Intracystic papillary carcinoma(IPC) of the breast is a distinctive and very rare variant of intrductal carcinoma. The cytologic features of IPC have been rarely reported, and there are difficulties in distinguishing between benign and malignant papillary breast lesions.
Herein we report a IPC of the breast in a 80 year-old female. Fine needle aspiration cytology revealed monotonous cuboidal epithelial cells in small clusters and individually scattered on bloody background. The tumor cells did not show overt cytologic atypia. With the histologic features of this case and review of the literature, the cytologic differential points are discussed.