A multicentre review of the histology of 1012 periocular basal cell carcinomas

Aims: To evaluate primary periocular basal cell carcinomas (BCCs) in depth including comparing histological margins with subtype, location and surgical specialty after wide local excision. Methods: A retrospective review was performed for all BCCs excised from three hospitals over 5 years, covering a population of just over 1 million. Tumours were classified according to histological subtype location. Incomplete excision rates and margins were analysed in detail and comparisons made. Results: The most common subtype found was nodular followed by infiltrative. Lesions were most commonly located at the lower lid. Infiltrative BCCs were associated with perineural invasion and incomplete excision despite the largest peripheral margins. Superficial BCCs had the smallest mean peripheral margin but the largest mean deep margin. 2 mm histological margins gave an 83.7% complete excision rate, 6.4% incomplete excision rate and 7.1% where the clearance margin was 0.3 mm or less. Conclusion: Distribution of eyelid BCCs based on subtype and periocular location mirrored the general consensus. Infiltrative BCCs should be excised with wider margins or referred for Mohs surgery, especially if the medial canthus is involved. Superficial BCCs should be excised with wider but shallower surgical margins. Ophthalmologists were more likely than dermatologists or plastic surgeons to incompletely excise a periocular BCC, which is reflective of their more difficult case mix.