A Useful Alternative Approach for the Treatment of Well-Demarcated Basal Cell Carcinoma: Surgical Excision and Margin Control with Tzanck Smear Test

OBJECTIVE To analyze the accuracy of the Tzanck smear test (TST) for margin control in surgery for well-demarcated basal cell carcinoma (BCC). METHODS AND MATERIALS Twenty-one patients with well-demarcated BCC were included in this study. After local anesthesia, the tumors were excised. The pathologist examined the frozen sections. If the tumor cells were observed in the margin, a re-excision was done. This procedure was repeated until the margin was tumor free. After each excision, Tzanck smear samples were taken from the defect area. The samples obtained were stained with May-Grunwald-Giemsa and examined. The accuracy of TST was then analyzed by comparison of the TST results with those of frozen section examination. RESULTS The sensitivity and specificity of TST for margin assessment were 1.00 (95% confidence interval (CI)=1.00-1.00) and 0.99 (95% CI=0.98-1.00), respectively. Positive and negative predictive values and the diagnostic accuracy for TST were 0.94 (95% CI=0.84-1.05), 1.00 (95% CI=1.00-1.00), and 1.00 (95% CI=0.99-1.00), respectively. No recurrences were observed in the average 2-year follow-up period. CONCLUSION The high accuracy of TST for margin control is encouraging to develop a practical alternative approach for the treatment of well-demarcated BCC. The authors have indicated no significant interest with commercial supporters.