Fine needle aspiration cytology in primary breast angiosarcoma: a case report.

Background: Angiosarcoma of the breast is an uncommon, aggressive, vascular tumor. The cytomorphologic features of angiosarcomas have rarely been reported.

Case: The present study describes a case of breast angiosarcoma initially diagnosed by fine needle aspiration cytology. Angiosarcoma appeared in the left breast of a 58-year-old woman after 12 years of a mastectomy (without radiotherapy) of the contralateral breast for invasive ductal carcinoma. Fine needle aspiration cytology yielded very bloody material with moderate cellularity. Microscopically, two types of cells were observed: spindle cells and epithelial-like cells with nuclear atypia. The latter were arranged in tight clusters with papillary configuration. Both cell types exhibited immunoreactivity for endothelial markers. The diagnosis of angiosarcoma was confirmed by histopathology of the surgically excised tumor.

Conclusion: Angiosarcoma rarely occurs in the breast, and a definitive diagnosis is extremely difficult relying exclusively on cytologic features. Predominance of epithelioid cells may suggest an epithelial tumor, especially in patients with a history of breast carcinoma, whereas predominance of spindle cells can be misinterpreted as phyllodes tumor or another type of sarcoma. Cell block immunocytochemistry and tumor cell labeling with endothelial markers are necessary for accurate diagnosis.