24. Benign pelvic mass

Benign pelvic masses can be of uterine or ovarian origin. Benign uterine masses such as uterine fibroids usually cause additional symptoms such as abnormal vaginal bleeding (chap. 22). There are numerous types of benign cysts. Functional cysts include follicular and corpus luteum cysts. Neoplastic cysts include epithelial tumours, sex cord-stromal tumours, or germ cell tumours. The most common types are the mature teratomas, serous and mucinous cystadenomas and the ovarian fibromas. For optimal treatment of ovarian masses, accurate differentiation between a benign and malignant mass with ultrasound is indispensable. Besides subjective assessment, there are many ultrasound models available to aid the clinician with this differentiation. The most promising models are the IOTA models: logistic regression 2 (LR2) model, Simple Rules, and Assessment of Different NEoplasias in the adneXa (ADNEX) model. The decision whether to operate depends on the symptoms, the subtype, the size, the patient’s menopausal status, and whether there is doubt about the nature of the mass. If surgery is indicated, the route of surgery (laparoscopy versus laparotomy) and extent of surgery (cystectomy versus ovariectomy) should be decided.