Masafumi Suyama

Imaging of Small Pancreatic Ductal Adenocarcinoma

Symptoms and laboratory studies provide only limited assistance in the diagnosis of small pancreatic carcinomas. Ultrasound and computed tomography are best suited for screening small pancreatic carcinomas because of their ease and accuracy. When findings of ultrasound and computed tomography suggest small pancreatic carcinomas, MR cholangiopancreatography and endoscopic ultrasound should be indicated. Both techniques can show very small tumors. Follow-up of 77 patients with pancreatic carcinoma in whom the tumor was resected showed a 100% 5-year survival rate of patients with tumor limited to the duct epithelium. The majority of these tumors were <1 cm. These tumors are considered early pancreatic carcinoma.

Endoscopic ultrasound and intraductal ultrasound in the diagnosis of small pancreatic tumors

AbstractBackground: The purpose of this study was to assess the diagnostic value of endoscopic ultrasound (EUS) and intraductal ultrasound (IDUS) in the detection of small pancreatic tumors. Methods: EUS was performed in 166 patients with verified pancreatic disease. IDUS was performed in 46 patients. A microprobe was introduced into the main pancreatic duct through the papilla of Vater using the duodenoscope. Results: EUS was valuable in the detection of small pancreatic tumors. Ductal adenocarcinomas smaller than 1 cm were demonstrated as a hypoechoic mass with a central irregular hyperechoic area. EUS and IDUS were useful in the characterization of intraductal paillary tumors (ductectatic mucinous tumors). EUS demonstrated nodular excrescences, and IDUS depicted papillary proliferation of the duct epithelium, which are characteristic of carcinomas and adenomas but not of hyperplasia. Internal architecture of cystic neoplasms was clearly depicted by EUS, and differentiation of serous and mucinous tumors was readily achieved. A tumor as small as a 5-mm islet cell was demonstrated on EUS because islet cell tumors are very hypoechoic. Conclusion: EUS and IDUS are relatively noninvasive procedures and are useful in the detection of small tumors and differentiation of pancreatic diseases.

Japanese clinical practice guidelines for pancreaticobiliary maljunction

There have been no clinical guidelines for the management of pancreaticobiliary maljunction (PBM). The Japanese Study Group on Pancreaticobiliary Maljunction (JSPBM) has proposed to establish clinical practice guidelines on how to deal with PBM, with the support of the Japan Biliary Association (JBA). Because the body of evidence-based literature is relatively small, we decided to create guidelines based on the consensus of experts, using the medical literature for reference. A total of 46 clinical questions (CQs) were considered by the members of the editorial committee responsible for the guidelines. The CQs covered distinct aspects of PBM: (1) Concepts and Pathophysiology (10 CQs); (2) Diagnosis (10 CQs); (3) Pancreatobiliary complications (9 CQs); and (4) Treatments and prognosis (17 CQs). Statements and comments for each CQ were prepared by the guidelines committee members and collaborating partners. The CQs were completed after review by members of the editorial committee, meetings of this committee, public comments on the homepages of the JSPBM and the JBA, public hearings, and assessment and approval by the guidelines evaluation board. PBM includes cases where the bile duct is dilated (PBM with biliary dilatation) and those in which it is not (PBM without biliary dilatation). In these guidelines, PBM with biliary dilatation is defined as being identical to congenital biliary dilatation of Todani type I (except for type Ib) and type IV-A, both of which are accompanied by PBM in almost all cases. These guidelines are created to provide assistance in the clinical practice of PBM management; their contents focus on clinical utility, and they include general information on PBM to make this disease more widely recognized.

The detection and prognosis of small pancreatic carcinoma

SummaryDuring a period of 16 years, 203 proven pancreatic ductal adenocarcinomas were studied. Tumor size was measured on either the resected or the autopsy specimen. Four tumors were smaller than 1 cm, and 17 tumors were between 1.1 and 2 cm. ERCP has been found to be the most accurate in the diagnosis of small pancreatic carcinoma. Followup of 44 patients in whom the tumor was resected showed that survival depended on tumor size. In four patients with tumors smaller than 1 cm without parenchymal invasion, the postoperative 5-yr cumulative survival rate was 100%. Pancreatic carcinoma smaller than 1 cm limited to duct epithelium is considered as early cancer. Various diagnostic imaging modalities are now available to evaluate patients in whom pancreatic carcinoma is clinically suspected. These include ultrasonography (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and angiography. More recently magnetic resonance imaging (MRI), endoscopic ultrasound (EUS), and peroral pancreatic ductal biopsy also have been used. This report compares diagnostic modalities for pancreatic carcinoma in order to provide a data base for their rational use in the diagnosis of small resectable pancreatic carcinomas.

Stenting and interventional radiology for obstructive jaundice in patients with unresectable biliary tract carcinomas

Together with biliary drainage, which is an appropriate procedure for unresectable biliary cancer, biliary stent placement is used to improve symptoms associated with jaundice. Owing to investigations comparing percutaneous transhepatic biliary drainage (PTBD), surgical drainage, and endoscopic drainage, many types of stents are now available that can be placed endoscopically. The stents used are classified roughly as plastic stents and metal stents. Compared with plastic stents, metal stents are of large diameter, and have long-term patency (although they are expensive). For this reason, the use of metal stents is preferred for patients who are expected to survive for more than 6 months, whereas for patients who are likely to survive for less than 6 months, the use of plastic stents is not considered to be improper. Obstruction in a metal stent is caused by a tumor that grows within the stent through the mesh interstices. To overcome such problems, a covered metal stent was developed, and these stents are now used in patients with malignant distal biliary obstruction. However, this type of stent has been reported to have several shortcomings, such as being associated with the development of acute cholecystitis and stent migration. In spite of these shortcomings, evidence is expected to demonstrate its superiority over other types of stent.

Management of branch duct-type intraductal papillary mucinous tumor of the pancreas based on magnetic resonance imaging

Background: We assessed the usefulness of magnetic resonance imaging (MRI) in identifying nonmalignant intraductal papillary mucinous tumors (IPMTs) of the pancreas.Methods: Thirty-three patients with branch duct-type IPMT diagnosed by endoscopic retrograde cholangiopancreatography were prospectively examined with magnetic resonance cholangiopancreatography followed by dynamic gadolinium-enhanced MRI examinations, and patients with no findings suggestive of malignancy, including a solid mass, mural nodules, a main pancreatic duct wider than 5 mm in diameter, and stenosis of the main pancreatic duct, were prospectively followed up with sequential MRI examinations once or twice a year.Results: Twenty-six (79%) patients showed no findings suggestive of malignancy in the initial MRI examination. The diameter (mean ± standard error) of the main pancreatic duct was 3.9 ± 0.7 mm and that of the ectatic branch pancreatic duct was 36.0 ± 9.1 mm. Twenty-three patients were prospectively followed for more than 36 months and 22 of them showed no findings suggestive of malignancy during follow-up periods ranging from 39 to 77 months (mean = 55 months).Conclusion: MRI was useful to identify nonmalignant IPMTs of the branch duct type, and close follow-up observation with serial MRI examinations may be appropriate in the management of such patients.

Precancerous mucosal changes in the gallbladder of patients with occult pancreatobiliary reflux

BACKGROUND Pancreatobiliary reflux can occur even if the pancreaticobiliary junction is normal (occult pancreatobiliary reflux), and it may be associated with gallbladder carcinoma. The aim of the present study was to examine precancerous mucosal changes in the gallbladder from patients with occult pancreatobiliary reflux. METHODS The mucosa of the gallbladder from 13 patients who underwent cholecystectomy was examined histopathologically. These patients had an anatomically normal pancreatobiliary junction and a biliary amylase concentration greater than 10,000 IU/L. The gallbladder of patients without carcinoma was further examined by using immunohistochemical techniques to detect Ki-67, and the results were compared with those from control patients. RESULTS Of the 13 patients, 5 (38%) had gallbladder carcinoma and 8 (62%) did not. Of the 8 patients without carcinoma, 4 (50%) had dysplasia accompanied by hyperplasia, and 2 (25%) had hyperplasia alone of the gallbladder mucosa. The Ki-67 labeling index was significantly higher in hyperplastic and dysplastic mucosa than in control gallbladder mucosa (p < 0.0004). CONCLUSIONS Occult pancreatobiliary reflux could be associated with precancerous mucosal changes in the gallbladder, such as hyperplasia and dysplasia with increased cellular proliferation, and could be a possible risk factor for gallbladder carcinoma.

Early detection of extrahepatic bile-duct carcinomas in the nonicteric stage by using MRCP followed by EUS

BACKGROUND Most extrahepatic bile-duct carcinomas are usually diagnosed when they are already in an advanced stage, which is the main reason for the poor prognosis of this tumor. OBJECTIVE To examine the usefulness of MRCP followed by EUS in the early diagnosis of extrahepatic bile-duct carcinoma in the nonicteric stage. PATIENTS This study included patients who were nonicteric, who had abnormal serum concentrations of alkaline phosphatase and gamma glutamyl transpeptidase, and whose common hepatic duct was more than 8 mm in diameter on abdominal US because of unknown reasons. DESIGN A single-center, prospective study. SETTING An academic medical center. MAIN OUTCOME MEASUREMENTS The sensitivity and specificity of MRCP followed by EUS for the early diagnosis of extrahepatic bile duct carcinoma in the nonicteric stage. RESULTS A total of 142 patients who were nonicteric underwent prospective MRCP, and 26 of them underwent EUS. Ten patients (5 with stricture, 4 with filling defect, and 1 with no stricture or filling defect) had extrahepatic bile-duct carcinoma, including 5 patients with an incidentally diagnosed T1 stage tumor. The sensitivity and specificity of MRCP followed by EUS were 90% and 98%, respectively. LIMITATIONS A single center and small number of patients. CONCLUSIONS MRCP followed by EUS was highly sensitive and specific for the early diagnosis of extrahepatic bile-duct carcinoma in the nonicteric stage, including T1 stage tumors. Filling defects, as well as stenosis in the bile duct, are important MRCP findings of T1 stage carcinoma.

Primary hepatic marginal zone B-cell lymphoma with mantle cell lymphoma phenotype

We report a rare case of primary hepatic lymphoma, Stage II disease, in a 48-year-old male who had a solitary hepatic tumour measuring 4×4.5×3 cm. The tumour showed a nodular growth pattern and lymphoepithelial lesions with bile ducts. Some neoplastic nodules had a non-neoplastic atrophic germinal centre and/or a thin mantle cell layer. Morphologically, the neoplastic cells were centrocyte-like cells or intermediate lymphocytes. They expressed L26(CD20)+/LN-1(CDw75)±/LN-2(CD74)+/cyclin D1− and had a monotypic immunoglobulin of cytoplasmic IgM (к) on paraffin sections. The neoplastic cells or neoplastic nodules expressed surface IgM+/surface IgD±/Leu-1(CD5)+/DRC-1+/alkaline phosphatase+/B1(CD20)+/B4(CD19)− on fresh frozen sections. We therefore diagnosed this case as primary hepatic marginal zone B-cell lymphoma with mantle cell lymphoma phenotype. We confirm that it is difficult to differentiate extranodal marginal zone B-cell lymphoma (low grade B-cell lymphoma of mucosa-associated lymphoid tissue type; MALT lymphoma) and mantle cell lymphoma.

Pancreatic-duct–lavage cytology in candidates for surgical resection of branch-duct intraductal papillary mucinous neoplasm of the pancreas: should the International Consensus Guidelines be revised?

BACKGROUND The International Consensus Guidelines are helpful for the management of branch-duct intraductal papillary mucinous neoplasms (IPMNs), because they allow us to exclude malignancy. However, it is not possible to predict malignancy with certainty, and further preoperative differentiation between benign and malignant IPMNs is required to avoid the false-positive results. OBJECTIVE To examine the usefulness of pancreatic-duct-lavage cytology by using an originally designed double-lumen catheter for discriminating benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines. PATIENTS Pancreatic-duct-lavage cytology was investigated in 24 patients with branch-duct IPMNs who underwent surgical resection based on the International Consensus Guidelines, namely, they either had intramural nodules or the ectatic branch duct was >30 mm in diameter. DESIGN Single-center retrospective study. SETTING Academic medical center. MAIN OUTCOME MEASUREMENTS The sensitivity and specificity of pancreatic-duct-lavage cytology for discriminating benign from malignant IPMNs. RESULTS More than 30 mL of pancreatic-duct-lavage fluid was obtained from each patient, and there were no patients with noninformative results. The sensitivity, specificity, positive predictive value, and negative predictive value of the cytologic diagnosis were 78%, 93%, 88%, and 88%, respectively. LIMITATIONS Single-center and small number of patients. CONCLUSIONS Pancreatic-duct-lavage cytology can improve differentiation between benign and malignant IPMNs of the branch-duct type in candidates for surgical resection based on the International Consensus Guidelines.