A Diagnostic Challenge: Desmoplastic Melanoma

Desmoplastic melanoma (DM) is uncommon and can be a diagnostic challenge both clinically and histologically. We report a unique presentation of DM presenting as an amelanotic, depressed, indurated plaque on the forehead. The lesion was clinically concerning for a morpheaform basal cell carcinoma and with an unrevealing initial punch biopsy, an excisional biopsy with immunohistochemistry was necessary to determine a diagnosis of pure desmoplastic melanoma. When a patient presents with a depressed, indurated plaque of unknown etiology, including DM in the clinical differential diagnosis and communicating this to the dermatopathologist can potentially reduce the risk for a delay in diagnosis.