Malignant melanoma simulating schwannian differentiation.

A malignant melanoma demonstrating palisades of spindled melanocytes strikingly similar to Verocay bodies is reported. Immunohistochemical staining for S-100 protein and neuron-specific enolase revealed uniform positive staining of the neoplastic cells consistent with malignant melanoma. Immunohistochemical staining for myelin basic protein, a marker specific for Schwann cells, was negative in neoplastic cells. Ultrastructural examination revealed numerous melanosomes, confirming the melanocytic nature of this neoplasm. The differential diagnosis and possible histogenesis of this neoplasm are discussed.