NEUROTROPIC MELANOMA - VARIANT OF DESMOPLASTIC MELANOMA

We report a group of neuroid, cutaneous tumors that are usually associated with, or preceded by a melanocytic dysplasia. For this clinicopathologic entity we have chosen the term neurotropic melanoma. The neurotropic melanoma is a cutaneous fibrous tumor whose clinical course is characterized by local infiltration, multiple recurrences, and commonly by metastases. Its microscopic picture is characterized by atypical 'neuroma-like' patterns, by poorly defined margins, and by neurotropism. Its early or precursory melanocytic dysplasias include lentigo maligna (actinic or lentigo maligna variant), and a melanoma with borderline cytologic characteristics (minimal deviation variant). A third type is not preceded by a recognizable melanocytic dysplasia: it has 'neuroma-like' qualities at its inception (de novo variant). In the 22 cases reported, the preponderant sites were the head, neck, and lip. The patients were fair-faced, and 18 of the patients were over 40 years old. Seventeen patients had one or more recurrences. Of 16 patients with follow-up, nine died with evidence of disease, five are alive with active disease, and seven are apparently free of disease.