Struma ovarii: CT findings

Background: The purpose of this study was to evaluate computed tomographic findings of struma ovarii. Methods: Computed tomography (CT) scans of 13 pathologically proven struma ovarii were retrospectively reviewed by two radiologists in consensus. Scans were evaluated for the laterality, size, mass configuration, margins, internal architecture, presence of intracystic high attenuation lesions on precontrast scans, and cyst wall enhancement. Results: The mean size of the tumors was 11.4 cm (range 4.7-21.0 cm). Mainly cystic (n = 8, 61.5%) or cystic (n = 5, 38.5%) appearance was common to all the tumors. All tumors were unilateral and had smooth margins. The most common internal architecture in the tumors was multicystic architecture (n = 11, 84.6%). Eleven tumors (84.6%) showed a high attenuation lesion in the cyst portion of the mass on precontrast scans and the attenuation ranged from 92.2 to 120.5 Hounsfield units (HU) (mean, 106.8 +/- 8.8 HU). The cyst wall showed no (n = 7, 53.8%), moderate (n = 5, 38.5%), or marked (n = 1, 7.7%) enhancement after administration of contrast medium. Conclusions: On CT scans, struma ovarii appeared most often as a smooth marginated multicystic mass with a high attenuation lesion on precontrast scans and no or moderate cyst wall enhancement.