A 61-year-old white man presented with a 2-year history of linear pigmentation involving his third right fingernail. There was no history of trauma. Physical examination revealed that approximately 90% of the nail plate was involved, with several 0.5- to 2.0-mm homogeneous, brown-black, longitudinal, pigmented streaks and intervening red hues (Figure 1). There were no palpable nail plate changes. Periungual pigmentation was not evident. Lymphadenopathy was not present, and there was no other significant physical finding.

A biopsy of the proximal nail matrix (Figure 2 and Figure 3) was performed via 2 tangential 3-mm incisions laterally and proximally by bisecting the proximal and lateral nail folds. Skin hooks were then used to re-tract and completely expose the proximal nail matrix, where a 4-mm punch biopsy specimen was obtained. The skin flaps were then secured into place with two 4-0 nylon sutures.