Primary pancreatic lymphoma-diagnosed on computed tomography: A rare case report

Abstract

Primary pancreatic lymphoma is a rare disease. It comprises less than 0.5 % of pancreatic neoplasm and 0.1% of malignant lymphoma. It should be differentiated from pancreatic adenocarcinoma because management differs. At computed tomography, 2 types of morphology of primary pancreatic lymphoma have been described- a localized well-circumscribed tumoral form and another diffuse enlargement infiltrating or replacing most of the pancreatic gland. Here, we are presenting computed tomography (CT) imaging features of a case of primary pancreatic lymphoma in a 27 year old female who presented with a complaint of abdominal pain radiating to the back for 3 months and yellowish discoloration of sclera and skin for the last 15 days. In contrast-enhanced computed tomography an exophytic homogenously hypoenhancing mass arising from head and neck region of pancreas was seen. Involvement of common bile duct (CBD) and duodenum was there. The main pancreatic duct was not dilated. Common hepatic artery was encased by mass without arterial luminal narrowing or distortion. Diagnosis of primary pancreatic lymphoma was suggested on basis of imaging findings and further confirmed with fine-needle aspiration cytology.

Keywords: CT- Computed tomography, CBD- Commomn bile duct; Computed tomography; PET- Positron emission tomography, FNAC- Fine needle aspiration cytology; Pancreatic lymphoma; Primary pancreatic lymphoma; USG- Ultrasonography, HU- Hounsfield unit.

Fig. 1

Primary pancreatic lymphoma: (A) Non contrast, (B) pancreatic phase and (C) portal phase of CECT shows homogenously attenuating pancreatic head mass, hypoenhancing to pancreatic parenchyma in pancreatic and portal phase.

Fig. 2

Primary pancreatic lymphoma- Post contrast coronal and axial CT shows pancreatic mass obliterating common bile duct with obstructive changes in common hepatic duct and intrahepatic biliary radicles (thick black arrow). Gall bladder is overdistended (white arrow). Mass is infiltrating duodenum (thin black arrow) with obstructive changes in stomach. Main pancreatic duct is not dilated.

Fig. 3

Primary pancreatic lymphoma- Axial and coronal CECT - Pancreatic head mass encasing common hepatic artery (black arrow) and its branches (arrow heads) without luminal distortion and compressing portal vein (white arrow). A lobulated component or lymph nodal mass is seen close to pancreatic head mass (curved arrow).

Fig. 4

Primary pancreatic lymphoma: Axial and Coronal FDG PET/CT fusion image showing uptake in pancreatic mass.

Fig. 5

Primary pancreatic lymphoma: FDG PET scan 3D - Tracer uptake noted only in pancreatic region.