Sonographic features of parovarian cysts and their complications.

Parovarian cysts have received virtually no attention in the sonography literature, despite a common occurrence, constituting 10%-20% of adnexal tumorlike conditions in pathologic series. The sonographic features of 11 parovarian cysts, including a number with complications, are reported. Six uncomplicated lesions had the appearance of simple cysts found in other organs. One cyst had ruptured, and one lesion was associated with ipsilateral tubal torsion. Two cysts had echogenic areas representing blood clot. One cyst had a triangular papillation representing the development of a serous cystadenofibroma in its wall. This experience differs from previous reports in that there was increased incidence of preoperative recognition of an adnexal mass clinically, lack of identification of a fallopian tube exiting from the lateral aspect of the parovarian cyst and identification of complications sonographically, and the smaller average size of lesions, both clinically and sonographically. Parovarian cysts and their complications should be included in the differential diagnosis of cystic adnexal masses.