Scalp Dermatofibrosarcoma Protuberans: A Rare Localization Mimicking an Arteriovenous Malformation – A Case Report

Abstract: Background: Dermatofibrosarcoma protuberans (DFSP) is a rare, low-grade dermal sarcoma with a high risk of local recurrence. Scalp localization is extremely uncommon and may lead to diagnostic confusion. We report an unusual case of scalp DFSP in a young adult, initially misdiagnosed as an arteriovenous malformation (AVM), underlining diagnostic pitfalls and the importance of appropriate surgical management. Case Presentation: A 20-year-old man presented with a painless, progressively enlarging occipital scalp mass evolving over 18 months. Initial clinical and radiological findings were consistent with a vascular lesion. The patient underwent six sessions of sclerotherapy for presumed AVM without improvement. Surgical excision revealed a fusocellular mesenchymal proliferation on histopathology, consistent with DFSP. Immunohistochemical staining showed diffuse CD34 positivity and was negative for PS100, AML, Desmin, and STAT6. Due to close surgical margins (<0.1 cm), a re-excision was performed with wide local margins and reconstruction by full-thickness skin graft. No residual tumor was detected on histological review. Follow-up at 3 and 10 months showed satisfactory healing and no signs of recurrence. Conclusion: This case highlights a rare presentation of DFSP mimicking a benign vascular anomaly. Accurate diagnosis through histopathology and immunohistochemistry is essential. Wide local excision remains the gold standard for treatment to minimize recurrence risk.