title: Neurothekeoma. Report of a case with immunohistochemical and ultrastructural studies.
abstract: A case of neurothekeoma in a 52-year-old woman is reported. The tumor developed on the medial aspect of the right nostril as a well-demarcated, dome-shaped, erythematous nodule of rubbery consistency. Microscopically, it consisted of numerous nests and cords of spindle-shaped cells in the dermis. Some of the tumor cell nests appeared epithelial-like, while the other areas showed a myxomatous appearence with various amount of mucinous matrix in the intercellular space. Neurothekeoma is a benign cutaneous tumor, and is considered to be of schwann cell origin. In the present case, the tumor cells did not stain positively for S-100 protein, despite the light microscopic suggestion of peripheral nerve origin. Ultrastructurally, most tumor cells contained a large number of myelinoid figures. This ultrastructural finding appears to be a useful diagnostic characteristics of neurothekeomas.
mesh_terms: D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D008854:Microscopy, Electron; D008875:Middle Aged; D009669:Nose Neoplasms / Q000473:pathology / Q000648:ultrastructure*; D012878:Skin Neoplasms / Q000473:pathology / Q000648:ultrastructure*