Malignant ovarian tumours are diagnosed at an advanced stage in the majority of cases. However, only a small percentage present as extra-abdominal, non-lymph-node solid metastases, as in the breast, and they are usually cases of relapse. The discovery of mono- or bilateral breast lesions with peritoneal carcinosis and/or abdomino-pelvic lesions can be cumbersome in the differential diagnosis of primary tumours. This article aims to summarize current evidence on the detection of breast metastases at diagnosis of ovarian cancer.
A systematic review of the literature in Scopus, PubMed/MEDLINE, ScienceDirect and the Cochrane Library, including case reports and case series, was undertaken. Data regarding study features; population characteristics; clinical, radiological and histological assessment of the disease; treatment and follow-up were collected. In addition, a case report of a patient managed at the authors’ centre is provided.
According to the search strategy, 16 articles (18 patients) were included in this review. Serous ovarian, fallopian tube or primary peritoneal cancer was detected in 61% of cases, while another type or a non-specified type of epithelial ovarian cancer was detected in 27.7% of cases; there was one case with granulosa cell tumour of the ovary and one case with mucinous ovarian tumour of low malignant potential. Breast metastases were mainly monolateral (66.6%), with other extra-abdominal sites of disease in the majority of the cases. A minority of patients (16.6%) received treatment for primary breast cancer with a subsequent diagnosis of ovarian cancer. Concomitant breast and abdominal surgery can be an option. PAX8, WT1 and CA125 immunohistochemical staining can aid in differential diagnosis.
Breast metastases of malignant ovarian tumours must be promptly recognized to ensure proper treatment. Specific immunohistochemical analysis can be a decisive assessment in uncertain cases.

Copyright © 2020 Elsevier B.V. All rights reserved.