Radiological findings in pelvic solitary fibrous tumour

Abstract

Solitary fibrous tumour (SFT) is an uncommon, usually benign mesenchymal neoplasm. SFT was first described in the pleura, but has subsequently been reported to occur in numerous anatomic locations including the abdomen and pelvis. Abdominopelvic SFTs are typically an indolent process, in spite of reaching a large size by the time of diagnosis. The preferred treatment is complete resection followed by extended follow-up surveillance. The risk of local recurrence and metastasis correlates with tumour size and the histological status of surgical margins. We present the imaging findings of a large pelvic SFT in a 61-year-old female, including ultrasound, CT and MRI.

Figure 1.

(a) Sagittal greyscale view of the pelvis shows a predominantly solid mass (arrows) with large internal vessels as well as a large vessel (arrowheads) draping over the superior margin mass. (b) Corresponding colour Doppler view demonstrates marked flow within the large vessels. The large vessel (arrowheads) draping over the superior margin of the mass (arrows) exhibits prominent aliasing, reflecting high velocity.

Figure 2.

(a) Axial T₁ fat saturation post-contrast demonstrates a large rounded vascular mass (arrows) with central areas of non-enhancement. (b) Sagittal T₂ weighted MRI of the pelvis shows a large heterogeneous predominantly hypointense round mass (arrows) in the pelvis with numerous rounded areas which represent flow voids within prominent draining veins (arrowheads).

Figure 3.

(a, b). Axial (a) and coronal (b) contrast-enhanced CT shows an 8 cm presacral soft tissue mass (arrows) with central calcifications and hypodensity, likely reflecting central necrosis. The mass causes significant deviation of the rectum (R) to the left, better appreciated on the coronal reformat (b). Prominent draining veins (arrowheads in b) are well seen abutting the cranial aspect of the mass.