Edema of muscle tissue
Tumors of muscle tissue. Leiomyoma.
Tumors of muscle tissue are divided into smooth muscle tumors - leiomyomas andtransversely striated - rhabdomyomas with their malignant analogs of malignant leiomyomas and malignant rhabdomyomas. The so-called myoma of myoblasts (Abrikosov's tumor, myoblastomyoma) and epithelioid leiomyoma, whose histogenesis remains unclear, stand apart. The source of smooth muscle cells in soft tissues are the walls of the vessels and perivascular cambial elements that can differentiate into smooth muscle. The transverse striated muscles are mesodermal and arise from myotomes. It is also suggested that the muscles of the ventral part of the trunk and extremities are formed from the mesenchyme.
Leiomyoma (fibroleiomyoma, myoma, vascular leiomyoma) -mature benign tumor. Occurs in any age in people of both sexes, often in 30-50 years. Microscopically, the tumor is a clearly delimited knot of dense consistency. Sizes are very different. In zabryu-bus fiber, mediastinum, lung, its diameter can be more than 15-20 cm. Often, leiomyomas are multiple, sometimes as isolated, then in the form of merging nodes. Microscopically, the leiomyoma consists of spindle-shaped muscular muscle cells that collect in bundles going in different directions. The cells are surrounded by argyrophilic fibers, forming a case for each of them. Collagen fibers are found in small quantities.
Tumor muscular cells differ from the normal somewhat largersize, denser nucleus. In the cytoplasm of mogio, myofibrils can be detected. Especially when staining with iron hematoxylin according to Heidenheim, azan according to Mallory, an oino is clearly detected during electron microscopic examination. On the cross sections, the nuclei are rounded, lying in the center of the cell body. With such cross-sections, the structure of the argyrophilic network, whose loops surround each cell, is particularly well visible. Most clearly, the structure of the leiomyomus appears in the Van Gieson coloration, Mallory's azan, when impregnating with silver by the Pope or Futa. Sometimes the nuclei in the myomium form the so-called rhythmic structures or figures of the palisade, which serves as an indicator of tumor growth.
Microstructure of myoma varies depending on her age. On the border of the tumor with surrounding tissues, the reactive changes are poorly expressed, and the tumor is not clearly delineated, which creates a false impression of infiltrating growth. Over time, the amount of stroma increases, the muscle cells atrophy, resulting in the tumor gradually acquires the structure of fibroids and turns into a clearly delimited node. Stroma with myomas and especially the walls of the vessels undergo hyalinosis. As an expression of dystrophic processes and involutional changes, pycnosis of the nuclei of muscle cells, the appearance of their ugly forms, the vacuolization of the cytoplasm are possible. This creates a picture of the polymorphism of the tumor structure, the cause of which, therefore, lies in degenerative changes.
It must be distinguished from polymorphism. associated with further cataplasia and possiblemalignant tumor. In myomas, disturbances of circulation often lead to edema and necrobiosis of the tissue, followed by the formation of foci of necrosis and cysts. At the periphery of such foci, the proliferation of tumor cells and its stromal elements with polymorphism of cellular structures is intensified, which can also create a false image of the malignancy of the tumor. It is usually not difficult to distinguish leiomyoma from fibroma and fibrosarcoma, especially if staining sections by Vai-Gizon, Futu or Papa. Differential diagnostics with neurogenic tumors and especially with fascicular neurilemoma is more difficult.
The main criteria serve the form of nuclei and the ratio of cells to fibersstroma, as well as electron microscopy data. It is noted that the presence or absence of malignant leiomyoma is often difficult to determine, as the criteria for malignancy of this tumor are relative and insufficient, and their significance is different for different tumor localizations.
Angioleiomyoma from the terminal arteries (angiomyoma, vascular leiomyoma) for the first timewas isolated by V Babes as far back as 1884, was studied in detail by AR Stout, R. W. Allen, S. Schumacher and others in the 40-50s of the 20th century. Clinically characterized by soreness under external influences (pressure and m) irritation and emotion may change in size (tumor erectilis). The size of the tumor rarely exceeds 1-2.5 cm, is located under the skin, the bowl on the lower limbs, mainly in the elderly, mostly (up to 2/3 of all observations) is localized near the joints. Characterized by slow growth and benign course.
Microscopically characterized by an abundance of blood vessels different structures, among whichArteries, in structure close to the arteries of the closing type. These arteries have a star-shaped lumen, and their walls are built of several layers of smooth muscles, among which there are longitudinal muscular and outer annular layers. Under the layer of the endothelium, it is often possible to see clusters of epithelioid cells resembling glomus cells. The arteries in the tumor form irregularly wriggling and folding vessels. Along with such vessels in the tumor there are vessels of sinusoidal tissue and vessels resembling veins. The stromal elements between all these formations are unevenly expressed, the stroma is scant, it is represented by collagenous, partly hyalineized fibers and their bundles. Muscle cells are enclosed in a delicate argyrophilic network, the fibers of which are braided by each such cell. Occasionally you can see hemorrhages, accumulations of hemosiderin grains, small foci of tissue necrosis.
The tumor has clear contours. sometimes associated with the wall of a large artery.
Depending on the predominance of these or other structural elements, angioleiomyoma arterial, venous, mixed type or malodifferentiated tumors with a few slick-like vascular formations.
Genes with angiolemia is debated, the point of view about their proximity to the Barre-Masson glomusangiomas prevails at the present time.