Nevus Spitz: causes, symptoms, diagnosis, treatment

Nevus Spitz (syn: spindle cell and / or elithelioid-cell nevus, juvenile melanoma) is an unusual non-moloal melanocyte neoplasm that has a clinical and morphological similarity to the malignant melanoma of the skin. The question of inheritance is not settled. Can be congenital. It occurs with a frequency independent of sex. There are information about family cases.

It develops mainly in children. Clinically, the nevus is usually an asymptomatic tumor-like formation, hemispherical or planar, with clear boundaries. Dimensions are usually small, less than 1 cm, the color varies from light red to dark brown and even black. The consistency of the nevus is soft-elastic or dense. Surface - smooth, hairless, less often hyperkeratotic, warty. In rare cases, bleeding may occur, ulceration. Initially, the tumor grows rapidly, and then for many years can remain in a steady state. Possible cases with multiple, usually grouped nevi - from 20 to 50 elements. Localization of the nevus, according to research, depends on its clinical and morphological type. So. Flat hyperpigmented variants are more often localized on limbs, and pigmentless formations of red color are commonly found on the face and scalp.

Pathomorphology. Histologically, the nevus can be borderline. Mixed and intradermal. The most common is sour cream. In most cases, both fusiform and epithelial cells are defined, but the nevus can consist only of epithelioid, hack, and only of spindle-shaped cells. The pigment content of nevomelanocytes is variable. Often expressed atypism and polymorphism of cellular elements, in the nuclei of a part of cells pseudocolons (invagination of the cytoplasm) are detected.

The characteristic features of the nevus are: symmetrical structure of the nevus (in the horizontal plane): clear lateral borders with a predominance of non-vest nests along the periphery, and not isolated melanocytosis; The nests of melanocytes in the epidermis tend to merge with each other, surrounded by artifact slits; decrease in the size of cells in the lower parts of the dermis as compared to the overlying ones: the presence of eosinophilic Kamino chambers in the epidermis or the upper part of the dermis; edema and telangiectasia in the upper part of the dermis. It is possible to have a poorly regulated migration of melanocytes into the suprabasal layers of the epidermis. Mitoses are only superficial, usually no more than one in the field of vision at high magnification.

A special option is Reed's pigmented spindle cell nevus. As a rule, it is located superficially - in the epidermis and papillary layer of the dermis, characterized by the presence of exclusively spindle-shaped cells, a significant pigment content, is often accompanied by atypical cellular elements.

In the case of nmunomorphology, nevi cells are positively stained for vimentin and S-100 antigen, and variably for NMW-45.