Hilar cholangiocarcinomas grow slowly, and metastases occur late in the natural history. Surgical cure and long-term survival have been demonstrated, when resection margins are clear. Preoperative biliary drainage has been proposed as a way to improve liver function before surgery, and to reduce post-surgical complications. Percutaneous transhepatic biliary drainage (PTBD) with multiple drains was previously the preferred method for the preoperative relief of obstructive jaundice. However, the introduction of percutaneous transhepatic portal vein embolization (PTPE) and wider resection has changed preoperative drainage strategies. Drainage is currently performed only for liver lobes that will remain after resection, and for areas of segmental cholangitis. Endoscopic biliary drainage (EBD) is less invasive than PTBD. Among EBD techniques, endoscopic nasobiliary drainage (ENBD) is preferable to endoscopic biliary stenting (EBS), because secondary cholangitis (due to the retrograde flow of duodenal fluid into the biliary tree) does not occur. ENBD needs to be converted to PTBD in patients with segmental cholangitis, those with a prolonged need for drainage, or when the extent of longitudinal tumor extension is not sufficiently well characterized.

Objective The aim of the study was to develop a formula for predicting the probability of malignancy of mucinous cystic neoplasm (MCN) of the pancreas with ovarian-type stroma. Methods A total of 364 patients were enrolled. A total score was calculated as the sum of the approximate integers of the odds ratios of the predictive factors identified by multivariate analysis. The relationship between the total score and pathological results was assessed. Results A total of 321 patients had benign MCN and 43 had malignant MCN. Five possible predictive factors were analyzed: 56 years or older, high serum carcinoembryonic antigen level, high carbohydrate antigen 19-9 level, tumor size of 51 mm or greater, and the presence of mural nodules. The total score was significantly higher in patients with malignant MCN (median, 24; range, 0–37) compared with benign MCN (median, 5; range, 0–33; P < 0.001). Receiver operating characteristic curve analysis demonstrated that the area under the curve was 0.86, and the sensitivity and specificity of the total score for discriminating malignant MCNs were 72% and 83%, respectively, using a cut-off value of 22. Conclusions The current simple formula can predict the malignancy of MCN and may thus contribute to the adequate management of patients with MCN.

A 70-year-old woman was found to have 2 cystic lesions in the head of the pancreas on abdominal ultrasonography during a routine medical examination. Endoscopic ultrasonography (EUS) and magnetic resonance cholangiopancreatography showed multilocular cysts in the head of the pancreas without dilation of the main pancreatic duct. The patient was followed-up semiannually with imaging studies for suspected branch duct-type intraductal papillary mucinous neoplasm (IPMN). At 3 years after initial presentation, hypoechoic lesions were observed around each pancreatic cyst by EUS. Diffusion-weighted imaging showed high-intensity regions corresponding to these lesions. Therefore, a diagnosis of invasive carcinoma derived from IPMN could not be excluded, and subtotal stomach-preserving pancreaticoduodenectomy was performed. The macroscopic examination of the surgical specimen showed whitish solid masses in the head of the pancreas, with multilocular cysts within each mass. Microscopically, each solid mass consisted of inflammatory cells such as lymphocytes and plasma cells. Furthermore, immunochemical staining revealed immunoglobulin G4-positive cells, and many obliterating phlebitides were observed. The cysts consisted of mucus-producing epithelial cells and showed a papillary growth pattern. Based on these findings, we diagnosed multiple localized type 1 autoimmune pancreatitis occurring only in the vicinity of the branch duct-type IPMN.

UMIN000008109.

Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic tumor belonging to a newly recognized entity that is coined in the 2010 WHO classification. We present a case of ITPN-associated microinvasive adenocarcinoma that developed in an asymptomatic 78-year-old patient. The tumor demonstrated all the clinical, radiological, and pathological characteristics of ITPN, but it differs from other reported cases of ITPN in molecular analysis, which revealed a somatic mutation in BRAF (c.1799T>A; p.V600E) but no mutation in PIK3CA. Post-operative recurrence was discovered 34 months after tumor resection with negative margins and a 6-month course of adjuvant chemotherapy. To the best of our knowledge, this is the first case of ITPN with BRAF mutation. This case suggests that an activation of RAS-mitogen-activated protein kinase signaling pathway may play a role in development of some of ITPNs. A possible mechanism of tumor recurrence in ITPN is also discussed. Further case series with molecular study are awaited to delineate the clinicopathological and molecular characteristics of ITPN.