Virilizing tumors of the ovary: imaging features

Virilizing tumors of the ovary are an uncommon cause of a common clinical problem. The reported imaging features of these tumors are based on case reports. The purpose of this study was to determine the spectrum of imaging characteristics of these tumors based on a larger referral population.

Case records from the Armed Forces Institute of Pathology were searched for clinical evidence of virilization as a presentation of an excised sex cord-stromal and steroid cell ovarian tumor. Records and imaging studies on 14 patients with virilizing tumors were found. All available imaging studies (ultrasound studies of the pelvis (11 patients), CT scans of the pelvis (five patients), MRI examinations of the pelvis (two patients), and plain films of the pelvis (four patients) were reviewed by three radiologists independently for ascites, calcification, percent solid portion, echogenicity and attenuation.

On CT and/or ultrasound most (69%) of the tumors appeared to be solid or mostly solid. The amount of solid tissue varied with the tumor type, granulosa cell tumors were predominantly cystic. The masses were isoechoic (82%) or hypoechoic (18%). Ascites was an infrequent (23%) finding. Only a minority of these tumors (14%) were calcified on imaging studies. Six tumors were 5.0 cm or less in mean size, and two less than 3.0 cm in size. All cases were stage I tumors at presentation.

The majority of virilizing tumors of the ovary are typically solid, noncalcified, confined to the ovary at presentation, and not associated with ascites. Variability in appearance depends in part on tumor type. Many are small and may be difficult to recognize as a mass morphologically.