Hilus cell heterotopia accompanying bilateral ovarian serous cystadenomas: a case report and review of the literature.

Hilus cell heterotopia is the presence of normal hilus cells in an abnormal site. It is rare and there are only a few case reports or case series. It has been reported in the fimbrial stroma of the fallopian tube, paratubal cyst wall and beneath ovarian capsule. Most cases are more than 40 years of age, and some of them are associated with other underlying pelvic pathology. Hilus cells are ovarian counterpart of testicular Leydig cells, carrying similar morphological and immunohistochemical findings. In this report, we described a patient having bilateral serous cystadenomas with an incidental finding of hilus cells in the fallopian tube.