A Rare Presentation of Dermatofibrosarcoma Protuberans of the Scalp Treated With "Slow-Mohs" Micrographic Surgery

Dermatofibrosarcoma protuberans (DFSP) is a rare, fibrohistiocytic tumor with intermediate malignancy.(1) While these tumors are slow-growing and only metastasize in 6% of cases,(2) they are often locally destructive, with relatively high local recurrence rates after initial excision. Overall annual incidence rates in the US are 0.84.(1) per million person-years,(2) though incidence among African Americans is nearly double that of Caucasians.(3) DFSP is most commonly seen on the trunk (42-50%), followed by the extremities (30-42%) and, rarely, on the head and neck (10-15%).(2,4) Other studies report that DFSP of the scalp accounts for under 5% of total cases.(5) However, the head and neck region is reported to have the highest tendency to recur locally, roughly 50-75% of cases.(4) Further, DFSP tumors on the scalp have the potential to metastases to the brain,(4) thus highlighting the importance for these tumors to be correctly diagnosed and treated early on. Partly due to its rarity and also its tendency to mimic other mainly benign lesions clinically, DFSP is often misdiagnosed, leading to years of delay in proper treatment and otherwise likely avoidable sequelae.(6) We describe a rare presentation of DFSP on the scalp of a 45-year-old African American woman successfully treated with "slow-Mohs" micrographic surgery. We also discuss the most common misdiagnoses for DFSP and scenarios when this tumor should be included in the differential and subsequent work-up.