To investigate the safety of planned two-stage excision and reconstruction of periocular basal cell carcinomas (BCC), including simultaneous further excision and reconstruction in selected cases with involved margins after the first excision. High-risk anatomy and the definition of a clear/close margin were analysed.

A retrospective case-notes review of consecutive patients undergoing surgery at Bristol Eye Hospital and Aintree University Hospital over a five-year period.

412 patient surgical episodes in total from the two centres were identified. A two-stage surgical excision and reconstruction was planned in 332 (81%), 63 (15%) had one-stage, 16 (4%) three stage and 1 six-stage. A 2mm excision margin was used in 363 (88%); 3mm in 22 (5.3%) with 37 (9%) not documented. 73 (18%) of patients had a re-excision due to a close or involved initial surgical margin. Only 11 (15%) had tumour identified in this re-excision. All 11 had an initial positive margin. 9 of these were completely excised at this 2nd stage. 2 (0.49%) had a close or involved margin requiring a third excision. Tumour involving the margin in an initial excision increases the relative risk of finding BCC in the re-excision ten-fold. Tumour location was also a critical finding of our study with medial canthal lesions increasing the risk of incomplete surgical control by 2.5 times.

A planned two-stage procedure is a safe and effective method for treating selected periocular BCC. An involved margin increases the risk of residual tumour ten fold; conversely a close margin (>0.1mm) is relatively safer. Tumour location is also important. Greater consensus is required between surgeons and histopathologists in defining safe tumour management.