Objective: To present the findings and report the outcomes of all patients with periocular squamous intraepidermal carcinoma (IEC) treated with Mohs micrographic surgery (MMS) in Australia between 1993 and 1999.
Design: Prospective, noncomparative, multicenter, interventional case series.
Methods: A prospective series of 53 patients undergoing MMS for periocular IEC over a 7-year period (1993-1999).
Main outcome measures: Recurrence, site, size of IEC, prior recurrence, and size of final defect.
Results: Fifty-three patients had 27 (51%) lower eyelid, 17 (32%) medial canthus, and 9 (17%) upper eyelid IEC. Most (85%) of the IECs were present for less than 5 years. Fifty-eight percent were primary IECs, and 42% were recurrent IECs. There were no differences in the clinical features of primary and recurrent IECs. Significant subclinical tumor extension was found, whereby the defect exceeded tumor size by at least 2 size groups (> or =2 cm) in 25% of cases. Follow-up to date was available in 68% (36 of 53) of cases (19 primary and 17 recurrent IECs). With a mean follow-up of 77.4 months (median, 75; range, 44-120 months), 3 (8.3%; exact 95% confidence interval 1.8%-23.1%) cases recurred. Hence, the recurrence rate was 5.3% (1 of 19) for primary periocular IEC and 11.8% (2 of 17) for recurrent periocular IEC.
Conclusions: The Australian MMS database provides data for the first prospective series of periocular IEC managed by MMS. Periocular IEC demonstrates significant subclinical tumor extension, with no significant differences in the clinical features of primary and recurrent lesions. Compared with other published studies, the recurrence rate of 5% and 12% for primary and recurrent lesions, respectively, with more than 5-years of follow-up for most cases emphasizes the importance of margin-controlled excision for periocular IEC.