclerosing microcarcinoma, or microcarcinoma in the scar, detected accidentally by microscopic examination.

• Solid (medullary) cancer with stroma amyloidosis is histogenetically associated with C cells, which is confirmed by the presence of calcitonin in the tumor and the similarity of the ultrastructure of tumor cells with C cells. In the stroma of the tumor, an amyloid is detected, which is formed by tumor cells— APUD-amyloid.

Undifferentiated cancer develops mainly in the elderly, more often in women. It is built of nests and randomly arranged cells of different sizes, sometimes very small (small cell carcinoma) or giant (giant cell carcinoma).

In the vast majority of cases, the tumor process is completely asymptomatic and is detected accidentally in the form of a node in the thyroid gland during ultrasound examination and less often during a doctor's examination or independently. The function of the thyroid gland is almost always preserved. Possible symptoms of thyroid cancer include: - the appearance of a formation in the lower third of the neck or an increase in the lymph nodes of the neck; - a change in voice, hoarseness of voice; - difficulty breathing; - the appearance of pain in the lower third of the neck or chest.

More than 90% of patients diagnosed with thyroid cancer can be completely cured with proper management.