Ovarian hilus cell heterotopia.

A systematic pathologic study was done of the paratubal and parametrial tissues, submitted along with distal tubal segments excised for sterilization and with uteri (with or without attached adnexa) removed for common gynecologic conditions. Heterotopic ovarian hilus cell rests were noted in 12 cases, giving an overall incidence of 0.52% (12/2299). These cell rests, confined exclusively to the endosalpinx and perisalpinx, were easily differentiated from pregnancy-related decidual nodules, Walthard rests, foci of paratubal endometriosis, and ectopic adrenal rests.