A case report of primary pancreatic lymphoma revealed by an acute pancreatitis.

INTRODUCTION: Primary pancreatic lymphoma (PPL) is a rare malignancy. Diffuse large B-cell lymphoma is the predominant subtype, often affecting the pancreatic head in elderly males. Due to its rarity and nonspecific symptoms, PPL is frequently misdiagnosed, leading to unnecessary surgeries. This case report discusses the diagnosis and management of PPL in a 47-year-old female, emphasizing the challenges in its identification.

CASE PRESENTATION: A 47-year-old female with no medical history presented with severe epigastric pain and jaundice. Diagnosed initially as acute pancreatitis. The abdominal CT scan showed a tumor in the head of the pancreas suggesting pancreatic adenocarcinoma invading the vessels, making it minimally borderline. However, due to the presence of large intra- and retroperitoneal lymph nodes casting doubt on the diagnosis, we further investigated with an MRI and Endoscopic Ultrasound with fine-needle aspiration, which ruled out adenocarcinoma and confirmed a pancreatic diffuse large B-cell lymphoma. The patient underwent chemotherapy with CHOP, showing significant improvement after six cycles.

DISCUSSION: Primitive pancreatic lymphoma (PPL) is a rare form of non-Hodgkin lymphoma, often mimicking other pancreatic diseases. B-cell lymphomas, especially diffuse large B-cell lymphoma (DLBCL), are common in PPL. Diagnostic criteria include the bulk of disease in the pancreas, no splenic or hepatic involvement, and normal white blood cell count. Imaging modalities aid in diagnosis, but histopathological evaluation is essential. Treatment options include chemotherapy, radiation therapy, and surgery, with rituximab-based regimens being common for DLBCL.

CONCLUSIONS: B-cell pancreatic lymphoma poses diagnostic challenges due to nonspecific symptoms. A definitive diagnosis requires histopathological evidence, often obtained through minimally invasive procedures like endosonography-guided biopsy. Treatment involves chemotherapy, immunotherapy, and radiation, with early detection correlating with improved outcomes. Surgery's role is limited due to the diffuse nature of the disease. This case underscores the importance of considering PPL in the differential diagnosis of pancreatic masses, especially in atypical clinical presentations.