Yoshitake Satomura

Clinical study of chronic pancreatitis with focal irregular narrowing of the main pancreatic duct and mass formation: comparison with chronic pancreatitis showing diffuse irregular narrowing of the main pancreatic duct.

Introduction Main pancreatic duct (MPD)-narrowed chronic pancreatitis (CP) may be an autoimmune abnormality. It also has been called autoimmune pancreatitis and sclerosing pancreatitis. It is unclear whether cases with focal pancreatographic changes are part of the same clinical entity as cases with diffuse MPD changes. Aim and Methodology We reviewed seven cases of chronic pancreatitis (CP) with focal narrowing of the main pancreatic duct (MPD), evidenced by endoscopic retrograde cholangiopancreatography (ERCP), and swelling of one or two segments of the pancreas, evidenced by ultrasonography (US) /computed tomography (CT), and indicated the clinicopathologic features of focal-type MPD-narrowed CP. Results The patient group comprised six men and one woman, and their age range was 28–75 years, with a mean of 63.7 years. Affected sites were in the head in two patients, the body in one patient, the tail in one patient, and the body and tail in three patients; ERP showed narrowing in six patients and obstruction in one. Stricture of the lower portion of the common bile duct (CBD) that caused obstructive jaundice was shown by ERC in two cases in which the pancreas head was affected. In all six patients, a dynamic study by CT or MRI homogeneously showed delayed enhancement of involved segments of the pancreas. Serum levels of pancreatic enzyme were elevated in five patients, but only one subject had pancreatitis-like epigastric pain. Serological evidence suggestive of autoimmune abnormality was detected in only three patients with hypergammaglobulinemia (≥2.0 g/dL) or positive titers of antinuclear antibody (ANA; ≥80). Histological assessment was available for five patients, who characteristically had dense lymphocytic or plasmocytic infiltration with severe fibrosis that caused luminal narrowing. The clinical, serologic, and histologic findings as described above were comparable to those for 12 CP patients with diffuse narrowing of the MPD, diagnosed during the same period. Surgical resection was performed in 5 patients, in 2 of whom a similar inflammatory process recurred in the remnant head of the pancreas, whereas pancreatitis no longer developed in the other 3 patients. One patient was initially treated with steroids, with clinical remission, although there was neither hypergammaglobulinemia nor positive ANA. Conclusion These results indicate that CP with focal narrowing of the MPD is part of the same clinical spectrum as CP with diffuse narrowing of the MPD, and whether the distribution is diffuse or focal seems to be related to the stage or the extent of the disease. It is therefore important to recognize the possible existence of this focal variant to avoid unnecessary surgery.

Identification of K‐ras Oncogene Mutations in the Pure Pancreatic Juice of Patients with Ductal Pancreatic Cancers

Pancreatic cancer is detected on the basis of morphological changes delineated by means of various image‐diagnostic methods. However, differentiation between chronic pancreatitis and pancreatic cancer, especially at the early stage, is not always simple when based upon the morphological changes alone. Therefore, we attempted to elucidate K‐ras mutations in the sediment of pure pancreatic juice (PPJ) containing exfoliated ductal pancreatic cancer cells. PPJ was collected endoscopically from 20 patients with pancreatic cancer (PC) and 18 patients with chronic pancreatitis (CP). Polymerase chain reaction and allele specific oligonucleotide dot blot hybridization for K‐ras mutations were performed with the DNA extracted from these samples. A K‐ras mutation at codon 12 was identified in the PPJ of 11/20 (55%) of the patients with PC. On the other hand, the same mutation was not identified in the PPJ of any patient with CP. Moreover, K‐ras mutations at codons 13 and 61 were not recognized in the PPJ of any patient with either PC or CP. These findings suggested that the presence of a K‐ras mutation at codon 12 in PPJ would be useful in confirming the diagnosis of PC.

Detection of K-ras point mutations at codon 12 in pure pancreatic juice for the diagnosis of pancreatic cancer by PCR-RFLP analysis

The present study was undertaken to detect K-ras point mutations at codon 12 in pure pancreatic juice (PPJ) for the diagnosis of pancreatic cancer (PC) using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. PPJ was collected through a cannula under a duodenal fiberscope from 26 patients with PC and 32 patients with chronic pancreatitis (CP). DNA was extracted from PPJ and was used as the template for PCR. Analysis of PPJ by PCR-RFLP with Bst NI revealed that the incidence of K-ras point mutations at codon 12 was 81% (21/26) in patients with PC and 6% (2/32) in those with CP. With reference to the location of PC, the incidence of K-ras mutations was 79% (11/14) in the head, 86% (6/7) in the body, and 80% (4/5) in the tail of the pancreas. The incidence of K-ras mutants was 50% (1/2) in tumor size 1 (TS1; ≤2.0 cm in size), 71% (5/7) in TS2 (2.1 to ≤4.0 cm), 89% (8/9) in TS3 (4.1 to ≤6.0 cm), and 88% (7/8) in TS4 (>6.1 cm). These results suggested that analysis of K-ras point mutations at codon 12 in PPJ using the PCR-RFLP method is a promising new genetic test for the diagnosis of PC.

Clinical management of intraductal papillary mucinous tumors of the pancreas based on imaging findings.

The aim of this study was to assess the imaging findings of pathologically proven intraductal papillary-mucinous tumors of the pancreas and the natural history of follow-up cases, and to optimize the therapeutic management of patients with these tumors according to their imaging findings. All nine patients with main duct type tumors were histologically diagnosed as having adenocarcinoma or adenoma, with no hyperplastic lesion. The images failed to discriminate between the two histologic types. In 26 patients with branch duct type tumors, all but one with intraductal mural nodules or tumors of ≧30 mm had adenocarcinoma or adenoma, regardless of the caliber of the main duct. Of the nine patients with tumors < 30 mm and no mural nodules, three had adenoma, and six had hyperplasia. All of four patients had hyperplasia, with the additional caliber of the main duct being < 6 mm. In a series of 23 cases in which the patient was followed-up, no apparent progression was found in 17 patients who had no mural nodules and tumors of < 30 mm. Given these results, patients with main duct type tumors, and those with branch duct type tumors showing mural nodules or a tumor diameter of ≧30 mm, are at high risk of developing neoplasms, including adenocarcinoma, for which surgical resection should be considered, whereas those patients with tumors < 30 mm and no mural nodules can be followed.

Biliary papillomatosis with the point mutation of K-ras gene arising in congenital choledochal cyst.

Biliary papillomatosis is a rare entity. A case of biliary papillomatosis associated with congenital choledochal cyst and intrahepatic gallstones is reported here. Percutaneous transhepatic cholangioscopy revealed multiple papillary lesions of the right intrahepatic duct and the common bile duct. Microscopically, the papillary mucosal lesion showed papillary proliferations of bile duct epithelial cells with mild atypia. Furthermore, a point mutation at codon 12 of the K-ras oncogene was found in the papillary lesion. To the best of our knowledge, this is the first case of biliary papillomatosis arising in congenital choledochal cyst. Although the pathogenesis of biliary papillomatosis in our case was unclear, biliary irritation associated with choledochal cyst may be related to biliary papillomatosis with point mutation at codon 12 of K-ras gene.

Expression of various sialylated carbohydrate antigens in malignant and nonmalignant pancreatic tissues.

The expression of six sialylated carbohydrate antigens (CA19–9, CA-SO, SLEX, SLX, DU-PAN-2, ST-439) was examined in malignant and nonmalignant pancreatic tissues using an immunohistochemical method to elucidate the characteristics of these carbohydrate antigens as tumor markers. All carbohydrate antigens except for sialyl SSEA-I (SLX, 52.4%) were expressed in more than 80% of the pancreatic cancer. CA19–9 and CA-50, belonging to type I blood group antigens, and DU-PAN-2 and ST-439 were localized predominantly in the cytoplasm of cancer cells, while sialyl Lex (SLEX) and SLX, belonging to type II blood group antigens, were stained mainly on the apical membranes of malignant glands. Although type I antigens were expressed in most nonmalignant pancreatic tissues, the type II antigens and ST-439 were absent in almost all of the normal tissues and faintly expressed in few chronic pancreatitis tissues, suggesting the high tumor specificity of these antigens. Each antigen was expressed on the apical surface of ducts in normal pancreas. However, in about 30% of chronic pancreatitis cases, type I antigens and DU-PAN-2 were observed in the cytoplasm of ductal cells. All patients showing stromal stain, possibly caused by loss of antigen polar expression and shedding into the surrounding stroma adjacent to malignant glands, revealed high levels of serum antigen. This finding suggests that the stromal appearance of antigens is a significant factor in the elevation of serum antigen levels.

Serum Levels of Pancreatitis-Associated Protein in Digestive Diseases with Special Reference to Gastrointestinal Cancers

The serum levels of pancreatitis-associatedprotein (PAP) were measured in 196 patients withdigestive diseases and 15 healthy subjects by anenzyme-linked immunosorbent assay. The serum PAP levelswere significantly elevated in the patients withgastric, colorectal, biliary tract, hepatocellular, orpancreatic cancers compared with the healthy subjects.After curative resection of the tumor, serum PAP levels were significantly decreased. The serumPAP levels were not related to clinicopathologicalfactors except for the tumor size of pancreatic cancer.There were some cases of PAP-positive andcarcinoembryonic antigen (CEA) or carbohydrate antigen (CA)19-9-negative gastric and colorectal cancers. The serumPAP levels were also significantly elevated in thepatients with acute pancreatitis compared with those in not only the healthy subjects but also thepatients with chronic pancreatitis. The peak PAP levelswere significantly correlated with the severity of acutepancreatitis and reflected the clinical healing of the disease. The peak of serum PAP wassignificantly delayed compared with those of otherpancreatic enzymes. These results suggest that theincrease of serum PAP levels in patients withgastrointestinal cancers reflects an ectopic expression of PAPin cancer cells and that increased serum levels of PAPin acute pancreatitis are correlated with the diseaseseverity and are prolonged than those of other pancreatic markers.

Detection of K-ras Point Mutations at Codon 12 in Pancreatic Juice for the Diagnosis of Pancreatic Cancer by Hybridization Protection Assay: A Simple Method for the Determination of the Types of Point Mutations

The present study was undertaken to detect K‐ras oncogene point mutations at codon 12 in pure pancreatic juice (PPJ) by the hybridization protection assay (HPA) method for the diagnosis of pancreatic cancer (PC). This assay can be carried out within 30 min and can determine not only the presence of a mutation, but also the mutational type of K‐ras at codon 12. The minimal ratio of mutant DNA detectable by the HPA was 5–10% of the total DNA. PPJ was collected through a cannula under duodenal fiberscope control from 20 patients with PC and 20 patients with chronic pancreatitis (CP). Analysis of PPJ by the HPA revealed that the incidence of K‐ras point mutations at codon 12 was 55% (11/20) in patients with PC and 0% (0/20) in those with CP. Mutational types of K‐ras at codon 12 in PC were aspartic acid (Asp) in nine cases, both Asp and cysteine in one case, and arginine in one case. Analysis of K‐ras point mutations at codon 12 in PPJ using the HPA method seems promising as a new genetic test for the diagnosis of PC, because the HPA method is simple, and can easily determine the mutational type.

Measurement of serum PSP/reg-protein concentration in various diseases with a newly developed enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay, based on two monoclonal antibodies (Hreg1-1 and Hreg101-1) specific for pancreatic stone protein (PSP)/reg-protein, was developed to determine the concentration of this protein in serum from individuals with various diseases. The serum concentration of PSP/reg-protein was significantly higher in patients with various pancreatic diseases than in normal controls, and was also significantly higher in patients with acute pancreatitis or chronic relapsing pancreatitis than in patients with chronic pancreatitis. Furthermore, the serum PSP/reg-protein concentration was also significantly increased in liver cirrhosis, choledocholithiasis, and various cancers of the digestive system, and was extremely high in all patients tested with chronic renal failure. A significant correlation was apparent between the serum concentration of PSP/reg-protein and elastase-I in 68 patients with chronic pancreatitis or pancreatic cancer. Whereas only 7 of these patients showed a normal serum PSP/reg-protein concentration and a significantly increased elastase-I concentration, 15 of these patients showed a significantly increased serum PSP/reg-protein coecentration and a normal serum elastase-1 concentration. These results indicate that the serum PSP/reg-protein concentration may reflect pancreatic damage, especially in acute pancreatitis, and may be as sensitive a marker for such damage as elastase-I, although false positivity was apparent in renal failure and in some patients with hepatic dysfunction or digestive system malignancies.

The immunohistochemical evaluation of PSP/reg-protein in normal and diseased human pancreatic tissues

SummaryIn order to elucidate the characteristics ofreg-protein, which is identical to pancreatic stone protein (PSP/reg-protein), and the relationship between the generation and evolution of chronic pancreatitis and the expression of PSP/reg-protein in the pancreas, we investigated the expression of PSP/reg-protein in normal and diseased human pancreatic tissues by immunohistochemistry. The PSP/reg-protein was expressed in all cases with normal pancreas or chronic pancreatitis, and in 70.6% of cases with pancreatic cancer. This protein was present in the cytoplasm of acinar cells and, in some cases, in the intraluminal contents of ductules in nonmalignant tissues. From the view of distribution and cellular localization, PSP/reg-protein was expressed more broadly and densely in chronic pancreatitis with mild to moderate injury than in the normal pancreas. However, the protein was less expressed in severely damaged chronic pancreatitis tissue, such as calcifying pancreatitis, than in the normal pancreas. These findings suggest that mild to moderate injury to pancreatic tissue may stimulate the synthesis of PSP/reg-protein, whereas more severe injury tends to depress it.