Dermatofibrosarcoma protuberans: slow Mohs procedures in the diagnostic laboratory

Dermatofibrosarcoma protuberans (DFSP) is a rare superficial sarcoma which is believed to be of fibroblastic or myofibroblastic derivation. It is believed to have been first described as a progressive and recurring dermatofibroma by Darier and Ferrand in 1924, and Hoffman is generally recognised for officially coining the term dermatofibrosarcoma protuberans in 1925.1 The tumour is of an intermediate- to low-grade type. Although metastasis is rare, it invades locally and has a high recurrence rate. The tumour is commonly found within the dermis but it can invade deep into the subcutis, infiltrating the fatty tissue mainly via the fibrous septa between the adipocytes.

Conventionally, surgical removal represents the treatment of choice, ensuring margins of 3 cm or more of clinically uninvolved skin and underlying fascia. These tumours can expand to relatively large size and, if arising on the head and neck, can result in disfiguring and problematic reconstruction following removal.

Mohs micrographic surgery is widely employed for the removal of more conventional tumours (eg basal cell carcinoma) because of established improved cure rates over conventional surgical removal, maximal conservation of normal uninvolved tissue, and often an improved overall cosmetic result. However, the single significant positive indicator for the use of a Mohs procedure is that it enables the examination of the entire surgical margin, a facility not afforded by any other surgical procedure currently available. More recently, its popularity as a treatment for DFSP has been championed.