Frozen Section Mohs Micrographic Surgery for Dermatofibrosarcoma Protuberans-A Case Series of 38 Patients in NSW,...

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumour with a locally infiltrative growth pattern that has high rates of recurrence. Mohs micrographic surgery is recommended as the gold-standard treatment over wide local excision (WLE) due to tissue-sparing and reduced recurrence rates. No previous data on surgical outcomes following Mohs Micrographic Surgery (MMS) for DFSP have been reported in Australia to date. This study aims to review the outcomes of DFSP treated with frozen-section MMS across three centres in New South Wales (NSW), Australia, and compare these outcomes with those in the current literature.

A retrospective review of patients who underwent MMS for DFSP between 2010 and 2023 was performed. Patient demographics, histological findings, surgical treatment and follow-up data were collected. Recurrence was assessed through electronic medical records, clinical assessments by a dermatologist or general practitioner, and patient self-report.

In all, 38 cases of DFSP were included (27 female, 11 male; median age 39 years, range 16-64). The trunk was the most common site. Clinical margins and Mohs stages were recorded in 37 of 38 cases, with 73% of cases cleared with clinical margins of ≤ 20 mm. Clinical or self-reported follow-up was available for 28 of 38 patients (73.6%) over a mean of 51 months (range, 5-132 months). No local recurrences were identified during this period.

This is the first Australian case series on MMS for DFSP. Our findings demonstrate no recurrences with follow-up and demonstrate that MMS may achieve clearance with smaller clinical margins than WLE. These results support international guidelines recommending MMS as the gold-standard treatment and highlight the need to improve access to MMS in Australia.