Carcinoma cuniculatum: an atypical presentation in the foot.

Carcinoma cuniculatum is a rarely occurring, low-grade variant of squamous cell carcinoma most commonly found in the forefoot. It should be suspected in the differential diagnosis for chronic nonhealing verrucous wounds. The initial diagnosis of carcinoma cuniculatum is difficult and often delayed and can require repeated histopathologic evaluation by an experienced pathologist. In many cases, the final diagnosis will be made from the microscopic findings correlated with the clinical examination findings. Metastasis from carcinoma cuniculatum is rare, although it can invade deep into the soft tissues and can extend to the bone. Wide local excision with a 5-mm tumor-free margin has been the recommended treatment. If the tumor extends into the bone, amputation might be warranted. The present report describes the case of an atypical carcinoma cuniculatum found in the hindfoot of an adult female and represents the surgical follow-up to the histopathologic description of the same patient's lesion as previously described in a published report.