Randomized Comparison of Mohs Micrographic Surgery and Surgical Excision for Small Nodular Basal Cell Carcinoma: Tissue-Sparing Outcome

BACKGROUND Mohs micrographic surgery (MMS) is recognized globally as the criterion standard for high-risk basal cell carcinoma (BCC). The main advantage of MMS over conventional surgery is the chance of complete tumor removal, but it is also thought, based on experience, to be tissue sparing. OBJECTIVE To determine whether MMS leaves smaller surgical defects than standard surgery. METHODS AND MATERIALS This was a randomized trial involving 30 patients with a clinical diagnosis of BCC. Patients were randomly assigned to MMS or standard surgery. In the standard surgery group the BCCs were excised with 4-mm margins. In the MMS group, tumors were excised with 2-mm margins and subsequent stages of MMS until the tumor was completely removed. An observer unaware of the treatment allocation calculated the defect size. The main outcome measure was defect size in mm(2). RESULTS The median area of the surgical defects in the MMS group was 116.6 mm(2), versus 187.7 mm(2) in the standard surgery group (95% confidence interval for difference=61-126, p <.001). CONCLUSIONS This is the first randomized trial demonstrating that MMS is a tissue-sparing treatment. Trial registration: http://www.clinicaltrials.gov Identifier: NCT00571363. The authors have indicated no significant interest with commercial supporters.