Primary breast angiosarcoma with diagnostic pitfalls and management challenges

Primary breast angiosarcoma is an uncommon, aggressive vascular tumour that poses diagnostic difficulties due to overlapping clinical, radiological and histological features. We describe a patient who presented with a painless breast lump where initial cytology suggested ductal carcinoma, and core needle biopsy showed fibroadenoma. Immunohistochemistry (IHC) confirmed angiosarcoma. She underwent a mastectomy with axillary dissection. Final histopathology showed a poorly differentiated angiosarcoma with negative margins and no nodal involvement. Adjuvant radiotherapy (intensity-modulated radiation therapy with active breathing control, 66 Gy in 33 fractions) was delivered, and adjuvant chemotherapy was not administered after tumour board discussion. At 2 years follow-up, she remains disease free. This case underlines the potential for diagnostic misclassification, the importance of IHC for accurate diagnosis and the value of multidisciplinary management in achieving favourable outcomes.