An Unusual Case of Synchronous Primary Pancreatic Lymphoma and Chronic Myeloid Leukemia

Abstract

Purpose: Background: Non-Hodgkin's lymphoma occurring concurrently with chronic myelogenous leukemia (CML) is rare. Primary pancreatic lymphoma (PPL) is an even rarer type of extranodal non-Hodgkin's lymphoma originating from the pancreas. We report a unique case of de-novo pancreatic lymphoma developing synchronously in a patient on treatment for chronic myeloid leukemia. Case: A 61-year-old male presented with 2 weeks of abdominal pain, fatigue and weight loss of 10 lbs. Three days earlier, he developed darkening of his urine and vomiting. Three years prior, he was diagnosed with obstructive jaundice and found to have a pancreatic head mass which consisted mostly of inflammatory cells on fine needle aspiration (FNA) biopsy. He was managed conservatively with antibiotics and the mass resolved. Two years later, he was diagnosed with chronic myelogenous leukemia in accelerated phase and had achieved remission on Imatinib therapy. His physical examination was unremarkable. Labs were notable for elevated total bilirubin (2.8 mg/dl), aspartate transaminase (163 IU/L), alanine transaminase (218 IU/L) and alkaline phosphatase (468 IU/L). A computed tomography (CT) of the abdomen showed a 7.7 cm hypodense mass in the head of the pancreas with vascular encasement, peripancreatic mesenteric lymphadenopathy and extrahepatic ductal dilatation. CA 19-9 and CEA were within normal limits. An endoscopic ultrasonography confirmed a pancreatic head mass and FNA was consistent with a malignant lymphoma of follicle center origin with a clonal population of B lymphocytes. Discussion: Extranodal non-Hodgkin's lymphomas (NHL) represent up to 30-40% of all NHL cases with the gastrointestinal tract being the most commonly involved site. Although secondary involvement of the pancreas is not uncommon and well documented, PPL is an extremely rare disease, representing fewer than 2% of extranodal malignant lymphomas and 0.5% of all pancreatic masses. To our knowledge, this would represent the second reported case of synchronous primary extra nodal non-Hodgkin's lymphoma and CML. We present this unique case of synchronous non-Hodgkin's lymphoma and CML to highlight this unusual combination and to emphasize the diagnostic challenges posed by evaluation of pancreatic masses. It is equally important to maintain a low index of suspicion for lymphomatous involvement of the pancreas in middle-aged adults as the treatment and prognosis differs from adenocarcinoma.