Clinical Hours: Mon-Fri, 8AM - 3PM(905) 493-5700
1885 Glenanna Road, Suite 220, Pickering, ON, L1V 6R6
Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive skin tumour with high recurrence risk, treated primarily with wide surgical excision.
Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive soft tissue sarcoma that arises in the dermis and infiltrates into the subcutaneous tissue. It is the most common cutaneous sarcoma, though it remains an uncommon tumour overall. DFSP is characterized by slow, progressive growth and a high rate of local recurrence following inadequate excision, but it has a low potential for distant metastasis.
The tumour most commonly presents in young to middle-aged adults, with a peak incidence between the ages of 20 and 50. It occurs with approximately equal frequency in men and women. DFSP most frequently develops on the trunk, followed by the proximal extremities, and less commonly on the head and neck. The estimated incidence is approximately 4 to 5 cases per million persons per year.
The hallmark molecular abnormality in DFSP is a chromosomal translocation, most commonly t(17;22)(q22;q13), which results in the fusion of the COL1A1 gene on chromosome 17 with the PDGFB gene on chromosome 22. This gene fusion produces a chimeric protein that leads to constitutive activation of platelet-derived growth factor receptor beta (PDGFR-beta), driving uncontrolled cell proliferation.
In the majority of cases, no clear external cause is identified. Rare associations have been reported with prior trauma, surgical scars, burn scars, and sites of previous radiation therapy, though these remain uncommon. DFSP is not considered a hereditary tumour and does not follow a familial inheritance pattern.
DFSP typically presents as a slow-growing, firm, indurated plaque or nodule within the skin. The clinical features vary depending on the stage of growth:
DFSP grows by extending irregular, tentacle-like projections into the surrounding subcutaneous fat, which accounts for the high local recurrence rate when excision margins are insufficient. The tumour may be present for years before diagnosis, as its slow growth and initially innocuous appearance can lead to delayed recognition.
A skin biopsy is essential for establishing the diagnosis of DFSP. A deep punch biopsy or incisional biopsy that includes subcutaneous tissue is preferred, as the tumour extends into the deeper layers of the skin.
Histopathologic examination reveals a characteristic storiform (cartwheel) pattern of uniform spindle cells infiltrating the dermis and extending into the subcutaneous fat in a honeycomb pattern. Immunohistochemistry is strongly positive for CD34, which distinguishes DFSP from other spindle cell tumours such as dermatofibroma. Molecular testing can confirm the COL1A1-PDGFB gene fusion.
Imaging studies, such as MRI, may be obtained for larger or deeper tumours to assess the extent of subcutaneous involvement and to aid surgical planning. The fibrosarcomatous variant of DFSP (DFSP-FS) is a higher-grade transformation that carries an increased risk of metastasis and requires particular attention in pathologic evaluation.
Surgical excision is the primary treatment for DFSP. Due to the tumour's irregular subclinical extensions, adequate surgical margins are critical to minimizing the risk of local recurrence.
Wide local excision with margins of 2 to 3 centimetres is recommended for standard DFSP treatment. This approach accounts for the subclinical tumour extensions that may not be visible on clinical examination. Mohs micrographic surgery, which involves the examination of 100 percent of the surgical margin, offers the highest cure rate and may allow for tissue conservation, particularly in anatomically sensitive locations.
For complex or large tumours, skin cancer surgery with reconstruction may be required to achieve clear margins while preserving function and cosmesis.
Long-term post-treatment surveillance is essential following treatment of DFSP, as local recurrence can occur years after initial excision. Regular clinical examinations of the surgical site and surrounding skin are recommended. For patients with high-risk features, such as the fibrosarcomatous variant, multidisciplinary cancer care coordination may be appropriate to ensure comprehensive management.
In cases where surgical excision is not feasible or for locally advanced or metastatic disease, imatinib mesylate, a tyrosine kinase inhibitor targeting PDGFR-beta, may be considered. This targeted therapy exploits the molecular driver of DFSP and has demonstrated clinical responses in patients with the COL1A1-PDGFB fusion. Imatinib is typically reserved for cases that are not amenable to complete surgical removal.
Any slowly growing, firm nodule or plaque within the skin that persists or enlarges over time should be evaluated by a dermatologist. Because DFSP can initially resemble benign conditions such as scars, keloids, or dermatofibromas, a persistent or changing skin lesion that does not have a clear diagnosis warrants further assessment, including biopsy.
A referral from a family physician is typically required to access dermatology services at the Centre for Medical and Surgical Dermatology. Early diagnosis and complete surgical removal by an experienced dermatologist provide the best outcomes and minimize the risk of local recurrence.
Your feedback helps us improve our condition information
A physician referral is required to access our medical services. Contact your primary care provider to begin the referral process.