Desmoplastic Melanoma

Desmoplastic melanoma is an uncommonly encountered variant of malignant melanoma. Three histological subtypes exist: desmoplastic, neurotropic, and neural transforming. Desmoplastic melanoma commonly presents in conjunction with existing melanocytic lesions or as an amelanotic firm nodule. Local recurrences are common. Thirty patients over a 6-year period were treated at our institution for desmoplastic melanoma. All lesions were treated with local excision. Local recurrence occurred in seven patients (23%) and was treated by aggressive re-excision in each instance. Clinical regional metastasis (lymph nodal basins) were detected in two patients (6%). Distant metastasis (lung) developed in two patients (6%). Twenty-three patients (76%) were found to have desmoplastic subtype, whereas five (17%) had neurotropic subtype. Six patients (20%) had associated pigmented melanotic lesions. Average length of follow-up has been 18 months. Overall survival is 96 per cent. Presentations and histologic diagnosis can sometimes be difficult and misleading. Treatment is aggressive local excision with follow-up necessary to detect resectable recurrent lesions.