Follow-up [⁶⁸Ga]Pentixafor–PET/MRI after H pylori eradication in 4 gastric MALT lymphoma patients. (A) A 73-year-old man with marked focal gastric [⁶⁸Ga]Pentixafor uptake (SUV_max, 10.8; blue arrowheads) rated as non-CR on PET/MRI. H&E stain confirms residual disease; roughly 85% of lymphoma cells show strong cytoplasmic and membranous reactivity with CXCR4 (original magnification ×100). (B) A 57-year-old man with masslike moderate gastric [⁶⁸Ga]Pentixafor uptake (SUV_max, 6.4; blue arrowheads) rated as non-CR on PET/MRI. H&E stain confirms residual disease; ∼50% of lymphoma cells are weakly CXCR4⁺, showing dotlike paranuclear positivity (original magnification ×200). (C) A 73-year-old man with mild diffuse [⁶⁸Ga]Pentixafor uptake (blue arrowheads), rated as CR on PET/MRI. However, H&E stain shows minor residual disease; ∼30% of lymphoma cells are weakly CXCR4⁺, again showing mostly paranuclear dotlike stainings (original magnification ×200). (D) A 49-year-old woman without increased [⁶⁸Ga]Pentixafor uptake (arrowheads), rated as CR on PET/MRI. H&E stain confirms CR according to GELA criteria with focal complete intestinal metaplasia (original magnification ×100).