Rapidly progressive EBV-positive DLBCL arising from a duodenal diverticulum

Rapidly progressive EBV-positive DLBCL arising from a duodenal diverticulum An 81-year-old man with a history of diabetes mellitus presented with hematemesis.Urgent esophagogastroduodenoscopy (EGD) revealed an adherent blood clot inside a periampullary duodenal diverticulum, suggesting diverticular bleeding ( Fig. 1 A).Since no active bleeding was endoscopically observed, conservative therapy was adopted.Five days later, follow-up endoscopy showed an apparent benign ulcer inside the diverticulum ( Fig. 1 B).Two months later, the patient recurred melena and repeat EGD demonstrated a large ulcerative lesion surrounded by irregular elevations at the same site ( Fig. 1 C).Bioptic examination revealed diffuse infiltration of large atypical lymphoid cells in the stroma.Immunohistochemistry showed CK AE1/AE3(-), CD3(-), CD20( + ), CD5(-), CD10(-), BCL2( + ), BCL6(-), MUM1( + ), and EBER( + ) ( Fig. 2 ), establi-