Recurrence of periocular basal cell carcinoma and squamous cell carcinoma after Mohs micrographic surgery: a retrospective cohort study

Background Despite the widespread use of Mohs micrographic surgery (MMS) for periocular basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) - together called keratinocyte carcinoma (KC) - follow-up data regarding recurrences are limited. Objectives To investigate the recurrence rate for periocular KCs after MMS and to describe our experience with interdisciplinary collaborations. Methods Patients with periocular KCs treated with MMS between 2006 and 2016 in a tertiary MMS referral hospital were included in this retrospective cohort study. Descriptive statistics were used to describe the MMS procedure-related characteristics. Using follow-up data from the electronic patient records and linkage with the Dutch nationwide network and registry of histopathology and cytopathology on 30 June 2017, the recurrence rate was evaluated and calculated using a cumulative incidence curve. Results In total, 683 (93 center dot 7%) periocular BCCs and 46 (6 center dot 3%) SCCs were treated with MMS. Three-quarters (n = 549) were primary tumours and the majority were located at the medial canthus or lower eyelid (n = 649, 89 center dot 0%). In 505 MMS procedures (69 center dot 3%) an oculoplastic surgeon participated, and in 63 patients (8 center dot 6%) a plastic surgeon performed the reconstruction. After a median follow-up of 46 months the recurrence rate was 3 center dot 0%, based on 22 recurrences (20 BCCs and two SCCs). Conclusions MMS is an excellent treatment option for periocular KCs, with a low recurrence rate. Due to this specific anatomical location an interdisciplinary approach should pre-eminently be considered.