Pseudolymphoma (reactive lymphoid hyperplasia) of the liver: A clinical challenge

Figure 1 Imaging findings of case 1. A: T2-weighted fat-saturated image showing focal mass (indicated by arrow) in segment 2 with increased signal intensity as compared to background liver; B: T1-weighted fat-saturated image showing focal mass with decreased signal intensity as compared to background liver; C: T1-weighted fat-saturated image after contrast infusion in the late arterial phase. The mass is hypervascular on this phase; D: T1-weighted fat-saturated image after contrast infusion in the portal venous phase. The mass washes out on this phase. A capsule is seen; E: Positron emission tomography scan shows hypermetabolic activity; F: T1-weighted fat-saturated image 20 min after hepatocellular contrast, Gadoxetate Disodium (Eovist) infusion. Lesion does not take up Eovist.

Figure 2 Histopathological findings of case 1. A and B: Tumoral nodule containing lymphoid proliferation characterized by reactive lymphoid follicles and interfollicular plasma cells within liver parenchyma; C: Numerous CD20 positive B cells mostly confined to follicles; D: Numerous interfollicular polyclonal CD138 and MUM-1 positive plasma cells.

Figure 3 Imaging findings of case 2. A: T2-weighted fat-saturated image showing subtle focal mass (indicated by arrow) in subcapsular portion of segment 2 with increased signal intensity as compared to background liver; B: T1-weighted fat-saturated image showing small focal mass with decreased signal intensity as compared to background liver; C: T1-weighted fat-saturated image after contrast infusion in the late arterial phase. The mass shows subtle hypervascular enhancement on this phase; D: T1-weighted fat-saturated image after contrast infusion in the portal venous phase. The mass shows faint wash-out on this phase; E: T1-weighted fat-saturated image after contrast infusion in 3 min delayed post contrast phase. The mass shows faint filling in.

Figure 4 Histopathological findings of case 2. A: Tumoral nodule within liver parenchyma; B: CD21 immunostain showing round follicular dendritic networks in follicles; C: Sections of adjacent liver parenchyma showing bridging fibrosis; D: Portal and focal lobular lymphoid aggregates with plasma cells and focal nodule formation.