Primary pancreatic lymphoma masquerading as pancreatic carcinoma: A case report and literature review

RATIONALE: Primary pancreatic lymphoma (PPL), representing 0.5% of pancreatic malignancies, poses diagnostic challenges due to overlapping clinical and imaging features with pancreatic adenocarcinoma. PPL is diagnosed by obtaining tissue samples via endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) or explorative laparotomy with biopsy. The R-CHOP regimen is the first-line chemotherapy protocol. This report presents a case initially misdiagnosed as pancreatic cancer, highlighting the critical role of histopathological confirmation. PATIENT CONCERNS: A 55-year-old man presented with left upper abdominal pain for 20 days. DIAGNOSES: Computed tomography, magnetic resonance imaging, and fine needle biopsy suggested pancreatic cancer or neuroendocrine tumor. Postoperative pathology confirmed primary pancreatic lymphoma. The tumor was classified as CD20(+), BCL6(+), BCL2(+), and Ki-67(+, 60%). INTERVENTIONS: The patient underwent laparoscopic distal pancreatectomy with splenectomy, followed by 6 cycles of R-CHOP chemotherapy. OUTCOMES: No recurrence was observed during a 2-year follow-up period. LESSONS: This case highlights the diagnostic challenges associated with PPL and underscores the importance of histopathological confirmation for ambiguous pancreatic lesions. Although the role of surgery in localized disease requires further investigation, the R-CHOP regimen appears to be effective for managing PPL.