Abnormal uterine cavity: Differential diagnosis with MR imaging

The objective of the study was to assess the usefulness of magnetic resonan ce (MR) imaging in distinguishing malignant from benign conditions in patie nts with an abnormal uterine cavity. Fifty-four patients that were suspecte d of having abnormal uterine cavities were retrospectively evaluated by usi ng MR imaging. The diagnosis of an abnormal uterine cavity included a thick ened endometrium, and/or a endometrial mass, and/or a submucosal mass. Thre shold values to classify the uterine cavity as abnormal on sagittal T-2-wei ghted images were >10 mm for premenopausal women and >5 mm for postmenopaus al women. Malignancy was diagnosed when lesions invaded the myometrial/junc tional zone, and/or lesion enhancement was lower than that of the adjacent myometrium. The results found that histology confirmed 18 malignant and 37 benign lesions. Twelve of 15 endometrial carcinomas and 3 malignant mixed m esodermal tumors (MMMT) were correctly characterized as malignant on enhanc ed T-1-weighted images; whereas 6 of 15 endometrial carcinomas and 3 MMMT w ere correctly characterized on T-2-weighted images. Thirty-four of 37 benig n cases were correctly characterized as not malignant on enhanced T-1-weigh ted images. One of 14 submucosal leiomyomas, one endometrial stromal metapl asia, and one of ten pathologically normal endometria were misdiagnosed on enhanced T-1-weighted images but were correctly diagnosed on T-2-weighted i mages. The overall sensitivity, specificity, and accuracy for distinguishin g malignant from benign central uterine masses were 83%, 92%, and 89% for e nhanced T-1-weighted image, and 50%, 97%, and 82% for T-2-weighted image, r espectively. We came to the conclusion that in diagnosing patients with abn ormal uterine cavity, MR imaging may help differentiate malignant from beni gn disorders, (C) 1999 Elsevier Science Inc.