Zlokachestvennaya melanoma (melanoma, melanokarcinoma, nevokarcinoma)

It is characterized by rapid growth of malignant, early metastasizes, It is one of the most human cancers. It may develop from nevi, or appears on the external intact skin. For melanoma tumor progression characteristic early dissemination. There are three types of melanoma:

• Surface-propagating;
• Type malignant lentigo;
• Uzlovuû.

Before puberty, melanoma is almost never. Grossly the tumor can have a different shape. In the early stages it is slightly protruding plaque or nodule, surrounded by an erythematous area. The intensity of pigmentation varies. During the growth of the tumor may become ulcerated or fungoznoy. Melanoma often has no macroscopic signs of malignancy, despite the presence of multiple metastases. There are cases, when in the presence of metastases primary tumor was not detected. Development of Melanoma occurs primarily in the skin, at least - in the mucous membranes and other tissues.

Tsitologicheski melanoma It consists of epithelial-, spindle-shaped cells and nevusopodobnyh. The most common epithelioid cells, which have different shape, the size of the nucleus and cytoplasm. Sometimes this giant cells with an oval nucleus, containing different amounts of chromatin and hypertrophied nucleoli.

The cytoplasm of these cells wide, It contains a small amount of melanin granules of different sizes. Sometimes epithelioid cells of moderate size, oval.

Cores of hyperchromic, big. Many mitotic figures. The test material are also found cube-shaped or cylindrical cells, which can form glandular structures, In the absence of melanin leads to difficulties in their differentiation adenocarcinoma. Epithelioid melanoma cells may also have a spheroidal shape, contain light cytoplasm and multiple nuclei.

Spindle cell melanoma like fibroblasts and fibrocytes medium and large sizes.

Have a large oval, hyperchromatic nucleus, in some of them, lighter, nucleoli are found. There are multi-cell. With mild polymorphism spindle melanoma cells essential for diagnosis is found in the cytoplasm of melanin.

To nevusokletochnoy melanoma characterized by detection of cells in cytological preparations medium sized round, or irregular polygonal shape. The nuclei of large, normo- or more hyperchromic, round or oval, contain one, less two nucleoli. There are cells with two or three cores. The cytoplasm of moderate width, basophilic, circumferentially oxyphilous. Grains of melanin contained in the tumor cells, and in macrophages.

It also occurs mixed cell melanoma.

Melanin content in different tumors. The pigment can be deposited in the form of large grains, that fill the cell completely and paint it in the dark. Sometimes gentle grain dusts, scattered diffusely in the cytoplasm. Melanin may be located extracellularly and.

Amelanotic (amelanoticheskaya) melanoma rare. In these cases, malignancy is confined to the establishment of the cells.

Epithelioid melanoma more sensitive to treatment, than fusiform. The possibility of spontaneous regression of melanoma, wherein the color changes to blue tumor, gray or white. When resorption tumor remains depigmented skin area.