A Pilot Evaluation of Magnetic Resonance Imaging Characteristics Seen With Primary Soft Tissue Giant Cell Tumor in 2 patients

Background: Primary soft tissue giant cell tumor (GCT-ST) is a rare tumor with low malignant potential . Here we reported two cases of patients with soft tissue giant cell tumor in the limb, including their clinical and imaging findings (conventional Magnetic resonance imaging (MRI) and Diffusion-weighted imaging (DWI)). Methods: This retrospective study included two pathology-confirmed GCT-ST patients. Plain MRI, dynamic contrast enhancement MRI (DCE-MRI), and DWI were performed with a 3.0T whole-body MR scanner before surgery. The following characteristics of lesion were recorded: signal intensity on T 1 FSPGR and T 2 WI, morphology, maximum lesion size, time-intensity curve (TIC) on DCE-MRI, and apparent diffusion coefficient (ADC) value from DWI. Results: The maximum lesion size ranged from 4.0 cm to 6.0 cm. Signal intensities of all lesions were heterogeneous on T 1 FSPGR and T 2 WI. Nodular enhancements were observed for all lesions with either oval or irregular shapes on MRI. All lesion margins were blurred, and internal enhancements were heterogeneous on DCE-MRI. TIC appeared with a slow increase in type. Lesions on DWI (b=500s/mm 2 ) were hyperintense with a higher mean ADC value of 2.19×10 −3 mm 2 /s compared to surrounding normal soft tissue (1.03×10 −3 mm 2 /s). Conclusions: MRI features of these two GCT-STs include heterogeneous signal intensity within the lesion on T 2 WI and T 1 FSPGR, nodular enhancement with blurred margins, either oval or irregular shapes, and a slow increase enhancement of TIC on DCE-MRI. DWI may be a useful tool for differentiating benign soft tissue mass from giant cell-rich soft tissue neoplasms or malignant tumors. However, these findings need to be confirmed using a higher sample study.