Clinicopathological factors influencing the number of stages of Mohs surgery for basal cell carcinoma()

BACKGROUND: Mohs Micrographic Surgery (MMS) is commonly used to treat high-risk basal cell carcinoma (BCC). OBJECTIVES: Correlate clinicopathologic preoperative features with the number of MMS stages (primary endpoint) and margins (secondary endpoint) required for BCC complete excision. METHODS: We retrospectively analyzed BCCs treated by MMS in a 2-year period at the study’s institution. Variables studied included the patient gender, age, immune status, lesion size, location, if it was a primary, recurrent, or persistent tumor, histopathologic characteristics, number of surgical stages, and amount of tissue excised. RESULTS: 116 BCCs were included. The majority (61.2%, n = 71) required a single-stage surgery for complete clearance, requiring a final margins of 3.11 ± 2.35 mm. Statistically significant differences between locations in different high-risk areas (periocular, perioral, nose, ear) and the number of MMS stages required for complete excision (p = 0.025) were found, with periocular tumours requiring the highest mean of stages (2.29 ± 0.95). An aggressive histopathology significantly influenced the number of MMS stages (p = 0.012). Any significant relation between clinicopathological features and variation in the final surgical margins was found, just certain tendencies (male patients, persistent tumor, periocular location, and high-risk histopathological tumors required larger margins). Neither patient age or tumor dimension correlated significantly with both number of MMS stages and final surgical margins. STUDY LIMITATIONS: Limitations of this study include its single-center nature with a small sample size, which limits the value of conclusions. CONCLUSION: Main factors related to a greater number of MMS stages were periocular location and high-risk histopathological subtype of the tumor.