Desmoplastic melanoma: patterns of recurrence

Desmoplastic melanoma is a rare type of malignant melanoma, recognized since 1971. Other variants of desmoplastic melanoma include neural transforming melanoma and neurotropic melanoma. The pathology and clinical features of 58 patients whose tumor had the features of desmoplastic melanoma, neural transforming melanoma, and neurotropic melanoma, either separately or in combination, were examined to assess patterns of recurrent disease. The tumor was situated on the head and neck in 41% of patients and was amelanotic in 71% of patients. There was an associated superficial melanoma in 48% of patients. There was a combination of the 3 histologic patterns, commonly found in the 1 melanoma. Local recurrence occurred in 29% of patients and malignant cranial neuropathies were documented in 4 patients. Nineteen percent of patients have died from disseminated disease. Neurotropic melanomas had a lower incidence of visceral recurrence. Desmoplastic and neural transforming melanomas had similar rates of local and visceral recurrence. When this specific variant of melanoma is compared with larger series of malignant melanoma in general, they appear to be more advanced locally, with a higher incidence of local recurrence. When considered in relation to the thicker nondesmoplastic melanomas, the survival is no worse and may be more favorable. Surgeons should excise the primary tumor and local recurrences with wide margins and adopt close follow-up. On the head and neck, symptoms and signs relating to trigeminal or facial nerve innervation may herald a developing malignant cranial neuropathy.