Incidental Adnexal Masses Detected at Low-Dose Unenhanced CT in Asymptomatic Women Age 50 and Older : Implications for Clinical Management and Ovarian Cancer Screening

Purpose: To determine the prevalence, work-up, and outcomes of indeterminate adnexal masses identified at low-dose unenhanced computed tomography (CT) in asymptomatic women age 50 and older undergoing colonography screening. Materials and Methods: This study was institutional review board approved and HIPAA compliant. Informed consent was waived. The fate of indeterminate adnexal lesions identified at unenhanced CT in 2869 consecutive women (mean age, 57.2 years; age range, 50-97 years) undergoing colonography screening between April 2004 and December 2008 was evaluated. Results: One hundred eighteen women (mean age, 56.2 years), representing 4.1% of the screening cohort, had an indeterminate adnexal mass (108 unilateral, 10 bilateral; mean size, 4.1 cm) at prospective CT interpretation. A total of 80 women underwent some combination of further imaging evaluation (n = 76) (transvaginal ultrasonography [n = 71], pelvic magnetic resonance imaging [n = 7], contrast material-enhanced CT [n = 7]) and/or surgery (n = 26). Mean serum CA-125 level in 33 women was 12.8 U/mL; levels were normal (, 35 U/mL) in 32 (97%) cases (range, 3-26 U/mL) and mildly elevated (41 U/mL) in one case. Final pathologic findings of surgically excised lesions were cystadenoma or cystadenofibroma (n = 14; 11 serous, three mucinous); nonneoplastic cysts (n = 5; two endometriomas); mature teratoma (n = 3); hydrosalpinx (n = 2); fibroma (n = 1); and benign Brenner tumor (n = 1). Three additional teratomas were diagnosed at index CT only. No ovarian cancers were prospectively identified, although four cases of ovarian cancer developed subsequent to a negative adnexal finding at CT examination during a 15-44-month interval among the remaining 2751 women. Conclusion: Incidental indeterminate adnexal lesions were relatively common at unenhanced CT (4.1%), but subsequent work-up revealed no ovarian cancers. Furthermore, a normal finding at CT was not protective against short-term development of ovarian cancer. More sophisticated risk factor assessment is needed to identify women at higher risk. (C) RSNA, 2010