Journal of Radiology
Open Access

Ovarian fibrothecomas are rare tumors of sex cord-stromal origin that represent <4% of all ovarian neoplasms [1] the majority of fibrothecomas are benign. Most occur in adult women, with 66% in postmenopausal women [2].

Generally, pelvic pain or distention and irregular vaginal bleeding are the main patient symptoms [3-5]. Although the ovarian mass by itself is supposedly benign in nature, estrogenic effects, such as endometrial hyperplasia, endometrial cancer and postmenopausal bleeding, commonly accompany fibrothecomas.

The parenchyma of fibrothecomas typically exhibits homogeneous low signal intensity on T1 and T2 when compared with myometrium; abundant collagen and fibrotic content of the tumor are the reasons that these features are observed on MRI. Scattered high signal areas on T2 may be present representing areas of cystic degeneration Figure 1. A prominent Diffusion restriction should not be misinterpreted as malignant lesion. Fibrothecoma shows a mild enhancement following contrast injection. The thickened endometrium observed in postmenopausal woman may also be a valuable imaging feature.

Figure 1: PelvisMRI images of a 68 year-old woman demonstrating left ovarian fibrothecoma:
Large left ovarian solid mass, lobulated, well circumscribed and encapsulated with heterogeneous structure. T2- weighted images shows a solid heterogeneous signal mass; the central area containing abundant fibrous tissue has marked low signal intensity (arrow) and the area containing an abundant the coma component has intermediate signal intensity (arrowhead) with small cystic changes.Sagittal T2-weighted image demonstrates endometrial thickening. No hemorrhage or signs of intratumoral fat on T1. Mild homogeneous enhancement is seen in post contrast images.