Introduction: Ovarian metastases (OM) of breast cancer (BC) can occur with different rates, ranging from 3-30%, being reported after prophylactic, therapeutic ovariectomies or discovered at necropsy. The aim of the study was to review the histopathological aspects of 59 laparoscopic oophorectomies performed in our Department as part of the oncological treatment of premenopausal women with BC. A number of eight (13.55%) patients were histologically confirmed with OM. The initial tumor, node, metastasis (TNM) stage of BC tumors was advanced with no pelvic symptoms or imaging abnormalities associated. Five (62.5%) patients had unilateral ovarian involvement and three (37.5%) bilateral, two of them being associated with primary bilateral BC. The immunohistochemical markers used to confirm the breast origin of metastasis were estrogen receptor (ER), progesterone receptor (PR), gross cystic disease fluid protein 15 (GCDFP15), Wilms' tumor 1 (WT1), cancer antigen-125 (CA-125), cytokeratin 7 (CK7), cytokeratin 20 (CK20). One case showed positive cytoplasmic reaction for thyroid transcription factor-1 (TTF-1). GCDFP15 was positive in all OM and almost all (seven of eight) were noted as non-immunoreactive for WT1. Although six cases of metastatic BC were positive for CK7 and negative for CK20, only four of them retain the same immunoprofile of their primary tumor for the metastatic ovarian lesions. Only one case out of eight showed weak and focal positivity for CA-125. Three cases were positive for mucin 1 (MUC1) and epithelial membrane antigen (EMA).
Conclusions: The differential diagnosis between OM and primary ovarian cancer can be challenging for the pathologist as well and immunostaining is of help. GCFDP15 is the most specific for breast carcinoma. In contrast with the recent papers published in the literature, we detected TTF-1 cytoplasmic expression in invasive breast carcinoma by SPT24 clone.