Pancreas Involvement of Extranodal Natural Killer/T-Cell Lymphoma, Nasal Type, Presenting as Acute Pancreatitis: A Case Report

Background: The main etiology of acute pancreatitis includes biliary origin and alcohol, although various other causes include drugs (i.e., L-asparaginase) or malignant tumors. Since accurate identification of etiologies is crucial for determining therapeutic planning, the assessment of cause should be performed as early as possible. Case presentation: A 57-year-old Korean man was admitted for chemotherapy. The patient did not drink alcohol for religious reason. 26 days prior to admission, a 4 cm-sized testicular mass was observed in ultrasound and he received right radial orchiectomy. Extranodal natural killer/T-cell lymphoma, nasal type, was diagnosed. After confirming no additional abnormal findings, chemotherapy (using the regimens Dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide) was begun. On Day 8 of chemotherapy, L-asparaginase was started and he complained of sudden onset epigastric pain after 2 days. Acute pancreatitis was diagnosed and, in order to determine if the acute pancreatitis occurred due to L-asparaginase or pancreas involvement of extranodal natural killer/T-cell lymphoma, endoscopic ultrasonography guided fine needle biopsy was performed and observed diffusely infiltrated tumor cells. Therefore, he was given a final diagnosis of acute pancreatitis due to pancreas involvement of extranodal natural killer/T-cell lymphoma, nasal type. Discussion: Acute pancreatitis caused by pancreas involvement of extranodal natural killer/T-cell lymphoma, nasal type, is a very rare disease but can occur during chemotherapy. To identify the cause of acute pancreatitis, endoscopic ultrasonography guided fine needle biopsy can be considered.