Clinicopathological and Imaging Characteristics of EBV Positive Inflammatory Follicular Dendritic Cell Sarcoma

Objective EBV-positive inflammatory follicular dendritic cell sarcoma (EBV + inflammatory FDCS) is a rare tumor that has been less systematically studied. This study aims to improve the understanding of EBV + inflammatory FDCS by analyzing radiological imaging data and clinicopathological features. Methods A retrospective analysis was performed on twelve patients with EBV + inflammatory FDCS confirmed pathologically. Ten patients underwent computed tomography (CT) scans, six underwent magnetic resonance imaging (MRI) scans, and four patients underwent CT and MRI scans simultaneously. Results Twelve patients (six in the liver and six in the spleen) had clinically asymptomatic or asymptomatic, and six cases were found on physical examination. Pathologically, the tumor cells dispersed in a background of inflammatory cells. All cases showed positive expression of at least one follicular dendritic cell (FDC) marker and EBV. On unenhanced CT images, nine cases of EBV + inflammatory FDCS presented as well-defined iso-or hypodense masses, and one liver case had an irregularly shaped lesion with unclear borders. All cases showed iso-or hypodensity signals on T1WI and mixed signals on T2WI. The hepatic lesions showed marked enhancement in arterial phase and diminished enhancement in portal vein phase and delayed phase, whereas the splenic lesions showed mild enhancement in arterial phase and continued enhancement in portal vein phase and delayed phase . Conclusion EBV + inflammatory FDCS is a rarely low-grade malignant tumor, which exists the possibility of local lymph node metastasis and recurrence. Therefore, the preoperative diagnosis is expected to improve by carefully analyzing the imaging features and clinical characteristics of the patients.