Incidence of Residual Nonmelanoma Skin Cancer in Excisions After Shave Biopsy

Abstract

Nonmelanoma skin cancer is an increasingly common disease that is typically treated surgically. After histopathologic confirmation by biopsy, the carcinoma is typically removed by excision, but not all excisional specimens contain residual carcinoma. To define the rate of residual basal and squamous cell carcinomas within excisional specimens after shave biopsy in a general dermatology office. We retrospectively reviewed 439 consecutive cases sent to a single dermatopathology lab from a practitioner's general dermatology office who also performs Mohs micrographic surgery. One hundred cases had a histopathologically proven carcinoma on biopsy with subsequent excision. Histopathologic type, location, age, sex, and time from biopsy to excision were all analyzed for statistical association. Of 57 cases of basal cell carcinoma, 34 (59.6%) had positive residuals. Of 43 cases of squamous cell carcinoma, 12 (27.9%) had positive residuals. Histologic type was significantly associated (p=.002) with residual carcinoma in excisional specimens, with basal cells 2.13 times as likely to have residual carcinoma present. The rate of residual nonmelanoma carcinoma in excision specimens after shave biopsy was found to be different from previously reported in the literature. These data may have therapeutic ramifications if further substantiated.