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 breast-conserving 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 breast-conserving 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). Fine-needle 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.