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.