Introduction: Mohs micrographic surgery is a treatment option that increases the cure rate in various types of skin cancer, offering greater tissue preservation and lower recurrence rates. Objective: To describe clinically and histologically the tumors operated on with Mohs micrographic surgery, and to draw correlations to the number of stages and the type of surgical reconstruction performed. The operations were performed at a private clinic in the municipality of Rio de Janeiro, Brazil that is a specialist center for this technique. Methods: Retrospective, observational, cross-sectional/transversal study was carried out based on the review of medical records. Results: A study was conducted of 93 tumors in 84 patients, operated on between April 2010 and August 2012, and followed up with until August 2013 (12 to 42 months). Findings: 47.61% of patients were men and 52.38% were women, the mean age was 62.89 years; predominant phototypes: II (44%) and III (43%); 6 cases (6.45%) of squamous cell carcinoma, 87 (93.54%) of basal cell carcinoma; 74.19% were primary tumors; the nose was the most frequent site (46.24%); a single surgical stage was performed in most cases, with flaps (44%) being the more frequently performed type of closure. There was recurrence in one patient, who required reoperation in October 2012 and followed without new recurrence. Conclusions: Mohs surgery has proven effective with high cure rates and a minimal recurrence rate, especially in lesions located in the face's H area of risk.

Keywords: MOHS SURGRY, CARCINOMA, BASAL CELL, CARCINOMA, SQUAMOUS CELL.

Basal cell carcinoma is a locally invasive malignant tumor, most frequently affecting Caucasian people. The nasal ala is a frequent site for this neoplasia. The treatment of choice is surgical, and Mohs micrographic surgery is one of the indicated techniques for presenting great accuracy in the histological control of margins and high cure rates with low recurrence rates. In this location, not only is a cure needed, but also the maintenance of facial aesthetics. The authors describe five cases of complete amputation of the nasal ala after Mohs micrographic surgery, with reconstruction using the Spear's flap.

Keywords: CARCINOMA, BASAL CELL; MOHS SURGERY; SURGICAL FLAPS.