Acute pancreatitis revealing duodenal papilla MALT lymphoma: a case report and review of the literature.

Mucosa-associated lymphoid tissue (MALT) lymphoma is a rare subtype of non-Hodgkin lymphoma, predominantly found in the gastrointestinal tract, particularly the stomach. However, its localization at the ampulla of Vater is exceptionally rare and presents considerable diagnostic challenges. This atypical presentation can easily mimic more common conditions, such as ampullary tumors or pancreaticobiliary disorders, making accurate diagnosis and management particularly complex. We present the case of a 70-year-old woman who initially presented with obstructive jaundice and acute pancreatitis, ultimately revealing a diagnosis of MALT lymphoma at the duodenal papilla. She was managed with combination of Helicobacter pylori eradication therapy followed by chemotherapy. This case emphasizes the importance of considering lymphoproliferative disorders in the differential diagnosis of biliary obstruction and pancreatitis, highlighting the need for heightened awareness among clinicians. Through this unique case, we aim to contribute to the limited literature on MALT lymphoma at the ampulla of Vater, illustrating both the complexities of diagnosis and the potential for successful management strategies in rare gastrointestinal lymphomas.