Evaluation of Imaging Findings of Pancreatobiliary and Intestinal Type Periampullary Carcinomas with 3.0T MRI.

RATIONALE AND OBJECTIVES: The aim of this study was to differentiate pancreatobiliary and intestinal type periampullary carcinomas using dynamic contrast MRI and MRCP (Magnetic Resonance Cholangiopancreatography) with diffusion-weighted imaging (DWI) MATERIALS AND METHODS: MRI and MRCP images of 70 patients with pathologically proven periampullary adenocarcinoma were included. MRCP image features, extra-ampullary features, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm² were evaluated by two radiologists independently. The interclass correlation coefficient (ICC) or Cohen's kappa statistic was used to evaluate the interobserver agreement. RESULTS: 51 patients were diagnosed with pancreatobiliary type carcinomas, and 19 with intestinal type. In the pancreatobiliary subtype, the distal wall of the common bile duct was usually irregular (p = 0.047). Although the progressive enhancement pattern was evident in the pancreatobiliary type, an oval filling defect in the distal common bile duct was found to be more common in the intestinal type (p<0.001). The pancreatic duct cut-off sign (p<0.001), gastroduodenal artery involvement (p <0,001), and lymphadenopathy (p<0.05) were mostly observed in pancreatobiliary carcinomas. The ADCmin, ADCmean, and ADCmax values of the pancreatobiliary type carcinomas were all lower compared to the intestinal type carcinomas (p <0.05). CONCLUSION: The oval filling defect seen in MRI and MRCP examinations suggests intestinal type, whereas the progressive contrasting pattern of the masses with irregular narrowing in the distal margin of the common bile duct, the pancreatic duct cut-off sign, gastroduodenal artery involvement, lymphadenopathy, and low ADC values indicate pancreatobiliary type carcinomas.

Extra-ampullary duodenal adenoma: a clinicopathological study.

AIMS: Extra-ampullary duodenal adenoma (EADA) is a rare condition with poorly described clinicopathological details. In this study, we aimed to characterize EADA clinicopathologically. METHODS AND RESULTS: We performed a retrospective review of 44 serial cases of EADA. Each EADA was categorized as either gastric-type (n = 5) or intestinal-type (n = 39). All gastric-type adenomas were located in the first portion of the duodenum and exhibited a pedunculated shape. Gastric-type adenomas were classified into two subtypes: pyloric gland and foveolar. The former consisted of mucin 6 (MUC6)-positive glands covered with MUC5AC-positive cells, whereas nearly all the latter consisted of MUC5AC-positive cells. When EADAs were categorized into high and low grades, approximately 40% (16 of 44) were high-grade. The high-grade adenomas were significantly larger than the low-grade adenomas (19.4 ± 8.6 mm versus 11.8 ± 5.1 mm, P = 0.021), and all adenomas greater than 20 mm in largest diameter were categorized as high-grade adenomas. Among 16 individuals who underwent total colonoscopy before or after duodenal mucosal resection, nine had a colorectal neoplasm, and all nine duodenal lesions were of the intestinal phenotype. CONCLUSIONS: We clarified the clinicopathological characteristics of gastric- and intestinal-type EADAs. EADAs greater than 20 mm at the largest diameter were consistently high-grade, and are thought to have the potential to progress to adenocarcinoma. These findings should be helpful for the clinical management of EADA.