Ovarian neoplasms and the risk of adnexal torsion. Previous reports examining adnexal torsion suggested that benign ovarian neoplasms are more likely to undergo torsion than malignant ovarian neoplasms. To our knowledge, this clinical observation has not been quantified. To examine this hypothesis, we reviewed our experience with ovarian neoplasms found at the time of surgery over a 10-year period. Benign ovarian neoplasms had a 12.9-fold increased risk of undergoing adnexal torsion when compared with malignant ovarian neoplasms (95% confidence interval, 10.2 to 15.9). The histologic type of ovarian neoplasm does not appear to affect the rate of adnexal torsion. Adnexal torsion rarely involves cancer. 