Desmoplastic melanoma.

Desmoplastic melanoma is an uncommon type of malignant melanoma that has a predilection for the skin of the head and neck. Because of a progressive metaplasia of melanocytes and an accompanying desmoplasia, the neoplasm can be mistaken for benign or malignant soft tissue lesions. The neurotropism exhibited by many desmoplastic melanomas is a strong adverse factor for prognosis; otherwise, the biologic behavior is not unlike that of conventional melanomas.