The frequency and significance of adnexal lesions incidentally revealed by CT

This paper describes the frequency of incidental adnexal findings revealed by routine CT scanning and determines the significance of these lesions in premenopausal and postmenopausal women, particularly in those with an already known malignancy other than ovarian carcinoma.

A computerized search of all radiology reports from 1992 identified 3448 women who underwent abdominopelvic or pelvic CT scans for an indication other than ovarian carcinoma or a known or suspected pelvic mass. Patients were divided into two subgroups: premenopausal and postmenopausal. CT reports were reviewed to identify patients with incidentally discovered adnexal lesions. Imaging characteristics and lesion size were recorded. To determine the significance of the lesions, we also reviewed clinical, radiologic, and histopathologic data. Lesions were judged to be benign on the basis of 12-month clinical follow-up, additional imaging that revealed stability or resolution, or histopathology. Lesions were judged to be malignant on the basis of progression of the lesion on subsequent imaging or histopathology. Lesions were classified as undetermined in patients with a serious or life-threatening illness who consequently underwent no further evaluation of the lesion.

An incidental adnexal lesion was revealed by CT scanning in 168 cases (5%). Seventeen of these patients were lost to follow-up. Of the remaining 151 patients, 104 (69%) had incidental adnexal lesions that represented benign disease, 45 (30%) had undetermined lesions, and two (1%) had malignant lesions. In analyzing the two subgroups of patients, we determined that 56 (81%) of 69 premenopausal patients and 48 (59%) of 82 postmenopausal patients had benign adnexal lesions. On the basis of chart review, 67 patients had a known malignancy. Of these patients, 30 (46%) had benign adnexal disease, and 31 (48%) had undetermined findings. Four (6%) were lost to follow up, and the remaining two patients (3%) who were postmenopausal had metastatic disease of the ovaries. No primary ovarian malignancies were discovered incidentally in our study population.

Our results indicate that in both premenopausal and postmenopausal women a significant proportion of adnexal lesions incidentally revealed on routine CT scanning are benign, even in women with known malignancies other than ovarian carcinoma.