Aspiration cytology of sarcomatoid carcinoma of the breast: Report of a case with cystic change.

Sarcomatoid/metaplastic carcinomas of the breast are rare breast malignancies that show a myriad of cytohistologic patterns in aspirates. These poorly differentiated invasive carcinomas contain both ductal and mesenchymal elements with transitional forms displaying either spindle, squamous, chondroid, or osseous differentiation. We describe such a neoplasm in a 68-yr-old woman, the diagnosis of which was missed at the initial fine-needle aspiration (FNA) due to cystic change. Extensive cystic change in a sarcomatoid carcinoma is unusual and is reported for the first time in the English literature.