Malignant melanoma of the sinonasal mucosa: two case reports and a review.

Malignant melanoma of the sinonasal cavity is an uncommon disease, and therefore a limited amount of data exists regarding its optimal treatment. The course of the disease is highly variable. Individual survival is also highly variable, but the overall prognosis is poor; probably because patients generally present at a late stage and because the disease has a proclivity for distant dissemination.