Fig. 1

CT scans revealing an iso-low density mass in the spleen (A). A large number of diffuse non-caseous epithelioid granulomas in the tumor (B. H&E stain, 100x). A large number of diffuse non-caseous epithelioid granulomas in the tumor. HE, Medium magnification (C. H&E stain, 200x). Tumor cells are scattered. As indicated by the arrows, the tumor cells display mild cytologic atypia, with nuclei exhibiting a short spindle-shaped or oval morphology. The nuclear membranes are smooth and clear, and the chromatin appears vacuolar with visible small nucleoli. Additionally, mitotic figures are relatively rare (D. H&E stain, 400x). The cell membrane of tumor cells exhibits a positive reaction for CD23 (E. EnVision method, 400x). EBER positive positivesignals, as revealed by in situ hybridization, under high magnification (F. In situ hybridization method, 400x)