Verrucous carcinoma of the nail unit.

Verrucous carcinoma (VC) of the nail bed and matrix is a rare malignancy that is often misdiagnosed as a benign condition. We present a case of a 65-year-old woman with a 2-year history of a progressive right fourth fingernail verrucous plaque replacing and surrounding her entire fourth fingernail. Diagnosis of VC was confirmed by a longitudinal biopsy and patient underwent en bloc excision and skin graft placement. The patient remained disease free with acceptable function of the digit at 24 months of follow-up. Although uncommon, VC must be considered in all patients with a persistent and enlarging verrucous lesion involving the nail apparatus. Preoperative evaluation must include an adequate biopsy specimen to avoid misdiagnosis of verruca vulgaris. Digital radiographs are recommended to evaluate local invasion to bone.