Verrucous Carcinoma of the Foot: A Single Canadian Center Experience on Diagnosis, Management, and Outcomes.

Introduction: Verrucous carcinoma (VC) was first described in 1948 by Dr. Ackerman. It is a low-grade cutaneous squamous carcinoma that usually develops in the oral cavity, the anogenital region, and the plantar surface of the foot. Clinically, there is low suspicion for malignancy given the slow growth of VC lesions and their wart-like appearance. Diagnosis can be difficult because of the benign histological appearance with well-differentiated cells and absence of dysplasia. Surgical excision is the only satisfactory form of treatment for plantar VC; however, this becomes difficult given its benign clinical appearance and the pathologic misinterpretation of the lesion as a benign hyperplasia. While there are case reports and retrospective studies of patients with plantar VC in the literature, we present the largest case series of plantar VC within North America, with recurrence despite negative margins.

Methods: We report on all the plantar VC excised between 2014-2023. We report six cases of VC, their treatment, and their outcomes.

Results: Six patients obtained a diagnosis of plantar VC by incisional biopsy. All patients underwent excision of their lesions and had negative margins reported on the final pathology. All patients developed nonhealing wounds at the site of their lesion excision; therefore, biopsies were performed to confirm a recurrence. All patients had a recurrence of VC at the initial site. All patients underwent re-excision of the lesions. Despite negative margins again on final pathology, all patients had a subsequent second recurrence. Ultimately, all patients underwent an amputation as definitive management. Each patient had an average of 3 operations. There were 4 different surgeons and different pathologists reporting their findings.

Conclusions: Our experience with plantar VC suggests that an aggressive approach to surgical management is needed. Furthermore, management is optimized with the combined expertise of an experienced dermatopathologist and surgeon. Despite negative margins and repeated excisions, VC lesions recur and invade local tissues to the extent that only amputation of the involved foot has resulted in cure.