The method of en face Frozen section in clearing periocular basal cell carcinoma and squamous cell carcinoma

Background: The senior consultants Ross Benger and Andrew Gal have been using en face frozen section histological margin control in removing cancer from the periocular region since 1985. The aim of this study was to determine the percentage of cases in which more than one resection was necessary in order to achieve clear margins. Methods: This is a retrospective study of patients treated at Drummoyne Eye Surgical Centre in the period 1999-2007, in whom removal of the eyelid cancer was decided to be with en face frozen section histological control. A record was kept of how many resections were necessary to achieve clear margins. Paraffin sections were subsequently examined for a final histopathological diagnosis. Results: Two hundred and fifty people were included in the study, of whom 204 had basal cell carcinoma (BCC) and 32 had squamous cell carcinoma (SCC). One hundred and twenty BCCs had a full-thickness eyelid "wedge" resection, of which 45% needed more than the standard two frozen sections taken to achieve clear margins. Eighty-four BCCs were removed using ring resection, of which 35.7% needed more than the standard initial resections (peripheral annulus and deep disc) to achieve clear margins. Conclusions: Our study showed that a significant percentage of BCC and SCC lesions needed further resection after the initial frozen section edge checks to achieve clear margins. Intraoperative presence of the histopathologist increased the likelihood of achieving clearance of the cancer at a single operating session.