Fig. 4

A 46-year-old male patient with inflammatory pseudotumor (IPT)-like follicular dendritic cell sarcoma (FDCS) in the liver. a The lesion shows a slightly lower signal intensity in the T1-weighted image sequence, and the boundary is not clear. b On the T2-weighted image sequence, the lesion is slightly hyperintense, and a “halo sign” can be seen at the edge of the lesion. c The lesion shows heterogeneous hyperintense signals on the diffusion-weighted imaging sequence. d The lesion shows an obvious central nodular enhancement in the portal vein phase. e Progressive enhancement in the venous phase with relatively low enhancement at the lesion’s margin. f The enhancement of the lesion decreases in the delayed phase and a rim enhancement can be seen at the edge. g IPT-like FDCS of the liver, demonstrating abundant infiltration of inflammatory cells and the distribution of capillaries (hematoxylin and eosin [HE], ×200). h Small vessels can also be seen in the fibrous pseudocapsule of the tumor (black star; HE, ×100)