Mesonephric-like adenocarcinoma of the ovary in an elderly woman: A case report and a review of the literature.

Mesonephric-like adenocarcinoma (MLA) is a rare tumor that occurs in the uterine endometrium and ovary. It morphologically and immunohistochemically resembles cervical mesonephric adenocarcinoma (MA). Here, we present a case of MLA of the ovary along with a literature review. An asymptomatic 84-year-old woman presented with a pelvic mass, detected by computerized tomography. Magnetic resonance imaging demonstrated a polycystic mass with a solid component in the left adnexal region. The solid component showed low signal intensity on T2-weighted imaging and high signal intensity on diffusion-weighted imaging. We strongly suspected an ovarian malignant tumor; therefore, surgical resection of the uterus and adnexa was performed. Macroscopically, the tumor was predominantly solid with yellowish-tan cut surface. Microscopically, it showed a tubular pattern with intraluminal colloid-like material resembling MA. The tumor cells were negative for estrogen receptor, calretinin, and CD10 and positive for PAX8 and TTF-1. These findings are consistent with those of MLA.