Primary epithelioid angiosarcoma of the breast: A challenging diagnosis

Abstract

Breast angiosarcoma represents a rare aggressive neoplasm that constitutes less than 0.05% of all breast malignancies and less than 1% of all soft tissue sarcomas. Breast angiosarcomas are etiologically and clinically subdivided into primary and secondary angiosarcomas. Primary angiosarcoma is less common and develops at younger ages compared to secondary angiosarcoma. Epithelioid angiosarcoma is an exceedingly rare histological subtype that presents a diagnostic challenge due to morphological similarities with other malignancies. We present a case of a 66-year-old Syrian woman who presented to our hospital with a painless, palpable mass in her right breast, and no other complaints. She had undergone fine-needle aspiration cytology at another institution, by which she was diagnosed with invasive ductal carcinoma. The patient was subsequently referred to our hospital for further investigations. Physical examination revealed a mass in the inferior medial quarter of the right breast. Following detailed physical and radiological examinations, the patient underwent surgical excision of the lesion. Microscopic examination revealed a proliferation of large epithelioid cells with abundant eosinophilic cytoplasm that were forming slit-like vascular spaces. Areas of necrosis and hemorrhage were present. Immunohistochemical examinations confirmed the final diagnosis of an epithelioid angiosarcoma of the breast. This case highlights major challenges in diagnosing this rare entity in the presence of non-specific clinical and radiologic characteristics, and addresses pitfalls in cytological examinations and differential diagnostic considerations.