Mohs micrographic surgery for dermatofibrosarcoma protuberans: comparison of frozen and paraffin techniques

Background Due to the propensity for local recurrence, Mohs micrographic surgery ( MMS ) has been suggested for the treatment of dermatofibrosarcoma protuberans ( DFSP ) and it has shown improved clinical outcomes. Recently, some authors suggested that MMS using paraffin‐embedded sections (paraffin MMS ) is superior in DFSP treatment compared with the conventional frozen MMS method. However, there have been no studies comparing frozen and paraffin MMS for the treatment of DFSP . Objectives To compare the outcomes between DFSP patients who underwent frozen MMS and paraffin MMS . Methods Seventy‐one DFSP patients treated with frozen MMS ( n = 30) or paraffin MMS ( n = 41) from 2003 to 2017 at a single institution were retrospectively reviewed. Recurrence rate and recurrence‐free survival between frozen and paraffin MMS were assessed. Results During the mean follow‐up duration of 25.4 months, four patients (frozen MMS , n = 1; and paraffin MMS , n = 3) showed recurrence after MMS . Although the local recurrence rate of the frozen MMS group (3.3%) was lower than that of the paraffin MMS group (7.3%), the difference was not statistically significant. In addition, recurrence‐free survival was not significantly different between the two groups ( P = 0.168). Conclusions Frozen MMS , which has the advantages of shorter surgery time and immediate closure, is as effective as paraffin MMS in the treatment of DFSP .