Objective: To compare clinical, ultrasonographical, and cytological findings with the histopathological diagnosis of unilocular, anechoic smooth-walled cystic ovarian tumors ('simple ovarian cysts').
Method: In 140 premenopausal women simple ovarian cysts were removed by laparoscopy following ultrasound evaluation. In this retrospective study the histopathological diagnosis was correlated with clinical data, sonographic characteristics, macroscopic impression and with cytological findings.
Results: Histopathology revealed 21 (15.0%) functional cysts, 31 (22.1%) retention cysts, 9 (6.4%) endometriomas, 3 (2.1%) cystic teratomas, 12 (8.6%) undifferentiated cysts and 64 (45.7%) cystadenomas. No mentionable differences were correlated with the patient's age or the size of the cyst as determined by ultrasound. Classically, 'chocolate-like' cystic fluid characterizes endometriomas. However, in the present study cysts with different histopathological classifications exhibited similar fluid characteristics. The cytological diagnosis was correct in only 53 (37.9%) of all 140 cases.
Conclusion: In premenopausal women differential diagnosis of ovarian cysts is not possible by clinical characterization, either by ultrasound or cytological evaluation. Simple ovarian cysts should be observed for at least 8 weeks or 2 menstrual cycles, respectively. If persisting over that period, the ovarian cyst should be removed by laparoscopy, but not by cyst aspiration.