Sonographic diagnosis of paraovarian cysts: value of detecting a separate ipsilateral ovary

The purpose of this study was to determine the frequency with which sonographic detection of a normal separate ipsilateral ovary enables the diagnosis of paraovarian cysts.

We reviewed the initial sonographic reports, sonograms, and medical records of 42 patients with surgically proved paraovarian cysts. All sonograms were obtained with a 3.5-MHz transabdominal probe. The location, size, shape, wall thickness, internal echoes of the cyst, and visualization or nonvisualization of the ipsilateral ovaries were recorded during sonographic examination.

Forty-six paraovarian cysts were identified in 42 patients. One patient had bilateral cysts, and one had multiple (four) unilateral cysts. A teratoma in one patient and an ovarian cyst in another coexisted with a paraovarian cyst in the same adnexa. With the exception of these two, 31 (76%) of 41 ovaries abutted by cysts were detected. All detectable ovaries were normal. With one exception, all cysts were thin walled and unilocular, and 43 of 46 were anechoic. During surgery, two patients were found to have cyst torsion, two were found to have papillary serous cystadenoma, and one was found to have both.

Unlike the findings of previous reports, our results indicate that most patients with paraovarian cysts have a separate, normal ipsilateral ovary that can be detected easily by means of transabdominal sonography, thus aiding in distinguishing paraovarian from true ovarian cysts.