Malignant schwannoma with melanocytic differentiation arising in a patient with neurofibromatosis.

A 50-year-old woman with von Recklinghausen's disease, but not Carney's complex, presented with a 1-year history of a hard subcutaneous mass on her right hip and right inguinal lymphadenopathy. Histological and immunohistochemical studies of the tumour revealed schwannian and melanocytic characteristics. Local recurrence without distant metastases was observed 5 years later. Although the diagnosis of malignant schwannoma with melanocytic differentiation, rather than neurotropic melanoma, was made for the primary tumour, based on the clinicohistopathological and ultrastructural findings, the overall clinical course in this case did not seem incompatible with malignant melanocytic schwannoma.