Differentiating Primary Pancreatic Lymphoma Versus Primary Splenic Lymphoma: A Case Report

Abstract

Background: Both primary pancreatic lymphoma (PPL) and primary splenic lymphoma (PSL) represent rare entities. PPL typically arises in the head of the pancreas but may arise in other locations also. PSL usually presents with nonspecific symptoms, including left upper quadrant pain, weight loss, and fever. This report describes a patient with a large left upper quadrant mass, which initially was believed to be a primary pancreatic mass, but which on final pathology appeared to be consistent with a PSL. Presentation: The patient is a 64-year-old woman who initially presented with symptoms of left upper quadrant abdominal pain and distension; she subsequently was found to have an 18 cm heterogeneous mass arising from the pancreatic tail. She underwent a distal pancreatectomy with splenectomy. Final pathology confirmed a diffuse large B cell lymphoma arising from the splenic parenchyma. Conclusions: Both PPL and PSL are rare causes of left upper quadrant masses. In this case, we describe a large lymphoma that appeared to arise from the tail of the pancreas, but on final pathology was found to be splenic in origin. Differentiating these two clinical entities is important for prognostication and treatment. A multimodal approach with surgical resection followed by chemotherapy is preferred.

Keywords: left upper quadrant mass; primary pancreatic lymphoma; primary splenic lymphoma.

FIG. 1.

Axial (A) and coronal (B) computed tomography scan showing 12 × 12 × 18 cm mass at the tail of pancreas and splenic hilum. Histological sections of the lesion show that the lymphoma invades toward pancreas without infiltrating into pancreatic parenchyma (C) (hematoxylin and eosin × 20). Sections of the spleen reveal lymphoma cells infiltrating into splenic parenchyma with extensive necrosis (D) (hematoxylin and eosin × 40). Higher magnification shows a monomorphic population of large lymphocytes (E) (hematoxylin and eosin × 400). Immunohistochemical stain showing CD5⁺ expression by lymphocytes (F).