Masquerade without a mass: an unusual cause of severe acute pancreatitis

Abstract

After excluding the typical causes, the underlying etiology of severe acute pancreatitis is often elusive; tumors are on the differential but may be difficult to prove in the absence of a discrete mass on imaging. In this report, we describe the case of an elderly woman with diffuse large B-cell lymphoma masquerading as acute pancreatitis. To our knowledge, only twelve other cases of pancreatic B-cell lymphoma presenting as acute pancreatitis have been described. However, while other cases involved well-circumscribed tumors of the pancreas, this is the first known case of pancreatic lymphoma of a diffusely infiltrating pattern presenting as acute pancreatitis.

Keywords: Pancreatitis; lymphoma; pancreatic.

Figure 1

Computed tomography (CT) of the abdomen and pelvis demonstrating severe pancreatitis without an obvious focal lesion (Figure 1A), as well as developing pseudocysts and nonspecific upper abdominal and right retrocrural lymphadenopathy (Figure 1B)

Figure 2

High power image of peripancreatic tissue showing well preserved lymphomatous infiltrate, characterized by large cells with round nuclei and occasional prominent nucleoli

Figure 3

An intermediate magnification of pancreas tissue demonstrates diffuse infiltration of lymphoma with near effacement of normal pancreatic architecture

Figure 4

A kidney tissue section stained with antibody directed against CD20, highlighting the malignant cells, demonstrates disrupted renal tissue with lymphoma infiltrating between the tubules