Efficacy of fluorescence diagnosis-guided Mohs micrographic surgery for pigmented vs non-pigmented basal cell carcinoma.

Pigmented basal cell carcinoma (PBCC) occurs more frequently in Asian population. The efficacy of fluorescence diagnosis (FD) for PBCCs treated with Mohs micrographic surgery has not yet been determined. This study enrolled 255 patients with 258 biopsy-proven BCC lesions: 199 PBCCs (77.1%) and 59 non-PBCCs (22.9%). We compared the clinicopathological and surgical features of the PBCCs and non-PBCCs. Each group was divided into 2 sub-groups, those assessed and not assessed by FD, to retrospectively analyse surgical features. Aggressive histological subtypes were less prevalent in PBCCs than in non-PBCCs. PBCCs required significantly fewer stages of Mohs excision, with significantly smaller surgical margins and surgical depth, than non-PBCCs. FD did not confer any benefits on PBCCs during Mohs micrographic surgery. However, non-PBCCs assessed by FD required significantly fewer Mohs stages, with significantly smaller surgical margins, than lesions not assessed by FD. These findings suggest that FD should be performed before Mohs micrographic surgery to delineate the margins of non-PBCCs in Asians.