Читать книгу Anterior Skull Base Tumors - Группа авторов - Страница 66

Primary melanoma in the sinonasal tract accounts for less than 1% of all melanomas [121–123]. They afflict patients in their 5th and 6th decades of life with equal gender distribution. The most frequently affected site is the lateral nasal wall, followed by the nasal septum, the maxillary antrum, and ethmoid. Symptoms are nasal obstruction and epistaxis, and the lesion presents as a polypoid nasal mass of a small to large size, with light-tan, brown, or black colourations. Histologically, the cytomorphologic features are comparable to those of melanoma of the skin: spindle, rounded, and epithelioid cells forming nests, sheets, and fascicles may be found [124–128]. These structures may contain melanin, but this is often absent. Mucosal involvement and epidermoid migration of melanocytic cells is a helpful diagnostic feature when present. Commonly, ancillary markers include HMB-45, Melan-A, MART-1, tyrosinase SOX10, and S-100.