The Australian Mohs database, part I - Periocular basal cell carcinoma experience over 7 years

Abstract

<h4>Objective</h4>To present the findings of all patients with periocular basal cell carcinoma (BCC) treated with Mohs' micrographic surgery (MMS) in Australia between 1993 and 1999.<h4>Design</h4>Prospective, noncomparative, multicenter, interventional case series.<h4>Methods</h4>Prospective series of 1295 patients undergoing MMS for periocular BCC over a 7-year period (1993-1999).<h4>Inclusion criteria</h4>Periocular BCC referred for MMS.<h4>Main outcome measures</h4>Site, tumor size, prior occurrence, defect size, histologic subtype, and presence of perineural invasion.<h4>Results</h4>Twelve hundred ninety-five patients had 615 (47.5%) lower eyelid, 626 (48.3%) medial canthus, and 51 (3.9%) upper eyelid BCCs. The most common histologic subtypes were nodulocystic (39.5%) and infiltrating (34.8%) (P = 0.0008). Sixty-eight percent were primary and 32% were recurrent tumors. Previously recurrent BCCs were larger (P<0.0001), with larger defects (P<0.0001) than primary BCCs, and had more subclinical extension (P<0.0001) requiring more levels for complete excision (P<0.0001). Furthermore, superficial BCCs were more likely to have a prior occurrence (P<0.0001). In this series, perineural invasion was found in 1% of cases, with greater subclinical tumor extension in such cases (P = 0.0657).<h4>Conclusion</h4>The Australian MMS database is the largest prospective, nationwide series of high-risk periocular BCC managed by MMS. Almost 50% of tumors were at the medial canthus, with nodulocystic and infiltrating being the most common histologic subtypes. Recurrent BCCs comprised a third of tumors and were larger, with larger defects and more subclinical extension than primary BCCs. Perineural invasion was found in 1% of cases and also had greater subclinical extension.