Solitary fibrous tumor: an update on the spectrum of extrapleural manifestations

Abstract

Solitary fibrous tumor (SFT) is a rare tumor initially believed to be a benign localized pleural tumor of mesothelial origin. Over the past few years, the literature on this tumor has grown tremendously. The tumor is now reported in diverse bodily locations, and recognized to have a wider range of clinical and radiological features. The most common extrapleural sites of the tumor are the orbits and the extremities. Tumors are often well-circumscribed masses, and vary in size from 1 cm to over 30 cm. The admixture of histological components in the tumor, namely, fibrous tissue, cellular components, and highly vascularized areas consisting of numerous closely packed small to medium-sized blood vessels, influence the imaging appearances of the tumor. On magnetic resonance imaging (MRI), the diagnosis of solitary fibrous tumor is suggested by a well-circumscribed mass that has smooth margins, and focal or diffuse hypointense signal on T2-weighted imaging due to fibrous content in the tumor. SFTs demonstrate strong focal or diffuse contrast enhancement due to the highly vascularized areas in the tumor.

Extrapleural Solitary Fibrous Tumor of Foot: A Case Report

“…Contrast enhanced MRI shows heterogeneous in as many as 82% of extrapleural SFT cases, and homogeneous enhancement effect in approximately 18%. 16,18,19 In our case, the mass showed very low signal intensity on T2-weighted image. This peculiar aspect could be the result of 30 years of exerted compression on the extrapleural SFT which may have cause hemorrhage, reactive fibroplasia, and/or calcification.…”

“…Moreover, the differential diagnosis of extrapleural SFT includes fibromatosis, myofibroblastoma, metastasis of spindle cell carcinoma, low-grade fibromyxoid sarcoma and hemangioma. 16 Clinical and imaging features of extrapleural SFTs also overlap with other fibrous tumors such as fibrous histiocytoma, fibrosarcoma and synovial sarcoma. These entities exhibit a dense fibrocollagenous matrix that can produce low signal intensity on T2-weighted MRI images, similar to extrapleural SFT.…”

“…In addition, many authors reported that the majority of these tumors (80%) showed hypointense or isointense on T1-weighted image relative to muscle, and hypointense on T2-weighted image. [12][13][14][15][16][17][18][19] On the other hand, Shin JH et al 20 reported that the extrapleural SFT in the buccal space showed hyperintense on T2-weighted image. Contrast enhanced MRI shows heterogeneous in as many as 82% of extrapleural SFT cases, and homogeneous enhancement effect in approximately 18%.…”

“…12,15, 16 Musyoki FN et al 16 highlighted the orbits and the extremities (proximal extremities muscles and subcutaneous tissues) as the most common extrapleural SFT extrapleural location. Despite that, foot and ankle involvement is even less described.…”

Management of solitary fibrous tumors localized in extremity: case series and a review of the literature

“…[8] It is a vascular originated tumor just like hemangioma and hemangiopericytoma. [9] Despite the fact that SFTs are localized to pleura and other serosal surfaces in general, they may nest in extrapleural soft tissues rarely.…”