Expression of oncogene products, anti-oncogene products and oncofetal antigens in intraductal papillary-mucinous neoplasm of the pancreas

A few previous studies have demonstrated the expression or mutations of oncogenes and anti-oncogenes as well as that of oncofetal antigens in intraductal papillary-mucinous neoplasm of the pancreas. In this study, we have investigated the immunohistochemical expression of oncogene (ras and c-erbB-2) and anti-oncogene (p53 and retinoblastoma [Rb]) products and oncofetal antigens (CEA, CA19-9 and DUPAN-2) in nine such tumours of the pancreas. In normal pancreas (5 cases), the Rb gene product and CA19-9 were expressed in all cases, while ras and c-erbB-2 gene products, p53 protein, CEA and DUPAN-2 were not expressed. In intraductal papillary-mucinous tumours (n = 9), ras, c-erbB-2, p53 and Rb gene products were present in 4/9 (44%), 7/9 (78%), 0.9 (0%) and 6/9 (67%) cases, respectively. CEA, CA19-9 and DUPAN-2 were expressed in 8/9 (89%), 9/9 (100%) and 2/9 (22%) cases respectively. In invasive ductal adenocarcinoma of the pancrease (7 cases), ras, c-erbB-2, p53 and Rb gene products were expressed in 3/7 (43%), 6/7 (86%), 2/7 (29%) and 3/ & (43%) cases respectively. CEA, CA19-9 and DUPAN-2 were expressed in 7/7 (100%), 7/7 (100%) and 6/7 (86%) cases, respectively. The extent and intensity of the expression of these antigens was greater in invasive ductal adenocarcinomas. These data suggest that activation of ras and c-erbB-2 oncogenes and inactivation of Rb anti-oncogene may contribute to the development and progression of intraductal papillary-mucinous tumours of the pancreas and that there is neo-expression of CEA and DUPAN-2 during the development and progression of these tumours.     

EXPRESSION OF MUC APOMUCINS IN NORMAL PANCREAS AND PANCREATIC TUMOURS

The epithelial expression of apomucins MUC1, MUC2, MUC3, and MUC5/6 was examined in normal pancreas and in pancreatic lesions, using immunohistochemical methods. In normal pancreas ( n =5), MUC1 apomucin was expressed in ducts and some acini, but there was no expression of MUC2, MUC3, or MUC5/6. In chronic pancreatitis ( n =5), MUC1 apomucin was expressed, but expression of the other apomucins was not noted. However, mucous hyperplastic foci of pancreatic ducts expressed MUC5/6 apomucin in 2/5 cases (40 per cent). In intraductal papillary-mucinous neoplasm (IPMN) of the pancreas ( n =9), MUC1, MUC2, MUC3, and MUC5/6 apomucins were expressed in 8/9 (89 per cent), 0/9 (0 per cent), 4/9 (44 per cent), and 9/9 (100 per cent) cases, respectively. In pancreatic mucinous cystadenoma ( n =8), MUC1, MUC2, MUC3, and MUC5/6 apomucins were expressed in 7/8 (88 per cent), 0/8 (0 per cent), (25 per cent), and 3/8 (38 per cent) cases, respectively. In invasive ductal adenocarcinoma of the pancreas ( n =25), expression of MUC1, MUC2, MUC3, and MUC5/6 apomucins was found in 25/25 (100 per cent), 1/25 (4 per cent), 20/25 (80 per cent), and 24/25 (96 per cent) cases, respectively. Atypical mucous duct hyperplasia near cancer cells consistently expressed MUC1 apomucin and occasionally expressed MUC3 and MUC5/6. In positive cases, MUC1 apomucin expression was noted in the cell membrane facing the ductal or neoplastic lumina, while expression of MUC2, MUC3, and MUC5/6 apomucins was found in the cytoplasm. These results suggest that MUC3 and MUC5/6 apomucins newly emerge during the neoplastic transformation of pancreatic mucinous cystadenoma and IPMN and during pancreatic ductal carcinogenesis, while MUC1 apomucin remains positive and MUC2 apomucin remains almost negative during neoplastic transformation.     

''Metaplastic lesions'' in intrahepatic bile ducts in hepatolithiasis: A histochemical and immunohistochemical study

Pathology of the intrahepatic bile ducts bearing calculi was examined with an emphasis on metaplasia in 22 cases of hepatolithiasis and in seven cases of normal livers. Normal livers contained few glandular elements within the bile duct walls and no metaplastic lesions or endocrine cells. In hepatolithiasis, a number of mucous glands resembling pyloric glands (pseudopyloric gland metaplasia) were seen within duct walls in all cases. The epithelial cells of the glands were positive for class III mucin with paradoxical concanavalin A staining which is known to be specific for pyloric glands. These cells were also positive for neutral, sialo- and sulfomucin to a variable extent. Intestinal metaplasia, including goblet cell and Paneth cell metaplasia, was found within duct walls and in covering epithelia in five (23%) cases. Endocrine cells, including argyrophil, argentaffin and gut hormone-containing cells were present in these metaplastic lesions in 13 (59%) cases. The occurrence of endocrine cells was closely associated with intestinal metaplasia, although there were a few endocrine cells in metaplastic pseudopyloric glands. These findings suggest that metaplastic lesions similar to the well-known metaplastic lesions in the gallbladder occur in the intrahepatic bile duct walls in hepatolithiasis. The appearance of metaplastic lesions and endocrine cells may be causally related to chronic inflammatory processes associated with hepatolithiasis.     

‘Atypical adenomatous hyperplasia’ in liver cirrhosis: low-grade hepatocellular carcinoma or borderline lesion?

Adenomatous hyperplasia, defined as a sizable parenchymal nodule in cirrhosis, was examined morphologically. Ninety-seven nodules of adenomatous hyperplasia were obtained from 47 cirrhotic livers and were divided into 'ordinary' (44 nodules) and 'atypical' (53 nodules) types. The former consisted of hepatocytes similar to those of the surrounding liver, and showed regularly distributed portal tracts. The latter type was composed of hepatocytes showing nuclear atypia, relative to the surrounding liver, and showed irregular or sparse portal tracts. Atypical nodules were histologically heterogeneous, possessing areas of normo-trabecular, compact, pseudoglandular and/or scirrhous patterns. Several cytological changes, such as clear cell change, small or large cell change and fatty change, were intermingled variably within a given nodule. Atypical nodules showed expansive and/or replacing growth into the surrounding liver. Atypical hepatocytes also infiltrated into the fibrous septa and portal tracts. Foci of overt hepatocellular carcinoma were found in 11 of the 53 atypical nodules. These findings suggest that ordinary adenomatous hyperplasia may be a large-sized regenerative nodule, while atypical adenomatous hyperplasia may be a hepatocellular neoplasm, a peculiar form of low-grade hepatocellular carcinoma or borderline lesion, in which overt hepatocellular carcinoma is likely to evolve through multiple steps.     

Expression of alpha-amylase isoenzymes and trypsin by the proliferating epithelium of large intrahepatic bile ducts and intrahepatic peribiliary glands in hepatolithiasis

The expression of alpha-amylase isoenzymes (pancreatic and salivary) and trypsin by the epithelium of large intrahepatic bile ducts and peribiliary glands was examined immunohistochemically in hepatolithiasis ( n = 22), extrahepatic biliary obstruction ( n = 20) and normal liver ( n = 22). Hepatolithiasis was associated with marked proliferation of bile duct cells and peribiliary glands. Expression of pancreatic and salivary amylase was observed in the proliferating bile duct cells and peribiliary glands of all livers, and trypsin was found in 68% of the livers. In extrahepatic biliary obstruction, proliferation of the biliary epithelium was less marked, but expression of amylase isoenzymes was observed in all livers and trypsin was found in 50%. All normal livers showed expression of amylase isoenzymes in large intrahepatic bile ducts, septal bile ducts and peribiliary glands, and trypsin was found in 73%. The density of enzyme-containing acini was highest in hepatolithiasis, intermediate in extrahepatic biliary obstruction and lowest in normal liver. These results show that the proliferating biliary epithelium in hepatolithiasis contains amylase isoenzymes and trypsin and that biliary epithelium retains the ability to produce these enzymes after proliferation, suggesting that a large amount of amylase isoenzymes and trypsin may be secreted into the bile ducts in hepatolithiasis. These enzymes may play an important role in the pathophysiology of hepatolithiasis.     

Histological features and interphase nucleolar organizer regions in hyperplastic, dysplastic and neoplastic epithelium of intrahepatic bile ducts in hepatolithiasis

Neoplastic transformation occurs in the intrahepatic biliary tree in hepatolithiasis. The present study aimed to clarify the neoplastic processes by correlating the histological features of the bile duct lesions with counts of interphase argyrophilic nucleolar organizer regions (AgNORs), which reflect cell proliferative activity. We studied 55 cases of hepatolithiasis and 25 normal autopsy livers. The biliary epithelial lesions in hepatolithiasis were divisible into hyperplasia, dysplasia and neoplasia. These lesions were found in bile ducts containing calculi. All cases of hepatolithiasis showed a varied degree of hyperplasia. Additionally, eight cases showed dysplasia, five non-invasive intraductal adenocarcinoma and 10 invasive adenocarcinoma. Cases of non-invasive and invasive carcinoma frequently harboured areas of dysplasia, and areas of dysplasia and non-invasive carcinoma, respectively. The mean and standard deviation of the number of interphase AgNORs in the normal and abnormal biliary epithelium showed a step-wise increase in the following order: normal (1.32 +/- 0.36), hyperplasia (1.52 +/- 0.37), dysplasia (2.28 +/- 0.56), non-invasive carcinoma (3.23 +/- 1.00), and invasive carcinoma (3.72 +/- 0.77). These histological and cell kinetic observations suggest that, in hepatolithiasis, carcinogenesis in bile duct epithelial cells progresses in a multi-step manner, through hyperplasia, dysplasia, non-invasive adenocarcinoma and invasive adenocarcinoma.     

Intrahepatic peribiliary glands of humans. II. Pathological spectrum

Abstract The pathological spectrum of intrahepatic peribiliary glands is reviewed here. Several categories of histopathological changes such as necro-inflammation, cystic dilatation, hyperplasia and neoplasia have been identified in this glandular system. Necro-inflammation is associated with biliary tract diseases and chronic advanced liver diseases and may also appear in the livers of subjects with extrahepatic diseases such as sepsis. Cystic changes of microscopic sizes are not uncommon in autopsy livers of chronic advanced liver diseases, portal hypertensive diseases and also polycystic liver of adult type. Grossly recognizable cysts are, however, infrequent and occasionally cause compression of the adjoining bile ducts. Hyperplasia of these glands, which occurs consistently in hepatolithiasis and more variably in other conditions (e.g. biliary tract infection and submassive hepatic necrosis), may be associated with hypersecretion of seromucinous substances. Hyperplasia of peribiliary glands may then lead to mucin-related biliary diseases. In addition, these glands, particularly the hyperplastic ones, could be a precursor of cholangiocarcinoma. The pathological spectrum of the intrahepatic peribiliary glands is being expanded, although a clinical pathological correlation remains uncharted. Furthermore, age-related variations and non-specific reactive changes of these glands remain unexplored.     

Diffuse biliary tract involvement mimicking primary sclerosing cholangitis in an experimental model of chronic graft-versus-host disease in mice

Experimental graft-versushost disease (GVHD) across minor histocompatibility antigens was developed by injecting spleen and bone marrow cells (9:1) of congenic B10.D2 mice into sublethally Irradiated BALB/c mice, and the histologic features of the Iiver were studied for up to 14 months after transplantation. Both intrahepatic and extrahepatic bile ducts were severely involved in the GVHD process and showed features of non-suppurative cholangitis. Inflammatory cells, mainly lymphocytes, abutted the bile ducts and Infiltrated Into the duct eplthellal layer together with a variety of degenerative changes in the epithelial cells. The peak Inflammatory activity occurred about 2–3 weeks after transplantation. Thereafter, the inflammatory cell Infiltration around the bile ducts and In the bile duct epithelial layer gradually became reduced in severity, although the infiltration persisted during the entire 14 month observation period. Periductal and duct wall fibroplasia began about 1 week after transplantation and gradually progressed. After 2–3 months post-transplantation, distinct ductal and periductal fibrosis of both intrahepatic and extrahepatic blle ducts was observed. This histologic feature resembled that of primary sclerosing cholangitis (PSC). These results suggest that PSC lesions might develop as a result of chronic cellular Immunologic mechanisms In GVHD across minor histocompatibility barriers.     

Histopathology of portal tracts in livers after transcatheter arterial chemo-embolization therapy for hepatocellular carcinoma

Abstract To study the influence of transcatheter arterial embolization therapy (TAE) on the portal tracts, 32 cases of hepatocellular carcinoma (HCC) with a history of TAE were examined. Portal tract elements are said to be mainly supplied by hepatic arterial blood, as is HCC. The following changes were found: peribile duct fibrosis; biliary epithelial injuries; bile duct necrosis; fibrous thickening of the intima and adventitia of arteries; thrombosis or stenosis of portal vein branches; and fibrosis of portal tract itself. We failed to correlate these histopathologic changes with the frequency of TAE or the interval between TAE therapy and surgery or autopsy. Semi-quantitative assessment disclosed that vessels of the peribiliary vascular plexus (PVP) which are known to be derived from hepatic arterial branches, were considerably decreased. There was little correlation between the degree of reduction of PVP and the observed histopathologic changes of portal tracts. It is suggested that TAE causes adverse effects on the elements of portal tracts and a reduction in the PVP in the vicinity of HCC, but the relationship between them is unclear.     

Obstructive jaundice caused by the deposition of amyloid-like substances in the extrahepatic and large intrahepatic bile ducts in a patient with multiple myeloma

Obstructive jaundice has rarely been reported in liver amyloidosis. We report here an autopsy of a 55-year-old woman with multiple myeloma and obstructive jaundice due to the deposition of amyloid-like substances in the walls and lumina of the extrahepatic bile duct and intrahepatic large bile ducts, resulting in obstruction and narrowing of the bile ducts. The amyloid-like deposits were negative with Congo red stain, and were negative immunohistochemically for IgG, IgA, IgM, kappa chain, beta-2-microglobulin, and amyloid A and P components. However, they were positive for lambda chain, and ultrastructurally composed of non-branching filaments with a diameter of 7–10 nm. This is the first case of obstructive jaundice due to histologically confirmed amyloid-like deposits in the biliary system.