Diffuse Large B-Cell Lymphoma Presenting as a Pancreatic Mass

Abstract

Primary lymphomas of the gastrointestinal tract are rare; however is the most common site of extranodal involvement. When presenting as a primary lesion, a distinction from an epithelial malignancy is critical given the difference in therapy and prognosis. Primary pancreatic lymphomas represent cancer. On physical exam, he looked chronically ill, had pale conjunctiva, tenderness to palpation in epigastric area,and palpable inguinal lymphadenopathy. Initial CBC, chemistries and liver function tests were unremarkable. LDH was elevated and CA19-9 level was normal. An abdominal CT revealed a pancreatic tail mass measuring 3.1 x 2.3 cm associated with duodenal wall thickening, peripancreatic, supraclavicular, mediastinal and inguinal lymphadenopathy. Also, a cardiac intraventricular mass that measured 6.3 x 4cm was seen occluding almost all the right ventricle.Important to note is that the liver was unremarkable. A PET CT scan showed multiple FDG-avid lesions including the pancreatic tail and cardiac masses, with a foci of highest tracer uptake near the duodenum. An ultrasound guided biopsy of a neck nodule for immunohistochemistry showed large cells with vesicular nuclei and prominent nucleoli; the cells stained positive for CD20, CD45, suggesting diffuse large B-cell lymphoma (DLBCL). He received rituximab,cyclophosphamide, doxorubicin, vincristine, prednisone, and entecavir.Figure: Pancreatic tail mass approximately 3.1 x 2.3cm.Figure: There is a foci of severe high tracer uptake of the pancreas.Figure: Multiple hypermetabolic lesions are evident.After completion of first course, he was discharged home. While at home he developed gastrointestinal bleeding that required hospitalization. At that time and while his performance status declined, he refused further treatment. This case shows that a distinction between DLBCL and pancreatic adenocarcinoma is challenging but extremely important since treatment and prognosis are very different. This patient presented with abdominal symptoms and radiologic evidence of a pancreatic mass with regional and distant lymphadenopathy initially suggesting a primary pancreatic neoplasm. However, the absence of liver metastases, B symptoms, cardiac involvement and the extensive lymphadenopathy suggested a lymphoproliferative disease. The early suspicion of this rare presentation of Non-Hodgkin's lymphoma involving the pancreas, duodenum and right ventricle helped establish timely and appropriate therapy given the high mortality associated with this disease.