Fibrosarcomatous dermatofibrosarcoma protuberans – an aggressive variant of sarcoma presenting as a breast tumour

Abstract Introduction Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma. Fibrosarcomatous Dermatofibrosarcoma Protuberans (FS‐DFSP) of the breasts is an even rarer entity. Complete surgical excision with a clear margin is the standard treatment for localized disease. This case report aims to enhance clinicians' understanding of this rare malignancy. Presentation of Case A 37‐year‐old female presented with a palpable lump in the right breast. On ultrasonography, a lesion appeared as a lobulated and hypoechoic mass with increased vascularity. Core biopsy showed a spindle cell tumour with atypical features. The patient underwent a wide local excision of tumour. Final pathology revealed FS‐DFSP. Discussion FS‐DFSP has its distinguishable imaging and histopathological features. Treatment options include surgical excision, radiotherapy and systemic therapy. Conclusion DS‐DFSP in the breast is extremely rare and may resemble a primary breast tumour. Surgical excision with adequate margins is recommended to achieve local disease control.