Fat-forming variant of solitary fibrous tumour of the pleura: CT findings

Abstract

The fat-forming variant of solitary fibrous tumour (SFT) was previously called lipomatous haemangiopericytoma and is a rare variant of solitary fibrous tumour. It predominantly occurs in the deep soft tissues of the retroperitoneum and thigh. Only a handful of cases involving the perineum, spine, thoracic wall and pelvic cavity have been reported in the radiological literature and the fat-forming variant of SFT involving the pleura has not been previously reported. Herein, we report the CT findings of a case of the fat-forming variant of SFT involving the pleura that was treated by excision. Chest CT showed a large lobulated heterogeneous fatty mass with a multifocal enhancing soft-tissue component in the left lower hemithorax. Although rare, the fat-forming variant of SFT of the pleura should be added to the differential diagnosis of fat-containing pleural soft-tissue tumours.

Figure 1

(a) Contrast-enhanced chest CT axial image shows a well-defined, lobulated heterogeneous mass with predominant fat attenuation (asterisk). (b) Contrast-enhanced chest CT axial image caudal to (a) shows multiple soft-tissue components with enhancement (arrow) in the lower part of the tumour. (c) Coronal reconstruction image shows a large fatty mass occupying most of the left lower hemithorax. The lower and medial part of the tumour appears solid with enhancement (arrow).

Figure 2

Histopathological examination (haematoxylin and eosin stain, ×40) of the mass reveals that the tumour is composed of haemangiopericytoma-like areas admixed with areas of mature adipocytes.

Figure 3

Follow-up contrast-enhanced chest CT axial image shows a residual tumour at the pre-aortic recess.