What Is DFSP?
Dermatofibrosarcoma protuberans (DFSP) is a rare, low-to-intermediate grade sarcoma arising in the dermis. It grows slowly, often over years, and is locally aggressive — meaning it tends to infiltrate along tissue planes well beyond what is visible on the skin surface — but it very rarely spreads to distant sites. Because of this pattern, complete surgical removal with clear margins is the central goal of treatment, and inadequate initial excision is the main cause of local recurrence.
Causes & Risk Factors
The exact cause of DFSP is not fully understood. Most cases are associated with a specific chromosomal translocation (involving the COL1A1 and PDGFB genes), which is not inherited but arises within the tumour itself. It most commonly affects adults in early-to-mid adulthood and occurs most often on the trunk, followed by the limbs.
Signs to Look For
- A firm, indurated plaque or nodule, often skin-coloured, pink, red or brown
- Slow growth over months to years — DFSP can easily be mistaken for a scar, dermatofibroma, or other benign lesion for a long time before diagnosis
- The lesion may become raised or nodular ("protuberant") as it grows, giving the condition its name
Diagnosis
Diagnosis is confirmed by biopsy, with immunohistochemistry (DFSP characteristically stains positive for CD34) helping distinguish it from other spindle cell tumours, including benign dermatofibroma. Because DFSP frequently extends further beneath the skin than it appears, MRI imaging is often used before surgery to help map the extent of the tumour and plan the operation.
Treatment
- Wide local excision — the traditional approach, removing the tumour with a generous margin (often 2–3cm) of surrounding tissue in all directions, including deep to the underlying fascia
- Mohs micrographic surgery — increasingly preferred where available, examining the complete excision margin under the microscope during the procedure to confirm clearance while sparing as much healthy tissue as possible — particularly valuable given DFSP's tendency to extend along tissue planes unpredictably
- Targeted molecular therapy (imatinib) — reserved for unresectable or metastatic disease, exploiting the specific genetic translocation that drives most DFSP
- Reconstruction — planned according to the size and site of the defect once clearance is confirmed
Given its classification as a soft tissue sarcoma, DFSP is managed with input from a specialist sarcoma multidisciplinary team (MDT), even though most cases are treated surgically without the need for chemotherapy or radiotherapy.
Prognosis
With complete surgical clearance, the prognosis for DFSP is very good — metastasis is rare. The main risk is local recurrence if the initial excision was incomplete, which is why achieving confirmed clear margins at the first operation, ideally with Mohs surgery or equivalent margin control, is so important.
Related Pages
- Skin Cancer Excision & Reconstruction
- Soft Tissue Sarcoma of the Skin
- Reconstructive Techniques: Skin Grafts & Flaps