Most occur in adult women, with ~66% in postmenopausal women. Although they account for ~1% of all ovarian tumours 5, they are the most common benign solid ovarian tumour. It represents <2% of paediatric ovarian tumours.
The thecoma component of a fibrothecoma can secrete oestrogen, and the patient may present with abnormal vaginal bleeding and endometrial hyperplasia.
They may be seen as a homogeneous hypoechoic mass with posterior acoustic shadowing, although in most cases the sonographic appearance is nonspecific.
The vast majority (~80%) of ovarian fibrothecomas appear as solid masses with a delayed accumulation of contrast medium. On dynamic CT, there is an absence of arterial vessels and absence or slight early uptake of contrast enhancement 3. Calcification may be present and, as these tumours enlarge, myxoid or cystic degeneration may occur, resulting in a heterogeneous pattern 4.
Reported signal characteristics include 1:
- T1: typically shows homogeneous low signal intensity
- lesions show predominantly homogeneous low signal intensity (from fibrous components)
- scattered high signal areas may be present representing areas of cystic degeneration +/- oedema
Treatment and prognosis
Most cases are benign and surgical resection is curative.