Shinji Masuda

Igg4-related Sclerosing Cholangitis With and Without Hepatic Inflammatory Pseudotumor, and Sclerosing Pancreatitis-associated Sclerosing Cholangitis: Do They Belong to a Spectrum of Sclerosing Pancreatitis?

Sclerosing cholangitis (SC) is a heterogeneous disease entity. Different etiologies such as choledocholithiasis, biliary tumor, or pericholangitis can manifest as SC. Hepatic inflammatory pseudotumor (IP) is rarely associated with SC (sclerosing cholangitis associated with hepatic inflammatory pseudotumor; SC-hepatic IP), but sclerosing pancreatitis (SP) is not infrequently associated with bile duct lesions (sclerosing pancreatitis-associated sclerosing cholangitis; SP-SC). In this study, we compared the histologic changes of hepatic hilar and extrahepatic bile duct lesions of SC (7 cases), SC-hepatic IP (5 cases), SP-SC (5 cases), and typical primary sclerosing cholangitis (PSC) (5 cases). Histologically, all SP-SC cases showed extensive and dense fibrosis with marked lymphoplasmacytic infiltration, many eosinophils, and obliterative phlebitis. Four cases of SC showed bile duct lesions similar to those of SP-SC, whereas other three cases of SC showed milder lymphoplasmacytic infiltration, scant eosinophilic cell infiltration, and no obliterative phlebitis. All SC-hepatic IP cases showed bile duct lesions identical to those of SP-SC. Immunohistochemically, many IgG4-positive plasma cells were found in the bile duct lesions of all SP-SC cases, 4 SC cases with marked lymphoplasmacytic infiltration, and all SC-hepatic IP cases. By contrast, IgG4-positive plasma cells were scarce or hardly found in the remaining 3 SC cases and all PSC cases. In conclusion, 4 SC cases and all SC-hepatic IP cases showed bile duct lesions identical to those of SP-SC, suggesting that these three conditions may be a single disease entity. Their pathogenesis may be similar or closely related to that of SP, and in that respect they may represent an IgG4-related biliary disease. They may respond to steroid therapy as SP does.

Abundant IgG4-positive plasma cell infiltration characterizes chronic sclerosing sialadenitis (Kuttner's tumor)

Chronic sclerosing sialadenitis (CSS) is a cryptogenic tumor-like condition of the salivary gland(s). While immune-mediated processes are suspected in its pathogenesis, and CSS is occasionally reported to be associated with sclerosing pancreatitis, an IgG4-related disease, the exact immunopathologic processes of CSS remain speculative. In this study, we examined the clinicopathologic findings of CSS (12 cases) in comparison with sialolithiasis (8 cases) and Sjögrens syndrome (13 cases), and tried to clarify whether CSS is an IgG4-related disease or not. Submandibular gland(s) were affected in all cases of CSS. CSS cases could be divided into two types: 5 cases were associated with sclerosing lesions in extrasalivary glandular tissue (systemic type), while only salivary gland(s) were affected in the remaining 7 cases (localized type). In the former type, which showed male predominance, bilateral salivary glands were frequently affected, and eosinophilia and elevations of γ-globulin and IgG in serum were frequently found. Histologically, all cases of CSS showed marked lymphoplasmacytic infiltration admixed with fibrosis and the destruction of glandular lobules. Obliterative phlebitis was found in the affected salivary glands in all cases of CSS. Immunohistochemically, the proportion of IgG4/IgG-positive plasma cells was more than 45% in CSS, while it was less than 5% in controls. The resemblance of the clinicopathologic features of CSS with those of sclerosing pancreatitis suggests the participation of a similar immunopathologic process with IgG4 disturbance in CSS. The abundance of IgG4-positive plasma cells in the lesions would be useful for distinguishing CSS from other forms of sialadenitis.

Biliary Papillary Tumors Share Pathological Features With Intraductal Papillary Mucinous Neoplasm of the Pancreas

Recently, attention has been drawn to papillary neoplasm of the pancreatobiliary systems. In the pancreas, the disease entity of intraductal papillary mucinous neoplasm (IPMN‐P) is widely recognized. In contrast, the pathological characteristics of biliary papillary tumors, such as biliary papilloma(tosis) and papillary cholangiocarcinoma, have not yet been well documented. In this study, we compared the pathological features and post‐operative prognosis among biliary papillary tumors (10 cases of biliary papilloma(tosis) and 22 cases of papillary cholangiocarcinoma), conventional non‐papillary cholangiocarcinoma (15 cases), and IPMN‐P (31 cases). Macroscopically, all biliary papillary tumors were characterized by the prominent intraductal papillary proliferation, and macroscopic mucin‐hypersecretion was seen in 9 of 32 cases (28%). Histologically, biliary papillary tumors consisted of three types of tumor cells (pancreaticobiliary, intestinal and gastric types), whereas only the pancreaticobiliary type was observed in non‐papillary cholangiocarcinoma. Immunohistochemically, biliary papillary tumors were characterized by the common expression of MUC2, CDX2 and cytokeratin 20. In addition, biliary papillary tumors could be associated with two types of invasive lesions: tubular adenocarcinoma (9 cases) and mucinous carcinoma (5 cases). Patients with tubular adenocarcinoma had a poor prognosis compared to non‐invasive papillary tumor or papillary tumor with mucinous carcinoma. These pathological characteristics and the survival status of biliary papillary tumors were different from those of non‐papillary cholangiocarcinoma, and rather closely resembled those of IPMN‐P. In conclusion, biliary papillary tumors may be the biliary counterpart (intraductal papillary neoplasm of the bile duct) of IPMN‐P. (HEPATOLOGY 2006;44:1333–1343.)

Pathological classification of hepatic inflammatory pseudotumor with respect to IgG4-related disease

Recently, much attention has focused on IgG4-related disease, which is characterized by abundant IgG4-positive plasma cell infiltration and high serum IgG4 levels. IgG4-related disease sometimes manifests as tumorous lesions, and its relationship to inflammatory pseudotumor has been suggested. In this study, we examined clinicopathological features of a total of 16 cases of hepatic inflammatory pseudotumor (11 men and 5 women with an average age of 67 years) with respect to IgG4-related disease. The tumors could be pathologically classified into two types: fibrohistiocytic (10 cases) and lymphoplasmacytic (6 cases). Fibrohistiocytic inflammatory pseudotumors were characterized by xanthogranulomatous inflammation, multinucleated giant cells, and neutrophilic infiltration, and mostly occurred in the peripheral hepatic parenchyma as mass-forming lesions. In contrast, lymphoplasmacytic inflammatory pseudotumors showed diffuse lymphoplasmacytic infiltration and prominent eosinophilic infiltration, and were all found around the hepatic hilum. In addition, venous occlusion with little inflammation and cholangitis without periductal fibrosis were frequently observed in the fibrohistiocytic type, whereas obliterative phlebitis and cholangitis with periductal fibrosis were common features of the lymphoplasmacytic type. Interestingly, IgG4-positive plasma cells were significantly more numerous in the lymphoplasmacytic than fibrohistiocytic type. However, two of the fibrohistiocytic inflammatory pseudotumors had relatively many IgG4-positive plasma cells. In conclusion, hepatic inflammatory pseudotumor could be classified into two types based on clinicopathological characteristics. The lymphoplasmacytic type is unique, and could belong to the so-called IgG4-related diseases. In contrast, the fibrohistiocytic type might still be a heterogeneous group of disorders. This latter type seems pathologically different from IgG4-related disease, although cases with relatively abundant IgG4-positive plasma cells should be differentiated from IgG4-related disease with secondary histopathologic modifications.

Overexpression of GRP78 and GRP94 are markers for aggressive behavior and poor prognosis in gastric carcinomas

Glucose-related proteins (GRPs) are ubiquitously expressed in endoplasmic reticulum and able to assist in protein folding and assembly; consequently, they are considered as molecular chaperones. GRP78 and GRP94 expression was induced by glucose starvation and up-regulated in the malignancies. To clarify the roles of both molecules in tumorigenesis and progression of gastric carcinomas, immunohistochemistry was used on tissue microarray containing gastric carcinomas, adenomas, and nonneoplastic mucosa using the antibodies against GRP78 and GRP94, with a comparison of their expression with clinicopathological parameters of carcinomas. Gastric carcinoma cell lines (MKN28, AGS, MKN45, KATO-III, and HGC-27) were studied for both proteins by immunohistochemistry and Western blot. There was more expression of both proteins in gastric carcinoma and adenoma than in nonneoplastic mucosas (P < .05). All gastric carcinoma cell lines showed their expression at different levels. They were positively correlated with tumor size, depth of invasion, lymphatic and venous invasion, lymph node metastasis, and Union Internationale Contre le Cancer staging (P < .05), with positive relationship between both proteins (P < .05). Univariate analysis indicated the postsurgical cumulative survival rate of patients with positive GRP78 or GRP94 expression to be lower than that in those without GRP78 or GRP94 expression (P < .05), but the close link disappeared if stratified according to depth of invasion (P > .05). Multivariate analysis showed that age, depth of invasion, lymphatic invasion, lymph node metastasis, Union Internationale Contre le Cancer staging, and Lauren classification (P < .05), but not GRP78 and GRP94 expression, were independent prognostic factors for carcinomas (P > .05). Up-regulated expression of GRP78 and GRP94 was possibly involved in pathogenesis, growth, invasion, and metastasis of gastric carcinomas. They were considered objective and effective markers for the aggressive behavior and poor prognosis in gastric carcinomas.

Biliary cystic tumors with bile duct communication: a cystic variant of intraductal papillary neoplasm of the bile duct.

Biliary cystic tumors, which are also called biliary cystadenoma and cystadenocarcinoma, are thought to be a heterogeneous disease entity, and some of them are known to show a luminal communication to the bile duct. In this study, we examined the clinicopathological features of nine cases of biliary cystic tumors with bile duct communication. They were composed of five males and four females with an average age of 67 years (52–84 years). They were multilocular (eight cases) or unilocular (one case), and all cases contained mucinous fluid. A direct luminal communication with the bile ducts was identified in five cases on preoperative or intraoperative cholangiographies. Biliary cystic tumors examined in this study were histologically adenoma (one case), adenocarcinoma in situ (six cases), and adenocarcinoma associated with microinvasive mucinous carcinoma (two cases). One case of adenocarcinoma in situ also had the adenoma component (adenocarcinoma in adenoma). Dysplastic mucinous epithelium proliferated in flat, micropapillary and papillary fashions within the intracystic spaces. Intraepithelial neoplasm was observed within non-dilated adjacent bile ducts, suggesting a direct luminal communication between the cystic tumors and the bile duct. Ovarian-like stroma was not observed in their walls in any cases. Immunohistochemically, seven cases expressed MUC1 or MUC2 in the neoplastic biliary epithelium. All cases except one were alive without any evidences of tumor recurrence after total excision (3–156 months after surgery). These clinicopathological features resembled those of intraductal papillary neoplasm of the bile duct, which had been reported as a biliary counterpart of pancreatic intraductal papillary mucinous neoplasm. In conclusion, biliary cystic tumors with bile duct communication could be regarded as intraductal papillary neoplasm with a prominent cystic dilatation of the bile duct and mucin retention, rather than true biliary cystic neoplasms.

Mixed-type gastric carcinomas exhibit more aggressive features and indicate the histogenesis of carcinomas.

To investigate the pathobiological behaviors of gastric mixed-type (MT) carcinomas and gastric carcinogenesis, the clinicopathological characteristics of MT carcinomas were analyzed and compared with intestinal-type (IT) and diffuse-type (DT) carcinomas. The expression of Ki-67, caspase-3, p53, fragile histine triad (FHIT), maspin, extracellular matrix metalloproteinase inducer (EMMPRIN), vascular growth factor (VEGF), MUC-2, 4, 5AC and 6, CD44, E-cadherin, β-catenin, and phosphorylated glycogen synthase kinase 3β-ser9 (P-GSK3β-ser9) was examined on tissue microarrays using immunohistochemistry. It was found that MT carcinomas exhibited large size, deep invasion, frequent local invasion, and lymph node metastasis in comparison with IT and DT carcinomas (p < 0.05). All the markers except MUC-5AC showed higher expression in IT than DT carcinomas (p < 0.05). The expression of maspin, EMMPRIN, VEGF, MUC-4, and membrane E-cadherin was stronger in MT intestinal than diffuse component (p < 0.05). Immunoreactivities to Ki-67, EMMPRIN, and VEGF were weaker in IT carcinoma than in the MT intestinal portion (p < 0.05), while the opposite was true for CD44, MUC-2, and MUC-6 (p < 0.05). The MT diffuse component displayed a higher expression of FHIT, VEGF, and P-GSK3β-ser9 than DT carcinoma (p < 0.05). The accumulative survival rate of the IT carcinoma patients was higher than the other types (p < 0.05). The invasive depth, venous invasion, lymph node, peritoneal or liver metastasis, and Laurens classification were independent prognostic factors for gastric carcinomas (p < 0.05). These findings suggested that MT carcinomas were also indicated to be more aggressive than IT and DT carcinomas. Significant differences were observed in the proliferation, apoptosis, angiogenesis, mucin secretion, and cell adhesion between IT and DT carcinomas, whereas only a few of these characteristics showed differences between the MT intestinal and diffuse parts, thus suggesting that both the MT components might originate from the stem cells with similar genetic traits, but follow different histogenic pathways.

Podoplanin is a useful diagnostic marker for epithelioid hemangioendothelioma of the liver

Podoplanin, which is immunoreactive to D2-40 antibody, is reportedly expressed in lymphatic vessels in non-neoplastic tissues, and also in vascular and non-vascular tumors. However, its expression in non-neoplastic and neoplastic liver tissues has not been well documented. In this study, we examined podoplanin expression in specimens from 10 normal livers and 73 cases of liver tumors: hemangioma (16 cases), epithelioid hemangioendothelioma (9 cases), angiosarcoma (4 cases), angiomyolipoma (7 cases), hepatocellular carcinoma (11 cases), intrahepatic cholangiocarcinoma (11 cases), and metastatic liver cancer (15 cases). We compared levels of podoplanin and other endothelial markers (CD31, CD34, and factor VIII) in liver tumors. In the normal liver, podoplanin was expressed in lymphatic endothelium, nerve fibers, and mesothelium in the hepatic capsule, but not observed in any cells within hepatic lobules. Among liver tumors, podoplanin was specifically expressed in seven of nine cases (78%) of epithelioid hemangioendothelioma but not in other hepatic tumors. The expression of CD31, CD34, and factor VIII was observed in endothelial cells in all cases of hemangioma, epithelioid hemangioendothelioma, angiosarcoma, and angiomyolipoma with one exception, a case of epithelioid hemangioendothelioma which was without CD31 expression. Interestingly, the intensity of podoplanin expression was negatively correlated with the expression of CD34 and factor VIII. In conclusion, podoplanin would be useful as a diagnostic marker for epithelioid hemangioendothelioma in liver tumors.

Immunohistochemical study of hepatic angiomyolipoma

An immunohistochemical study was performed on nine hepatic anglomyolipomas (AML) found in eight patients. Histologically, the tumors were fundamentally composed of the three heterogeneous tissue components of blood vessels, smooth muscle cells (SMC), and fat cells, although the proportions and distributions were quite variable from tumor to tumor and from area to area in the same tumor. Additionally, cellular pleomorphism and atypia with occasional bizarre giant cells were found in the SMC component. This histologic feature might lead to a mistaken diagnosis of malignant neoplasm, and pathologists should therefore be aware of the broad histologic spectrum of hepatic AML. However, the Immunostalning patterns were basically the same in all nine tumors. All tumor components were negative for epithelial membrane antigen (EMA) and for cytokeratin. The spindle‐shaped SMC component of the tumor was occasionally positive for vimentin, desmin and alpha‐smooth muscle actin, whereas epithelioid SMC were negative for all three. Both the epithelioid and spindle‐shaped SMC were occasionally positive for S‐100 and neuron‐specific enolase. All types of SMC in the tumor, whether spindle, epithelioid, intermediate or pleomorphic SMC, were strongly positive for HMB‐45, a melanoma‐specific monoclonal antibody. Fat cells were occasionally positive for S‐100. Endothelial cells were positive for factor Vlll‐associated antigen. Among hepatic tumors HMB‐45 reactivity is, so far as we know, found exclusively in the SMC of AML, and the HMB‐45 reactivity of a hepatic tumor is thus clearly an important piece of information in the diagnosis of AML

Clinicopathologic study of mixed adenoneuroendocrine carcinomas of hepatobiliary organs

Neuroendocrine neoplasms in hepatobiliary organs are very rare, but several cases of mixed adenoneuroendocrine carcinoma (MANEC) have been reported. In this study, we characterized the neuroendocrine component of biliary MANEC. A total of 274 cases of biliary cancer including 17 intrahepatic cholangiocarcinomas (CCs), 15 hepatic hilar CCs without preceding hepatobiliary disease, 55 hepatic hilar CCs with hepatolithiasis, 49 gallbladder cancers, 53 extrahepatic CCs, and 85 hepatocellular carcinomas were examined for a neuroendocrine component using immunohistochemistry with neuroendocrine markers (chromogranin A and synaptophysin). In the MANEC cases, in addition to a close histological examination, the proliferative activity and the expression of somatostatin receptor 2A were also evaluated. In addition to an ordinary adenocarcinoma, a neuroendocrine component occupying more than 30% of the entire tumor was also found in 4% (2/55 cases) of hepatic hilar cholangiocarcinomas with hepatolithiasis, 10% (5/49 cases) of gallbladder cancers, and 4% (2/53 cases) of extrahepatic cholangiocarcinomas, but not in the intrahepatic cholangiocarcinomas, hilar cholangiocarcinomas without preceding hepatobiliary disease, and hepatocellular carcinomas. Two cases were positive for somatostatin receptor 2A. The adenocarcinoma components were predominately located at the surface of the tumors, and the majority of stromal and vascular invasion and lymph node metastasis involved neuroendocrine components, showing the features of neuroendocrine tumor G2 or neuroendocrine carcinomas (NECs). NEC components showed higher proliferative activity on Ki67 immunostaining, compared to the adenocarcinoma components. Biliary MANECs are found in hepatic hilar cholangiocarcinomas with hepatolithiasis, gallbladder cancers, and extrahepatic cholangiocarcinomas and show a characteristic histology. Since the neuroendocrine component in biliary MANEC defines the prognosis, it is important to identify it and consider the indications for adjunctive therapy with somatostatin analogues.