Immunostaining for polycomb group protein EZH2 and senescent marker p16INK4a may be useful to differentiate cholangiolocellular carcinoma from ductular reaction and bile duct adenoma.

Intrahepatic cholangiocarcinoma arising in chronic advanced liver disease sometimes contains a component of cholangiolocellular carcinoma. Bile duct adenoma, a benign tumor/tumorous lesion and ductular reaction, is also composed of bile ductular cells, and the differential diagnosis is sometimes difficult. We have previously reported that cholangiolocellular carcinoma showed overexpression of a polycomb group protein EZH2, which participates in bypass/escape from cellular senescence during carcinogenesis. In contrast, the ductular reaction showed high expression of senescence-associated p16(INK4a). In this study, we examined whether immunostaining for EZH2 and p16(INK4a) is useful for differential diagnosis among cholangiolocellular carcinoma, bile duct adenoma, and ductular reactions. Subjects included 33 patients with intrahepatic cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma with components of cholangiolocellular carcinoma and 16 patients with bile duct adenoma. The expressions of EZH2 and p16(INK4a) were examined immunohistochemically. The expression of EZH2 was seen in all cases of cholangiolocellular carcinomas, but it was not observed in bile duct adenomas and ductular reactions, which were seen around carcinomas in 80% of cases. The extensive expression of p16(INK4a) was seen only in 4 cases of cholangiolocellular carcinomas (12%). In contrast, the expression of p16(INK4a) was seen in 13 cases (81%) of bile duct adenomas and in all cases of ductular reactions. The borderline between the component of cholangiolocellular carcinoma and the surrounding ductular reaction was clearly highlighted by the reverse expression pattern of EZH2 and p16(INK4a) in 69% of cases. In conclusion, immunostaining for EZH2 and p16(INK4a) may be useful for differential diagnosis among cholangiolocellular carcinomas, bile duct adenomas, and ductular reactions.

Primary liver carcinoma in genetic hemochromatosis reveals a broad histologic spectrum.

Hepatocellular carcinoma (HCC) is a well-known complication of genetic hemochromatosis (GH). However, the frequency of primary liver carcinoma (PLC) with biliary differentiation, such as cholangiocarcinoma (CC) and combined hepatocholangiocarcinoma (CHCC), in GH remains unclear We analyzed the histologic type of 20 PLCs occurring in the background of GH; all patients were homozygotic for the C282Y mutation. Ten were depleted of iron by successive phlebotomies, while the remaining 10 were untreated. Histologically, 13 cases were classified as HCC, 3 as CC, and 4 as CHCC. Immunohistochemical detection of Hep Par 1, cytokeratin 19 (CK19), and MUC1 supported this classification; PLC with biliary differentiation was immunoreactive for MUC1 in 86% (6/7) of cases and for CK19 in 100% (7/7) of cases. The nontumoral liver exhibited no cirrhosis or extensive fibrosis in 6 cases. Von Meyenburg complexes were present in 11 cases and intraparenchymal bile duct adenomas in 3. These data suggest that PLCs in patients with GH present a wide histologic spectrum, with tumors showing frequent biliary differentiation; may arise on a nonfibrotic or a cirrhotic liver; and often are associated with Von Meyenburg complexes and to a lesser extent with bile duct adenomas.

A case report of biliary cystadenoma and cystadenocarcinoma.

Three cases of intrahepatic biliary cystadenoma with mesenchymal stroma and one case of biliary cystadenocarcinoma are presented. Their immunohistochemical features and the surgical treatment are discussed together with a brief review of the literature. The benign cystadenomas stained positive for cytokeratin and CA 19-9 in the epithelium of the cyst wall. Mesenchymal stromal cells were strongly positive for a-SMA and moderately positive for desmin. The epithelium of the cystadenocarcinoma, however, was positive only for cytokeratin and the stroma only for a-SMA. Our findings indicate that biliary cystadenomas seem to be of primitive hepatobiliary origin. Furthermore, the malignant variant cystadenocarcinoma may loose its immunoreactivity for CA 19-9 and desmin.

Biliary cystadenoma of cats.

Published surveys of feline neoplasia have not specifically included biliary cystadenoma, and there is only one case report in the literature. This report is a compilation of 13 feline cases and provides a description of clinical, pathologic, immunohistochemical, and ultrastructural aspects of biliary cystadenoma as well as a discussion of comparative pathology of biliary cystadenoma in human beings and speculative histogenesis.

Intrahepatic cholangiocarcinoma with sarcomatous change. Clinicopathologic and immunohistochemical evaluation of seven cases.

BACKGROUND: Although there have been a few reports dealing with the sarcomatous changes of intrahepatic cholangiocarcinoma, its clinicopathologic features as well as immunohistochemical nature remain obscure. METHODS: Among 155 cases of intrahepatic cholangiocarcinoma, 7 cases of sarcomatous cholangiocarcinoma were chosen. Immunohistochemical studies using the avidin-biotin-peroxidase complex method were performed on these cases. RESULTS: The tumor showed both mucin-producing adenocarcinoma areas and sarcomatous areas, the latter being predominant in three cases and focal in the other four. All the sarcomatous areas consisted of atypical spindle cells arranged in sheets or bundles. Pleomorphic giant cells were observed in some sarcomatous components in five cases. Immunohistochemical staining for keratin and epithelial membrane antigen revealed apparent positivity in the sarcomatous components of five cases. The patients with these tumors showed aggressive intrahepatic spreading and widespread metastasis of the sarcomatous cells, and demonstrated poorer prognosis than those with ordinary cholangiocarcinoma, with one exception, a patient who remained disease-free for 3 years after surgery. CONCLUSIONS: These findings favor the possible epithelial origin of sarcomatous cells. Radical operation would be necessary for patients with this special type of cholangiocarcinoma.

Immunohistochemical study of mucin carbohydrates and core proteins in hepatolithiasis and cholangiocarcinoma.

The expression of mucin carbohydrates [Tn, sialosyl-Tn(STn), and T antigens] and core proteins [MUCI-apomucin-related antigen (ARA) and MUC2-ARA] was examined immunohistochemically in tissues from 40 patients with hepatolithiasis and 26 patients with intrahepatic bile-duct carcinoma. Tn and STn antigens were expressed in most of the carcinomas, and were also often expressed in the atypical bile-duct epithelium of the patients with hepatolithiasis or carcinoma, whereas they were rarely or never expressed in the normal bile duct, suggesting that they are effective tumor markers. T antigen was less useful as a marker for intrahepatic bile-duct carcinoma or the atypical epithelium, because it was expressed in normal bile-duct of some cases. Regarding the expression of ARAs in the carcinomas, non-invasive bile-duct cyst adenocarcinomas with favorable prognosis either expressed no MUCI-ARA with [DF3(-), MUSEII(-) and 139H2(-)] staining pattern or expressed MUCI-ARA with [DF3(-), MUSEII(+) and 139H2(+)] staining pattern. However these tumors often expressed MUC2-ARA with [anti-MRP(+) and CCP58(+)] staining pattern. In contrast, most invasive non-papillary cholangiocarcinomas with poor prognosis expressed MUCI-ARA with [DF3(+), MUSEII(+) and 139H2(+)] staining pattern, but expressed no MUC2-ARA with [anti-MRP(-) and CCP58(-)] staining pattern. These results suggests that different apomucins are produced by bile-duct cystadenocarcinomas and cholangiocarcinomas with differing prognosis. Furthermore, expression of Tn and STn antigens is a useful indicator of malignancy in the intrahepatic duct.

Comparative immunohistochemical study of primary and metastatic carcinomas of the liver.

Distinguishing primary hepatocellular carcinoma (HCC) from metastatic carcinomas to the liver is often difficult, if not impossible, particularly in needle biopsy and fine-needle aspiration specimens. In an attempt to identify a specific immunohistochemical profile that would distinguish HCC from metastatic carcinomas, we studied 56 HCCs, 8 cholangiocarcinomas, and 24 metastatic adenocarcinomas with monoclonal antibodies to alpha-fetoprotein (AFP), keratin (AE1, AE3, and CAM5.2), Leu-M1, human milk fat globule (HMFG-2), tumor-associated glycoprotein-72(B72.3), epithelial specific membrane antigen (Ber-EP4), and BCA-225 (CU-18). Both monoclonal and polyclonal (mCEA and pCEA) antibodies to carcinoembryonic antigen also were used. Metastatic adenocarcinomas were often positive for CU-18(71%), Leu-M1 (75%), B72.3 (50%), HMFG-2 (67%), Ber-EP4(83%) and mCEA(71%). Using these antibodies, the frequency of positivity for HCC was 9%, 16%, 11%, 20%, 36%, and 11%, respectively. CU-18 was the only monoclonal antibody in which there was a significant difference in positive rates between HCC and metastatic adenocarcinomas. Most HCCs (71%) revealed a bile canalicular staining pattern with pCEA. Because this staining pattern was absent in metastatic carcinomas, pCEA appears to be useful in confirming a diagnosis of HCC. AE1, AE3 and CAM5.2 antibodies were not useful in distinguishing HCC from metastatic carcinomas. Each cholangiocarcinoma shared a staining profile similar to that of metastatic carcinomas.

Cell kinetic and morphological studies of human cholangiocellular carcinoma.

We investigated the cell kinetics and morphologies of cholangiocellular carcinoma (CCC) using 48 autopsied or surgically resected cases (47 were adenocarcinoma and the remaining adenosquamous cell carcinoma), all of which were formalin-fixed and paraffin-embedded. Cell kinetics were analyzed by counting the number of argyrophilic nucleolar organizer regions (AgNOR) using immunostaining of proliferating cell nuclear antigens (PCNA) and flow cytometric DNA analysis. Dedifferentiation of CCC was positively correlated with AgNOR number (2.22 +/- 0.21 in well differentiated, 3.66 +/- 0.85 in moderately differentiated and 4.17 +/- 0.49 in poorly differentiated adenocarcinomas, respectively). In 22 cases, the labeling index (LI) of PCNA was higher in moderately and poorly differentiated adenocarcinomas (24.0 +/- 2.35 and 26.0 +/- 4.89, respectively) than in well differentiated ones (10.8 +/- 2.14). A majority of well differentiated ones were diploid, while aneuploidy prevailed in moderately to poorly differentiated ones. These data suggest that cell proliferative indices and nuclear DNA analysis of CCC accurately reflect their histological grading. The anatomical location of CCC along the biliary tree had no relation to either of the cell kinetic data. In autopsy cases, the patients with organ and lymph node metastases tended to show a higher DNA index and aneuploidy. This study implies that a combination of several cell kinetic data is valuable for the evaluation of the biological behaviors of CCC, and also supports further studies of cell kinetics of CCC using small-sized biopsy specimens, as a prognostic indicator.

Immunolocalization of ras oncogene p21 in human liver diseases.

Fifty-five cases representing a spectrum of disease states of the human liver and 10 normal liver controls were examined for the presence of the ras oncogene product p21. Conventional formalin-fixed, paraffin-embedded sections were immunostained by the avidin-biotin complex method with the broadly reactive ras p21 monoclonal antibody (Mab) RAP-5. The specificity of the reactions was confirmed by immunostaining selected samples with Mab Y13-259. In the normal liver, virtually no hepatocytic immunostaining was noted. Variable, often extensive, and convincing immunoreactions were noted in diverse forms of hepatitis, cirrhosis, and allograft rejection; the strongest immunostaining was found in samples of focal nodular hyperplasia. Hepatic adenomas and hepatocellular carcinomas showed unevenly distributed, moderate to weak reactions or no reaction at all; cholangiocarcinomas did not immunostain. In reactive but non-transformed liver cell populations, enhanced p21 ras reactions seemed to correlate with the severity of the injury and the intensity of the proliferative response. The uneven and comparatively weak ras p21 reactions noted in adenomas and carcinomas suggest that this oncogene product may be involved only transitorily in their transformation processes and possibly may not be involved in certain variants thereof.

Extensive portal tumor thrombi with portal hypertension in an autopsy case of intrahepatic cholangiocarcinoma.

Vascular invasion is not a prominent feature of cholangiocarcinoma (CCC), in contrast to hepatocellular carcinoma (HCC), which frequently shows extensive vascular tumor thrombi. We report an autopsy case of CCC with extensive portal tumor thrombi and portal hypertension. A 57-yr-old man presented with abdominal pain. Liver imaging revealed no tumors, but showed intrahepatic portal venous obstruction. HCC with portal tumor thrombi was suspected clinically. His clinical course was rapid; he died of hepatic failure 50 days after admission. At autopsy, the liver (2,700 g) was studded with diffuse whitish yellow granular areas with flecks of coalescent granules. Intrahepatic portal veins were diffusely occluded by tumor thrombi. Microscopically, the tumor was poorly differentiated adenocarcinoma with mucin; tumor cells were immunohistochemically positive for carcinoembryonic antigen, CA 19-9, DU-PAN-2, and biliary type cytokeratins, but negative for alpha-fetoprotein. Tumor cells were diffuse in the liver, and there were numerous tumor thrombi in the small portal veins. Hepatic veins and small arteries were occasionally occluded by tumor thrombi. There was ascites, splenomegaly and tumor thrombi in the gastric and esophageal veins, suggesting that portal hypertension had been present. This tumor seemed to have marked affinity to invade portal veins. It must be stressed that there are CCCs with extensive portal tumor thrombi and resultant portal hypertension.

Two new human cholangiocarcinoma cell lines and their cytogenetics and responses to growth factors, hormones, cytokines or immunologic effector cells.

Two new human cholangiocarcinoma (CC) cell lines (CC-SW-I and CC-LP-I) were established and maintained in culture for 2 years. Histologically, both original liver tumors were adenocarcinomas, and the cell lines exhibited morphologic features of moderately differentiated adenocarcinoma. Immunohistochemistry showed that both cell lines were strongly positive for cytokeratin AEI but negative for carbohydrate tumor-associated antigen, CA19-9. Ultrastructural analysis of both cell lines showed the presence of tight junctional complexes and focally formed microvilli. Both CC cell lines were tumorigenic in nude mice. Cytogenetic analysis showed that both cell lines expressed highly aneuploid karyotypes with numerous structural and numerical deviations. CC-SW-I was hypodiploid with numerous chromosome losses and structural rearrangements, while CC-LP-I was hyperdiploid and displayed multiple additional chromosomes. Doubling times for the CC-SW-I and CC-LP-I cell lines in the presence of 15% fetal bovine serum were 72 hr and 180 hr, respectively. Growth of the CC-SW-I cell line was significantly stimulated in the presence of insulin, while that of the CC-LP-I cell line was significantly augmented by epidermal growth factor (EGF). In contrast, dexamethasone strongly inhibited proliferation of both cell lines in a dose-dependent manner. Among various recombinant cytokines examined for effects on growth or surface antigen expression on CC cell lines, only interleukin I-beta (ILI-beta) strongly inhibited growth of the CC-LP-I cell line, while interferons (IFNs) or tumor necrosis factor-alpha (TNF-alpha) were mildly inhibitory. Both tumor cell lines were resistant to natural killer (NK) cells but sensitive to lymphokine-activated killer (LAK) cells. Preincubation of tumor cells with IFN-gamma, IFN-alpha or TNF-alpha significantly decreased the susceptibility of each tumor cell line to lysis by LAK cells, and the change in sensitivity did not correlate with the expression of HLA antigens or intercellular adhesion molecule-I (ICAM-I) on the surface of tumor cells. These 2 CC cell lines are expected to provide valuable information about cell biology of human CC.

In vivo and in vitro 31P magnetic resonance spectroscopy of focal hepatic malignancies.

In vivo 31P magnetic resonance spectroscopy (MRS) was undertaken in 28 healthy adult individuals and 32 patients with hepatic malignancies of varying histology, using chemical shift imaging techniques. The mean peak area ratio (total range) of phosphomonoester (PME) to phosphodiester (PDE) in the health adult group was 0.23 (0.15-0.41). The mean (total range) PME/PDE ratio of the total patient group was 0.68 (0.15-2.38), which was significantly elevated (P less than 0.001) compared to the mean of the healthy adult group. Liver biopsies, obtained at operation, were analysed using high-field in vitro MRS techniques in order to identify the contributions of aqueous-soluble metabolites to the multicomponent PME and PDE in vivo signals. Concentrations of phosphorylethanolamine (PE), phosphorylcholine (PC), glycerophosphorylethanolamine (GPE) and glycerophosphorylcholine (GPC) were measured. The in vitro spectrum of six samples of liver of normal histological appearance all showed a similar pattern of PE, PC, GPE and GPC. The in vitro spectrum of seven liver tumours of differing histology all showed an increase in PE and PC signals and a decrease in GPC and GPE signals. The in vitro results were compared with in vivo findings in five patients. The increase in PME/PDE observed in vivo represented, in part, an increase in PE and PC in the PME region and a decrease in GPE and GPC in the PDE region.

Histochemical and immunohistochemical analyses of primary carcinoma of the liver.

Hematoxylin and eosin (H-E) stained liver sections of 47 autopsy cases of hepatic malignancies were examined. There were 43 cases of hepatocellular carcinoma (subtypes of 30 trabecular, 7 solid, 5 pseudoglandular, and one scirrhous carcinoma), 3 of cholangiocellular carcinoma and one of mixed carcinoma. After immunohistochemical staining, benign hepatocytes reacted positively with anti-epithelial membrane antigen (EMA). Hepatocellular carcinoma cells reacted more weakly than benign hepatocytes. It was noted that the microtubular structure, which could not be demonstrated even by alcian blue or cationic ferric hydroxide colloid stabilized with cacodylate (Fe-CaC), was clearly detected with anti-EMA. The EMA-positive microtubular structures may indicate terminal cholangiolar differentiation. Based on EMA, seven more cases formerly classified as hepatocellular carcinoma by H-E were reclassified as mixed carcinoma, totaling eight (17.0%). The histologic classification of "mixed carcinoma" has been 1.5 to 2.0% of primary liver cancers in Japan, but we suggest there may be more cases of "mixed carcinoma" identified in the future. In conclusion, we emphasize that EMA staining is useful for more accurate classification of hepatic tumors.

Mucosal dysplasia of the liver and the intraductal variant of peripheral cholangiocarcinoma in hepatolithiasis.

Four cases are reported of the intraductal variant of peripheral cholangiocarcinoma among surgical specimens from 32 cases of hepatolithiasis. The cancers arose from the periphery of the stone-containing bile duct and spread chiefly along the luminal surface. Microscopically, these tumors showed papillary proliferation and therefore were diagnosed as the intraductal spreading type of peripheral cholangiocarcinoma. Mucosal dysplasia also was noticed in the vicinity of the tumors. In six other cases, mucosal dysplasia was observed in the periphery of the stone. Immunohistochemically, anti-CA 19-9 staining was observed diffusely in the cytoplasm of dysplastic lesions and carcinomas. Anti-carcinoembryonic antigen staining was restricted to the luminal surface and/or the supranuclear region of the cytoplasm in carcinomas. It was not identified in dysplastic cells. These results suggest that the mucosal dysplasia occasionally observed near stones is a precursor of the intraductal spreading type of peripheral cholangiocarcinoma in the presence of hepatolithiasis. The authors hypothesize that the lining epithelium of the large bile duct, when persistently exposed to biochemically altered bile, may undergo a carcinomatous transformation through a stage of mucosal dysplasia.

Isolation and immunohistochemical characterization of a pancreatic carcinoma-associated monoclonal antibody.

The aim of this study was to define a cellular antigen associated with human pancreatic ductal carcinoma, and to study its distribution in a large panel of malignant, benign, and normal tissues. For this purpose, monoclonal antibodies were generated against a postmicrosomal fraction of fresh human pancreatic cancer. One such antibody, LD-B1, reacted strongly with 95% of cases of primary and metastatic pancreatic ductal carcinomas. It also immunostained gallbladder carcinomas and cholangiocarcinomas. By contrast, it exhibited focal or weak reactivity to 10% of other types of common malignant tumors. On normal pancreas, staining was observed in ductal and centriacinar cells, but not in acinar or endocrine cells. In chronic pancreatitis, ductal staining intensity increased proportionally with the degree of cellular atypia. The antigen was also detected in gallbladder epithelium, bile ducts, ductal epithelium of sweat glands and salivary glands, and focally in a few other normal nonpancreatic tissues. These results suggest that LD-B1 MoAb can be used in immunohistochemical studies as a marker of pancreatic adenocarcinoma.