Incidental finding of multiple diffuse large B-cell lymphomas masquerading as jejunojejunal intussusception with unexplained pleural effusion: a case report.

Primary non-Hodgkin's lymphoma of the gastrointestinal (GI) tract is rare. It is aggressive and necessitates early diagnosis and management. Simultaneous primary GI lymphomas are unusual with rarely reported cases. Case presentation: This novel case report describes an 84-year-old man with multiple primary diffuse large B-cell lymphomas (DLBCLs) of the jejunum with disseminating pleural and multiple regional lymph nodes involvement presenting as intestinal obstruction and segments of jejunojejunal intussusception. The patient underwent surgical intervention and adjuvant chemotherapy. Unfortunately, the patient suffered from multiple organ failure and died 4 months after surgery. Clinical discussion: Obstruction and perforation are rare and life-threatening complications of GI lymphoma. Multiple DLBCLs of the jejunum are rare. Moreover, primary GI-DLBCL that initially presents with pleural effusion or with intestinal perforation is uncommon. This report aims to remind clinicians that lymphoma should be considered when assessing the cause of unexplained pleural effusion, especially when the available examination data cannot be confirmed by clinical manifestations. Conclusion: Through this case report, the authors learn that clinical manifestations, morphological characteristics, immunophenotypes, and molecular biological characteristics are vastly different and important. This poses the biggest challenge before surgery and should not be ignored.