Pancreatoduodenal junction: review of anatomy and pathologic conditions.

INTRODUCTION: The pancreatoduodenal junction is a small anatomic area where pathologic processes involving the distal bile duct, duodenum, pancreatic head, ampulla de Vater, and retroperitoneum converge. Differential diagnosis includes a spectrum of entities that ranges from anatomical variants to malignancies.

PURPOSE: The aim of this paper was to review the anatomy and different pathologic conditions, whether tumoral, inflammatory, or congenital in origin, in this specific area that involves the pancreatic head, duodenum, duodenal ampulla, distal pancreatobiliary tract junction, and retroperitoneum.

METHODS: Computed tomography (CT) and magnetic resonance (MR) help us to identify specific radiologic signs that allow to divide the pancreatic-duodenal junction abnormalities into three cathegories: (1) normal variants and congenital anomalies (pancreas divisum, santorinicele, annular pancreas,duodenal duplication cyst, choledocal cyst,...); (2) acquired non-tumoral: traumatic, iatrogenic, inflammatory (duodenal hematoma, duodenal iatrogenic perforation, groove pancreatitis, gastroduodenal artery pseudoaneurysm,...); (3) tumoral (pancreatic head adenocarcinoma, periampullary tumors, neuroendocrine pancreatic tumors, duodenal adenocarcinoma,...). The images illustrate morphologic aspects of these entities.

RESULTS AND CONCLUSIONS: CT and MR are the most appropiate imaging modalities to evaluate pancreatoduodenal junction. Knowing the imaging features is crucial to reach the right diagnosis and treatment of the different entities that involve this anatomic area.