Transvaginal sonographic appearance of hemorrhagic functional ovarian cysts and their spontaneous regression

OBJECTIVES: To obtain information on the characteristic feature of transvaginal sonograms of hemorrhagic functional ovarian cysts (HFOCs) and their natural course. METHODS: Thirty-four cases of suspected HFOC based on our tentative criteria were ultrasonically followed-up for 3 months. After the study period, the sonographic findings and their changes with time were analyzed. RESULTS: Twenty-four cases were clinically diagnosed as HFOCs, as the masses disappeared naturally. At the first examination, 5 cases (20.8%) showed a diffuse echogenic pattern which seems to consist of a blood clot, 9 (37.5%) were mixed pattern with a clearly demarcated solid part, 3 (12.5%) were hyperechoic sponge-like reticular pattern and 7 (29.2%) were cysts including vague echo inside which looked cotton-like. Seven masses (29.2%) disappeared within 2 weeks and the remaining had a different sonographic appearance with time until they disappeared finally within 8 weeks. CONCLUSIONS: HFOCs show the characteristic changes in transvaginal sonographic appearance and can be diagnosed by short-term follow-up.