Benign pelvic masses masquerading as adnexal cancer during pregnancy on ultrasound: A retrospective study of 5 years.

This study was conducted to investigate the sonographic characteristics of benign adnexal masses misdiagnosed as malignancy, and determine whether sonographic findings may help distinguish these lesions from malignant tumors during pregnancy at a single center. We herein present our experience with pregnant women with benign adnexal masses misdiagnosed as malignancy by ultrasound and operated on during pregnancy or after delivery. A total of 4 cases of benign pelvic masses were misdiagnosed as adnexal cancer over a 5-year period, including an ovarian theca cell tumor with luteinization, an obsolete ectopic pregnancy of fallopian tube, an ovarian mature teratoma with abundant nervous tissue and a uterine myoma with degeneration. The masses were characterized by abundant blood flow and heterogeneous echo on ultrasound. In conclusion, adnexal masses identified during pregnancy exhibiting abundant blood flow and heterogeneous echo may not represent malignancy, even in the presence of increased carbohydrate antigen 125 levels. In certain cases, benign adnexal masses may be initially misdiagnosed as malignant during pregnancy.