Assessment of Clinical Features of Superficial Basal Cell Carcinomas Treated With Mohs Micrographic Surgery.

BACKGROUNDSuperficial basal cell carcinomas (sBCCs) are often regarded as indolent, yet their behavior across anatomic sites and Mohs appropriate use criteria (AUC) zones, particularly at nonfacial locations, remains undercharacterized.

OBJECTIVETo characterize discordance, upstaging, and Mohs micrographic surgery outcomes of sBCCs by anatomic location, subsites, and AUC zone.

METHODSSingle-center retrospective review of 622 biopsy-confirmed sBCCs treated by Mohs micrographic surgery. Patient demographics, anatomical location, lesion size, Mohs stages, and intraoperative discordance (any nonsuperficial subtype) or upstaging (aggressive subtypes) was analyzed.

RESULTSThe mean stages to clearance was 1.82, with a mean defect increase of 2.35 cm2. Head/neck tumors were smaller yet required more stages: 27.9% cleared in 1 stage versus 55.2% (trunk) and 52.2% (extremity) (p < .001). Nearly half of trunk (44.8%) and extremity (47.8%) tumors required 2 or more stages. Discordance was observed in 19.5% of lesions (28.2% head/neck, 13.8% extremity, and 8.4% trunk) and upstaging was observed in 8.4% of lesions, both declining across AUC zones (Area H > M > L; p < .001). The nose had the highest discordance rate (51.8%); upstaged lesions more often required complicated repair (odds ratio 4.21).

CONCLUSIONsBCC discordance and upstaging follow an AUC zonal gradient. These data may inform future AUC refinement and patient counseling.

Abstract from PubMed