Biopsy type does not affect the number of stages during Mohs micrographic surgery: a retrospective study

Abstract

Mohs micrographic surgery (MMS) is the treatment of choice for high-risk basal cell carcinoma (BCC). However, there are no evidence-based recommendations regarding which biopsy type is more appropriate to obtain tumour samples prior to MMS. Shave or punch biopsies are performed depending on the clinical characteristics of the tumour, surgeon experience and local protocols. However, biopsy type might result in difficult histopathological interpretation and influence the practical implementation of MMS. We performed a retrospective study on 208 consecutive BCCs treated with MMS. Of the 208 BCC biopsies, 42 (20.2%) were obtained by the shave method and 166 (79.8%) via punch. Those obtained with the shave technique had a mean of 1.64 stages vs. 1.69 stages with the punch technique (P = 0.130). These findings suggest biopsy type does not affect Mohs surgery performance. The biopsy type of choice is the one deemed adequate for each specific case to obtain a diagnosis and tumour subtyping., In this study including 208 primary basal cell carcinomas undergoing Mohs micrographic surgery (MMS), there were no differences in the mean number of stages, regardless of which biopsy type was performed (shave vs. punch). The biopsy technique might affect correct subtype identification; however, there were also no differences in the rate of upstaging. Any tissue reaction could also result in difficult histopathological interpretation on frozen sections; however, this was not evident in our study. It seems that biopsy type, shave vs. punch, does not affect MMS performance; thus the more appropriate biopsy type is the one deemed adequate for each specific case in order to obtain a diagnosis as well as tumour subtyping.