A Case of a Breast Metaplastic Carcinoma with a Giant Cyst

A 32-year-old woman was admitted to our hospital for a right breast mass. Ultrasonography showed an 8 cm cystic mass with irregular solid components in the C area. CT showed the 8 cm cystic mass in the right breast, and that the chest wall was compressed by the mass. We performed fine needle aspiration(FNA)of this cyst and prepared a cellblock from the intracystic fluid. These cytological findings were malignant. We diagnosed cancer of the right breast and performed mastectomy and axillary node resection. Histologically, this lesion was diagnosed as a mixed metaplastic carcinoma, composed of squamous cell carcinoma, invasive carcinoma of no special type, and spindle cell carcinoma. Immunohistochemically, estrogen receptor, progesterone receptor, and HER2were negative. Adjuvant chemotherapy(FEC followed by triweekly docetaxel)was administered. There have been no signs of recurrence as of 1 year after the operation.