Case of the month: diagnostic challenges from your case files

CASE The patient is an 80-year-old white man who was referred by his primary care physician to the orthopedic surgery clinic at the end of December 2003 for evaluation and treatment of his right thumbnail, which was splitting and discolored. ALM arises subungually or periungually, typically manifests as pigmentation and/or nail plate dystrophy, and accounts for 2% to 3% of melanomas in white persons aged 55 to 60 years.2 Common sites involve the thumb and great toe.