Subungual leukemia cutis.

A 79-year-old man had generalized humping of the nails and subungual tumors involving several fingers and the left big toe. Findings on histologic study of the tumor, together with the pattern on the peripheral blood smear, established the diagnosis of chronic lymphocytic leukemia. To the best of our knowledge, this is the first reported case of chronic lymphocytic leukemia involving the subungual area. The authors' observation emphasizes the importance of taking a biopsy specimen in the differential diagnosis of subungual tumors.