Mohs micrographic surgery of the nail unit.

Malignancies of the nail unit are relatively uncommon, with squamous cell carcinoma (SCC) representing most of the reported cases. Squamous cell carcinoma of the nail unit, although commonly considered to be a curable malignancy, can and does kill. Review of the literature as well as a personal series confirm that Mohs micrographic surgery is an ideal treatment for periungual and subungual SCCs without osseous involvement. In addition, the anatomy and histology of nail unit SCC, as well as prognostic factors and perioperative evaluation as they relate to performing Mohs micrographic surgery, are reviewed.