A seemingly healthy 71-year-old white man had an 18-month history of a slow-growing lesion on his right index finger. He reported that a small reddish nodular lesion had initially appeared on the edge of the nail bed and had doubled in size within a few months. The lesion was neither painful nor symptomatic. His general practitioner diagnosed a pyogenic granuloma that he treated with electrocoagulation without requesting a histologic examination of the lesion. However, just 1 month after the lesion had healed the patient noticed that it was reappearing slightly enlarged and that it was beginning to modify the nail plate. This time, his physician referred him to a dermatologist who confirmed the original diagnosis of pyogenic granuloma and treated the lesion again with electrocoagulation, still without performing a histologic examination. Within a few weeks the lesion reappeared again, gradually increased, and destroyed the nail plate. After a few months, the patient was referred to our clinic for evaluation.
de Giorgi V, Stante M, Carelli G, Carli P. Subungual Melanoma: An Insidious Erythematous Nodule on the Nail Bed. Arch Dermatol. 2005;141(3):398–399. doi:10.1001/archderm.141.3.398