Aims The aim is to study staged periocular basal cell carcinoma (BCC) excision in a tertiary oculoplastic referral centre in Sheffield, UK. In particular, we examined patients with close or positive margins and no tumour seen on re-excision to identify demographics and tumour characteristics in this population.

Methods A retrospective review of medical records of 437 cases of staged periocular BCC excisions over a 10-year period (2007–2017) was carried out. Patients had surgical excision with 3 mm clinically clear margins. Staged excision was performed for all cases included in this study. Standard reconstruction techniques were employed. Histopathology was analysed for tumour type, subtype and stage.

Results Over the 10-year period, of the 437 periocular BCCs, 156 had close or involved margins. Residual tumour was found in 29 (18.6%), whereas in 122 eyelids of 120 patients (78.2%) no residual tumour was identified on histological examination. Micronodular (54.1%) and nodular (23.7%) growth patterns of BCC, as well as lower eyelid location (72.1%), were the most prevalent in this population. Two patients (1.6%) had recurrence of BCC over a mean follow-up of 57 months (range 1–125 months).

Conclusions A significant proportion of BCCs transected on initial excision show no residual tumour in the re-excision specimens. In the interval between initial excision and re-excision, there may be eradication of the residual tumour. The exact mechanisms for this are unclear, however, and re-excision remains the appropriate recommended course in the presence of involved surgical margins of periocular BCC, particularly when high-risk tumour subtypes are encountered.