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.

Thymidylate synthase germline polymorphisms in rectal cancer patients treated with neoadjuvant chemoradiotherapy based on 5-fluorouracil.

PURPOSE: Chemoradiotherapy using 5-fluorouracil has shown to be effective treatment for rectal cancer. Thymidylate synthase (TS) is an important target enzyme for the fluoropyrimidines. However, the predictive role of TS levels in early stage rectal cancer is not yet well understood. We analyzed the value of TS gene polymorphisms as a predictive marker in patients with stage II and III rectal cancer treated with preoperative concomitant radiotherapy and fluoropyrimidine-based chemotherapy. METHODS AND MATERIALS: Between 1998 and 2007, blood samples were obtained from 51 patients with stage II/III rectal cancer. Forty patients were T2-3 (78%), 11 were T4 (22%), and 59% were N+. DNA was extracted from peripheral blood, and the genotypes were analyzed using PCR-restriction fragment length polymorphism and automated sequencing techniques. RESULTS: The *3/*3 thymidylate synthase genotype was associated with a higher response rate (pathological complete remission and microfoci residual tumor; 61 vs. 22% in *2/*2 and *2/*3; P = 0.013). In the multivariate analysis, the *3/*3 thymidylate synthase genotype was also an independent prognostic factor for better survival (P < 0.05). CONCLUSIONS: The thymidylate synthase genotype might help to identify patients with stage II/III rectal cancer who could benefit from pre- and postoperative fluorouracil-based chemotherapy.