MR imaging findings of mass-forming endosalpingiosis in both ovaries: a case report.

A 50-year-old postmenopausal woman, who underwent ultrasonography at a periodic medical checkup, was found to have bilateral ovarian masses. Pelvic magnetic resonance imaging (MRI) showed bilateral multilocular cystic ovarian masses. The cyst walls and septal structure demonstrated contrast enhancement. She underwent bilateral salpingo-oophorectomy. Microscopic examination revealed that the cysts were lined with cuboidal or columnar epithelial cells, and some of the cells were ciliated. The final histopathological diagnosis was endosalpingiosis. Endosalpingiosis is defined as the presence of ectopic ciliated epithelium, resembling the normal endosalpinx, without endometrial stroma. It rarely presents as a tumor-like mass on MRI.