The 'simple' ovarian cyst: aspirate or operate?

One hundred ultrasound-guided ovarian cyst punctures were performed in 88 patients. To minimize the risk of unexpected malignancy, only persistent or painful cysts less than 10 cm in diameter were aspirated, cysts with solid areas or multiple locules were excluded. Cytological diagnosis was not possible in 72 of the 100 fluids; of the others 20 contained cells suggestive of follicular or luteal cysts, four samples suggested endometriosis and four benign tumours of epithelial origin. Oestradiol levels were high in 54 cystic fluids, and a combination of oestradiol estimation and cytology facilitated the identification of a follicular origin. Most such patients would normally have undergone surgery, but this was eventually required in only 10 of 60 in whom the cyst fluid was clear or slightly blood-stained and in 16 of the 28 with heavily blood-stained fluid. Ultrasound-guided ovarian cyst puncture would appear to be a valid alternative to surgery for carefully selected benign ovarian cysts especially when the cyst is considered not to contain blood.