Mohs Micrographic Surgery for Primary Versus Recurrent or Incompletely Excised Facial High-risk Basal Cell Carcinomas.

Facial high-risk basal cell carcinomas are preferably treated with Mohs micrographic surgery, but only 10% of patients are offered Mohs micrographic surgery in Sweden. The aim of this retrospective study was to examine the differences between primary and recurrent or incompletely excised facial high-risk basal cell carcinomas undergoing Mohs micrographic surgery, with regard to the number of stages, final defect sizes, reconstructive techniques and other consequences. The study was performed during the period 2012 to 2019 at our centre. A total of 903 basal cell carcinomas in 813 patients (70.1% primary, 10.4% incompletely excised and 19.5% recurrences) were included. The mean number of Mohs micrographic surgery stages was significantly lower for primary basal cell carcinomas compared with recurrences (p = 0.03), and the mean final defect size was significantly smaller in primary basal cell carcinomas compared with both recurrent (p < 0.0001) and incompletely excised (p = 0.003) tumours. Primary basal cell carcinomas tended to more often be reconstructed by primary closure (p = 0.08). Mohs micrographic surgery indications for facial high-risk basal cell carcinomas should be respected and used more frequently on primary basal cell carcinomas, in order to enable better utilization of resources and improved outcomes for the patient.