Sinonasal mucosal malignant melanoma: report of an unusual case mimicking schwannoma.

Primary mucosal melanoma of the sinonasal tract is a rare malignancy that has a more aggressive clinical course than its cutaneous counterpart. The histology of these lesions varies, with differing degrees of melanin production and an epithelioid or spindle-cell growth pattern. Cutaneous melanocytic lesions may differentiate in accordance with their neural crest derivation and express morphology similar to nerve sheath tumors. We believe the following case study reports the first instance of a mucosal melanoma with a Schwannian pattern of growth, arising from the nasal cavity of a 26-year-old man.