Ovarian Fibromatosis: Magnetic Resonance Imaging Findings With Pathologic Correlation

Ovarian fibromatosis associated with large pedunculated fibroma in a 30-year-old woman: A rare coincidence or variant?

A 30-year-old nulligravida was referred under suspicion of large subserosal myoma. T2-weighted magnetic resonance imaging revealed multilobulated solid mass in the left lower abdomen measuring 16 cm in longitudinal diameter. The ovarian surface was covered with a marked T2-hypointense thick rim called "black garland sign," forming multiple nodular masses ranging from 1 to 5 cm in diameter in some portions of the bilateral ovaries. By laparoscopic-assisted minilaparotomy, the stalk of pedunculated mass originating from the left ovarian hilum was excised, followed by carrying out of the body after in-bag morcellation using a surgical scalpel. Right ovarian exophytic nodular masses larger than 1 cm were excised using monopolar electrode needle. Pathological examination of excised right and left masses showed fibroblast-like spindle cell proliferation with collagenous stroma; however, differences between right and left masses cannot be distinguished on a histological level. Postoperative diagnosis was ovarian fibromatosis coexisting with large pedunculated fibroma.

Ovarian Fibromatosis: "The black garland sign"

The main objective in the imaging differential diagnosis of an ovarian mass is to establish whether it is cystic or solid; solid lesions are less common. Ovarian fibromatosis is a benign disease of the ovary that is rarely included in the differential diagnosis of solid ovarian lesions. Characteristic features of masses that have a fibrous component are low signal in T1-weighted MRI sequences and especially in T2-weighted MRI sequences. The presence of peripheral fibrotic tissue around the residual ovarian tissue is specific to ovarian fibromatosis; on MRI, this results in marked hypointensity on T2-weighted images that has been dubbed the "black garland sign". This sign, together with slight peripheral enhancement after the administration of contrast material and the preservation of the ovarian architecture, facilitates the diagnosis, making it possible to avoid unnecessary surgical interventions.

Ovarian solid tumors: MR imaging features with radiologic-pathologic correlation

Ovarian solid tumors have variable histological types including benign and malignant tumors. In addition, non-neoplastic lesions sometimes show a tumor-like appearance. It is important to differentiate benign from malignant tumors. In general, low signal intensity (SI) on T2-weighted imaging (T2WI), low SI on diffusion-weighted imaging (DWI), and gradual increased pattern on dynamic contrast-enhanced magnetic resonance (MR) imaging are known to be suggestive of a benign tumor. Conversely, there are some cases in which these rules do not apply. We should, therefore, strive for a greater understanding of these exceptional cases. Several tumors show characteristic findings on MR imaging reflecting pathologic features, which leads to the correct diagnosis. Additionally, MR imaging provides important information other than the nature of tumors, such as secondary uterine changes. Furthermore, clinical findings and laboratory examination data also help in determining the correct diagnosis.

Miscellaneous tumour-like lesions of the ovary: cross-sectional imaging review

Miscellaneous tumour-like ovarian lesions are histobiologically diverse, and are often mistaken for the more common ovarian cancers, leading to aggressive management. Knowledge of characteristic clinical, laboratory and imaging findings of these select non-neoplastic ovarian entities allows correct diagnoses and permits optimal management.