A Case of Pigmented Longitudinal Melanonychia

A man in his 40s presented to the dermatology clinic for evaluation of a dark brown longitudinal pigment band covering his left second toenail; the lesion appeared 12 months prior, had been growing, and was asymptomatic. What is your diagnosis?

Source: JAMA Dermatology - August 15, 2018 Category: Dermatology Source Type: research