Jejunal Metastasis Colliding with a Borderline Tumor in the Ovary: A Hitherto Unreported Eventuality

Metastatic adenocarcinomas to the ovary can show morphologically innocuous areas simulating primary benign lesions or borderline tumors. Ruling out a metastasis can be a difficult issue for pathologists, especially when facing with cystic tumors. Because of the important clinical implications of differentiating metastatic adenocarcinomas from primary ovarian tumors, the integration of clinical, pathological, and immunohistochemical features is warranted, primarily in case of mucinous adenocarcinomas. Vice versa, the synchronous presence of a metastasis and a primary in the same ovary is virtually excluded as a very unlikely eventuality. Here, we describe a case of metastatic adenocarcinoma from the jejunum colliding with a seromucinous borderline tumor in the same ovary, an unreported eventuality so far.