Nevus of Oty and Ito: causes, symptoms, diagnosis, treatment

Nevus Ota is a site of hyperpigmentation of the skin, continuous or with small impregnations, from blue-black to dark brown, with a characteristic localization in the face in the zone of innervation of the trigeminal nerve. Can be two-sided. Usually, the conjunctiva of the eye is involved in the process on the side of the skin lesion.

Nevus Ito differs from other localization - on the skin in the supraclavicular and scapular region.

Pathomorphology. The histological picture of the nevuses Ota and Ito is similar to that of the blue nevus.

Histogenesis. In connection with the fact that among the cells of the blue nevus, many nerve fibers are detected by the silver impregnation method, some authors believe that this tumor is of a neural origin. Electron microscopy revealed melanosomes as in cells of a simple blue nevus. And in cells of the cellular blue nevus, and in neirolemocytes there are none.

Plexiform spindle cell nevus (blue deep penetrating nevus) develops usually at a young age, the preferred location is the scalp, cheeks. Area of the shoulder girdle. It is a symmetrical hyperpigmented papule or knobby element, not exceeding 1 cm in diameter.

Pathomorphology. Plexiform spindle cell nevus has histological signs that make it look like a combined nevus, cellular blue nevus and Spitz nevus. It is also characterized by large sizes and germination in the deep layers of the dermis and subcutaneous tissue. It is a clearly limited formation in the form of a triangle with a base facing the epidermis. As a rule, single nests of nonwoid melanocytosis are found in the epidermis. Distinctive features of the nevus are the presence in the dermis of narrow bundles and strands consisting of large pigmented (melkodispersny melanin) fusiform and epithelioid cells alternating with a large number of melanophages. Often there are smaller cells resembling the usual melanocytic nevus. Melatsitov with long processes and cells with a light cytoplasm, as in blue nevuses, no. There are clusters of nevomelanocytes around the appendages of the skin. There can be a significant polymorphism of nuclei of variable size and shape, with hyperchromasia and pseudo-switching. Mitoses are not characteristic. A slight lymphocytic reaction is possible. Neurotropism, as well as in the cellular blue nevi and Spitz nevi, is not a sign of malignancy.

Immunomorphological examination of nesyca cells gives a positive coloring on the antigens S-100 and HMB-45.

[1], [2], [3], [4]