Melanotic neurofibroma: a case report with ultrastructural study.

The authors report a case of a solitary melanotic neurofibroma involving the temporomalar area in a 17-year-old man. Light-microscopic study reveals a benign neurofibroma including melanin deposits. Electron microscopy shows typical premelanosomes and melanosomes within Schwann cell cytoplasm. The literature is reviewed, and theories of histogenesis for this unusual tumor are discussed.