Plantar verrucous carcinoma: report of a case treated with Boyd amputation followed by reconstruction with a free forearm flap.

Verrucous carcinoma is a relatively rare, well-differentiated, squamous cell carcinoma. Although it is slow-growing and mimics benign skin lesions, it can cause extensive local destruction that necessitates amputation. It is often underdiagnosed as a benign tumor in its early course. We report a case of extensive verrucous carcinoma on a recalcitrant ulcer and a severe long-standing scar around it on the sole of the right forefoot, which had been treated as a benign tumor for more than two years. We treated it successfully with amputation of the foot and were able to spare the heel by using a free innervated forearm flap to cover the defect at the stump. The present case should remind clinicians that a verrucous lesion developing on a refractory ulcer may be a complex malignant neoplasm; an accurate diagnosis is difficult without a combination of clinical features and pathological findings from an adequately deep specimen.