Well-differentiated serous ovarian carcinoma presenting as a breast mass: a case report and flow cytometric DNA study.

Ovarian carcinoma metastatic to the breast is uncommon. We report a rare occurrence of ovarian carcinoma that initially presented as a breast mass. Complete examination revealed bilateral ovarian tumors with widespread peritoneal and abdominal disease. One of the ovarian tumors was a papillary serous tumor of low malignant potential, and the other was a well-differentiated papillary serous carcinoma. Although the neoplasm within the breast resembled serous ovarian carcinoma with psammoma bodies, the initial presentation and the presence of an apparent intraductal component created a potential for its misdiagnosis as a primary breast carcinoma. Using DNA flow cytometry, we demonstrated the relationship between the breast, lymph node, and peritoneal metastases and the serous carcinoma, thereby supporting the histologic diagnoses.