The Australian Mohs database: periocular squamous cell carcinoma.

OBJECTIVE: To present the results of all patients with periocular squamous cell carcinoma (SCC) treated with Mohs' micrographic surgery (MMS) in Australia between 1993 and 1999.

DESIGN: Prospective, noncomparative, multicenter, interventional case series.

PARTICIPANTS: Seventy-nine patients undergoing MMS for periocular SCC over a 7-year period (1993-1999).

MAIN OUTCOME MEASURES: Recurrence after MMS, site, size, prior recurrence, defect size, histologic subtype, and presence of perineural invasion (PNI).

RESULTS: Seventy-nine patients had 54 (68%) lower eyelid, 19 (24%) medial canthus, and 6 (7.6%) upper eyelid SCCs. The most common histologic subtypes were well differentiated (48.7%) and moderately differentiated (35.1%) SCC. Seventy-three percent were primary tumors and 27% were recurrent tumors. Three (4.3%) cases had histologically confirmed PNI. Two of the 3 cases with PNI were recurrent (P = 0.1355), and surgical excision was the most frequent prior treatment (P = 0.0192), with up to 3 prior excisions in 1 case. None of the patients with PNI received adjunctive radiotherapy, and none have recurred with follow-ups to date of 4, 5, and 6 years, respectively. A median follow-up of 73 months (mean, 77.3; range, 42-117) was available in 56 (71%) cases, of which 2 (3.64%; exact 95% confidence interval, 0.44%-12.53%) recurred. Both cases were primary, moderately differentiated SCCs.

CONCLUSION: This is the largest reported prospective series of periocular SCC managed by MMS, with a median follow-up of over 5 years. It demonstrates that MMS has the lowest reported recurrence rate (3.64%) of any treatment modality for periocular SCC. That there were no recurrences for cases with PNI further emphasizes the importance of margin-controlled excision for periocular SCC.