Subungual nail bed melanoma masquerading as tinea ungium

Subungual amelanotic melanoma can masquerade as onychomycosis. Recently a man whose amelanotic nail bed melanoma presented as persistent onychodystrophy was reported in the Dermatology Online Journal. The patient had a persistent nail dystrophy; culture and biopsy of the nail demonstrated Candida and dermatophyte infection, respectively. However, he subsequently presented with a nodule that was biopsied and demonstrated melanoma. Similar to that patient, we recently described a 67-year-old woman with a four-year history of persistent nail dystrophy of the left fourth fingernail who had a periodic acid-Schiff staining of the nail plate demonstrating fungal hyphae. Her nail plate subsequently detached, demonstrating a friable nodule; a biopsy of the nodule demonstrated melanoma. In conclusion, in individuals with new morphologic changes to a dystrophic nail or with persistent nail dystrophy despite appropriate therapy, it is important for clinicians to consider performing additional evaluation and possible biopsy to exclude malignancy.