Incidence of residual basal cell carcinoma in patients who appear tumor free after biopsy

Background: Basal cell carcinoma (BCC) biopsy sites often heal with no clinical evidence of residual tumor. Objective: The purpose of our study is to determine whether such patients require further therapy If biopsies can be curative, health care costs can be reduced by avoiding unnecessary surgery. Methods: We prospectively evaluated 41 consecutive subjects with 42 biopsy-confirmed BCCs who appeared disease free. Each biopsy site was excised and processed by the Mohs micrographic technique. The tissue block was sectioned horizontally at 30-mu m intervals until exhausted. Sections were stained and examined microscopically for residual tumor. Results: Tumor was identified in 28 (66%) of 42 cases. No statistically significant relationship was found between the presence or absence of residual tumor and the following variables: age, sex, tumor location, biopsy technique, histopathologic subtype, scar size, time from biopsy to surgery and extent of inflammation in histologic sections. Conclusion: Our data suggest that patients with small (< 1 cm) primary BCCs that appear to be completely removed after a biopsy procedure are at risk for recurrence without further treatment.