Solitary fibrous tumors of the soft tissues: imaging features with histopathologic correlations

Abstract

PurposeTo describe the imaging features of soft tissue solitary fibrous tumors, with histopathological correlations and clinical outcome.Material and methodsTwenty-seven patients with histologically proven SFTs were retrospectively evaluated. Imaging studies included six radiographs, five U/S studies, eighteen CT scans, fourteen MRI exams, and one angiography.ResultsOn CT scans, two lesions were isodense and five were mildly hypodense compared to muscle while 11 lesions appeared heterogeneous-mixed of iso and hypodense areas. Heterogeneous enhancement was depicted in 13 lesions and four lesions enhanced homogeneously. Six lesions were partially calcified. On T1W MR images, seven lesions were isointense and one was slightly hyperintense relative to adjacent muscles while five lesions appeared heterogeneous-mixed of iso and hypointense areas. T2W images showed high SI in two cases and heterogeneous-mixed in seven cases. Enhancement was heterogeneous in six and homogeneous in four lesions. Patchy unenhanced areas (on CT and T1W MR images) along with patchy areas of low to markedly high SI on T2W images were depicted in 19 lesions. The enhanced portions correlated to areas of increased vascularity and cellularity. The four clinically more aggressive lesions could not be predicted on imaging.ConclusionTypical soft tissue SFTs are deep masses made of isodense and isointense areas relative to adjacent muscles mixed with hypodense and hypointense areas on unenhanced CT and MR T1W respectively. Variable enhancement patterns and mixed to high signal intensities on MRT2W are attributed to tumor’s cellularity, vascularity, collagen distribution and/or degeneration. Heterogeneity of SFTs affects imaging features on MRI and CT modalities. The biological behavior of soft tissue SFTs can not be predicted based solely either on histopathologic or imaging evaluation.

Extrapleural Solitary Fibrous Tumor (SFT) at Dorsum Foot - A Rare Case Report

“…[1] Positivity for CD34, bcl-2 and CD99 indicate SFT. [3,4] In our case, tumor showed positivity for CD34 and CD99. Behaviour of SFT is unpredictable.…”

“…[1] It usually occurs in the pleura, but extra-pleural sites are also reported. [1][2][3][4] Occurrence at extra-pleural sites is rare and soft tissue sites account for 0.6% of all soft tissue tumors. [4,8] Extra-pleural sites include sub-cutaneous or deep soft tissue of extremity, head and neck, mediastinum, retroperitoneum, etc.…”

“…[1] Like pleural SFT, extra-pleural SFT are usually benign, but 10% recur locally or metastasize. [4,7] .…”

Variable Solitary Fibrous Tumor Locations

“… 17 Still, CT and MRI features of SFTs are nonspecific, revealing well-defined and often lobulated soft tissue space-occupying masses that displace adjacent anatomic structures. 18 , 19 For our 20 cases, 12/20 patients with SFTs who were diagnosed in our single hospital were located in extrapleural sites (60%). SFTs of different sizes had different features according to CT and MRI.…”

Neurocutaneous Melanosis in a Woman with Multiple Brain Melanocytomas, Cutaneous Melanocytosis and Oral Involvement

“…Similarly, in 2005 Burstein et al reported that if two-thirds of patients with NCM have giant congenital melanocytic nevi, the remaining onethird have numerous lesions but no giant lesions (3). Generally NCM diagnosis is made in the first two years of life, but very rarely some adult cases are reported in the literature such as the patient described by Zhang et al in 2008 and others (18)(19)(20)(21).…”