High-Grade Breast Epithelioid Angiosarcoma Secondary to Radiotherapy Metastasizing to the Contralateral Lymph Node: Unusual Presentation and Potential Pitfall.

Background: Breast angiosarcoma is a rare disease occurring as primary tumour or secondary to lymphoedema or radiotherapy. The more frequent use of breastconserving therapy and radiotherapy for breast carcinoma explains the increasing diagnosis of these tumours. Case Report: We report a case of a breast epithelioid angiosarcoma which metastasized to the contralateral axillary lymph node, occurring 4 years after breastconserving therapy with axillary lymph node dissection and radiotherapy. The patient presented skin lesions and an axillary lump (clinically diagnosed as carcinoma relapse and lymph node metastasis). Fineneedle cytology on both lesions and a core needle biopsy of the axillary lump were carried out. Differential diagnosis included carcinoma, malignant melanoma, and angiosarcoma. Immunohistochemistry confirmed the diagnosis of angiosarcoma. Conclusions: Breast angiosarcoma is a challenge – clinically, radiologically and pathologically – and requires a high index of suspicion in susceptible patients.