Kazuhide Shimamatsu

Proposal of histological criteria for intraepithelial atypical/proliferative biliary epithelial lesions of the bile duct in hepatolithiasis with respect to cholangiocarcinoma: Preliminary report based on interobserver agreement

Biliary lining epithelia of the bile ducts in biliary diseases are known to have intraepithelial atypical/proliferative lesions related to the development of cholangiocarcinoma. The purpose of the present study was to determine the histological criteria for these lesions based on interobserver agreement. Digital images of 30 intraepithelial atypical/proliferative lesions in the stone‐containing intrahepatic bile ducts of hepatolithiasis (30 cases) were sent to 10 pathologists. At first, 10 pathologists made a diagnosis (either of reactive/regenerative change, low‐grade or high‐grade biliary intraepithelial neoplasia (BilIN‐1 and BilIN‐2), or in situ carcinoma (BilIN‐3)) based on their own criteria. The histological criteria for these four lesions were then determined, and the digital images of the same lesions with proposed criteria were re‐distributed. Interobserver agreement on these four lesions was slightly improved (κ = 0.44, first diagnosis; 0.49, second diagnosis) and intraobserver agreement was ‘almost perfect’ (κ = 0.82 at both first and second diagnosis). Interobserver agreement between BilIN‐1 and BilIN‐2 and that between BilIN‐2 and BilIN‐3 were ‘moderate’, although the agreement between regenerative/reactive change and BilIN‐1 was ‘fair’. In this report, we propose histological criteria for reactive/regenerative change, BilIN‐1, BilIN‐2 and BilIN‐3. Improvement of interobserver agreement suggests their applicability in diagnostic and research fields.

Diagnostic Accuracy of Imaging for Liver Cirrhosis Compared to Histologically Proven Liver Cirrhosis

Objective: To evaluate the diagnostic accuracy of liver cirrhosis by imaging modalities, including CT, MRI and US, compared to results obtained from histopathological diagnoses of resected specimens. Materials and Methods: CT, MRI and US examinations of 142 patients with chronic liver disease who underwent surgery for complicated hepatocellular carcinoma (<3 cm in diameter) in 10 institutions were blindly reviewed in a multicenter study by three radiologists experienced in CT, MRI and US. The images were evaluated for five imaging parameters (irregular or nodular liver surface, blunt liver edge, liver parenchymal abnormalities, liver morphological changes and manifestations of portal hypertension) using a severity scale. The diagnostic imaging impression score was also calculated. Patients were histologically classified into chronic hepatitis (CH; n = 54), liver cirrhosis (LC; n = 71) and pre-cirrhosis (P-LC; n = 17) by three pathologists, independently, who reviewed the resected liver specimens. The results of the three imaging methods were compared to those from histological diagnoses, and a multivariate analysis (stepwise forward logistic regression analysis) was performed to identify independent predictive signs of cirrhosis. The diagnostic efficacies for LC and early cirrhosis were also compared among CT, MRI and US using a receiver-operating characteristic (ROC) curve analysis. Results: The differences in the five imaging parameters evaluated by CT, MRI and US between LC and CH were statistically significant (p < 0.001) except for the manifestations of portal hypertension on US. Irregular or nodular surface, blunt edge or morphological changes in the liver were selected as the best predictive signs for cirrhosis on US whereas liver parenchymal abnormalities, manifestations of portal hypertension and morphological changes in the liver were the best predictive signs on MRI and CT by multivariate analysis. The predictive diagnostic accuracy, sensitivity and specificity in discriminating LC from CH based on the best predictive signs were 71.9, 77.1 and 67.6% by CT; 67.9, 67.5 and 68.3% by MRI, and 66.0, 38.4 (lower than CT and MRI, p =0.001) and 88.8% (higher than CT and MRI, p =0.001)by US. According to the imaging impression scoring system, diagnostic accuracy, sensitivity and specificity were 67.0, 84.3 and 52.9% by CT; 70.3, 86.7 and 53.9% by MRI, and 64.0, 52.4 (lower than CT and MRI, p =0.0001) and 73.5% (higher than CT and MRI, p < 0.003) by US. ROC analysis showed that MRI and CT were slightly superior to US in the diagnosis of LC but no statistically significant difference was found between them. For the pathological diagnosis of P-LC, cirrhosis was diagnosed in 59.5, 46.7 and 41.7% of the P-LC cases by US, CT and MRI, respectively, with no significant difference among these methods. Conclusion: US, CT and MRI had different independent predictive signs for the diagnosis of LC. MRI and CT were slightly superior to US in predicting cirrhosis, especially regarding sensitivity. Noninvasive imaging techniques play an important role in the diagnosis of cirrhosis, especially in the evaluation of P-LC.

High prevalance of TT virus infection in Japanese patients with liver diseases and in blood donors

BACKGROUND/AIMS Although a novel DNA virus, TT virus (TTV), has been isolated from a patient with cryptogenic post-transfusion hepatitis, its pathogenic role remains unclear. To elucidate its prevalence and clinical impact in patients with liver diseases, the presence of TTV DNA was assessed in patients with liver diseases and blood donors (BDs) in Japan using two primer sets, one conventional and the other new and highly sensitive. METHODS We studied 261 samples, 72 with chronic hepatitis associated hepatitis C virus (HCV-CH), 57 with hepatocellular carcinoma associated HCV (HCV-HCC), 12 with HCC without either HCV or hepatitis B virus (NBNC-HCC), and 120 of BDs. RESULTS Using two primer sets, TTV DNA was detected in 68 (94.4%), 53 (93.0%), 12 (100%), and 98 (81.7%) HCV-CH, HCV-HCC, NBNC-HCC, and BDs, respectively. The prevalence was not significantly different between HCV-CH and HCV-HCC, or between HCV-HCC and NBNC-HCC. Comparison between patients with and without TTV revealed no significant differences in backgrounds or biochemical findings. Histopathological findings in patients with HCV-CH, and number, maximum diameter, and histological differentiation of HCC also did not demonstrate any relation to TTV infection. TTV strains can be divided into five groups using phylogenetic analysis, but no disease-specific group appears to exist. CONCLUSIONS Our data suggest that: 1) TTV is very prevalent among patients with liver diseases and even among BDs in Japan, 2) TTV infection does not impact on liver damage with HCV infection, and 3) TTV infection also does not affect the development or progression of HCC.

Hepatitis C virus RNA present in saliva but absent in breast‐milk of the hepatitis C carrier mother

In order to examine whether saliva and breast‐milk are mediators of the vertical transmission of hepatitis C virus (HCV) from an HCV carrier mother, serum, saliva, and breast‐milk samples from 11 HCV carrier mothers were collected at the time of delivery, and at approximately 1‐ to 3‐month intervals for as long as 30 months postpartum. Serum was also sampled from their children. All samples were analysed for the presence of HCV RNA, using the nested polymerase chain reaction method. No HCV RNA was detected in any breast‐milk samples. In saliva, HCV RNA was detected in four of the 11 mothers (36%). These four mothers also had liver function abnormalities. Hepatitis C virus RNA was not detected in any serum samples of the children, and all children had normal liver function. The children were monitored for periods from 2 to 44 months. During this period, there was no evidence of virus transmission. Breast‐milk is not likely to be a source of mother‐to‐child transmission of HCV. Maternal saliva may harbour HCV, but it may not result in infant infection.

Are bile duct lesions of primary biliary cirrhosis distinguishable from those of autoimmune hepatitis and chronic viral hepatitis? Interobserver histological agreement on trimmed bile ducts

BackgroundPrimary biliary cirrhosis (PBC) is histopathologically characterized by chronic nonsuppurative destructive cholangitis and ductopenia of interlobular bile ducts. Bile duct injury is also often encountered in chronic viral hepatitis (CVH) and in autoimmune hepatitis (AIH).MethodsIn this study, we performed interobserver agreement analysis on 90 injured bile ducts from liver specimens of PBC (17 cases), CVH (26 cases), and AIH (18 cases), with 30 bile ducts chosen from each disease group. Digital images of bile ducts with minimal periductal elements were recorded in CD-ROM format and sent to 14 observers (six special hepatopathologists, four local hepatopathologists, and four general pathologists). We analyzed the following issues: (1) diagnostic accuracy of PBC, based only on bile duct lesions; (2) classification of bile duct lesions in AIH cases as destructive cholangitis equivalent to PBC-associated injury, or not.ResultsThe diagnostic accuracy of PBC cases with severe bile duct injuries was very high (over 80%), although the accuracy in cases with only mild bile duct injuries was low (50% or less). For AIH, each observer classified 9 of the 30 bile ducts, on average, as destructive cholangitis.ConclusionsThis study revealed that 66.9% of PBC cases could be diagnosed based on trimmed bile ducts alone. Bile duct injury similar to that in PBC could be encountered in AIH.

Pathomorphological study of HCV antibody-positive liver cirrhosis

A morphological investigation was carried out to study the pathological features of liver cirrhosis caused by hepatitis C virus (HCV) infection. The materials consisted of liver specimens taken from 47 cases of anti‐HCV antibody‐positive liver cirrhosis (37 by surgery for hepatocellular carcinoma and 10 by autopsy), and from 21 cases of hepatitis B surface antigen‐positive liver cirrhosis as the control. Liver specimens containing more than 10 regenerative nodules were examined. In addition, a histometric study was conducted to determine the degree of fibrosis and the size of regenerative nodule using a computer image‐analysis system.

Intraductal neoplasm of the intrahepatic bile duct: Clinicopathological study of 24 cases

AIM To investigate the clinicopathological features of intraductal neoplasm of the intrahepatic bile duct (INihB). METHODS Clinicopathological features of 24 cases of INihB, which were previously diagnosed as biliary papillomatosis or intraductal growth of intrahepatic biliary neoplasm, were reviewed. Mucin immunohistochemistry was performed for mucin (MUC)1, MUC2, MUC5AC and MUC6. Ki-67, P53 and β-catenin immunoreactivity were also examined. We categorized each tumor as adenoma (low grade), borderline (intermediate grade), and malignant (carcinoma in situ, high grade including tumors with microinvasion). RESULTS Among 24 cases of INihB, we identified 24 tumors. Twenty of 24 tumors (83%) were composed of a papillary structure; the same feature observed in intraductal papillary neoplasm of the bile duct (IPNB). In contrast, the remaining four tumors (17%) showed both tubular and papillary structures. In three of the four tumors (75%), macroscopic mucin secretion was limited but microscopic intracellular mucin was evident. Histologically, 16 tumors (67%) were malignant, three (12%) were borderline, and five (21%) were adenoma. Microinvasion was found in four cases (17%). Immunohistochemical analysis revealed that MUC1 was not expressed in the borderline/adenoma group but was expressed only in malignant lesions (P = 0.0095). Ki-67 labeling index (LI) was significantly higher in the malignant group than in the borderline/adenoma group (22.2 ± 15.5 vs 7.5 ± 6.3, P < 0.01). In the 16 malignant cases, expression of MUC5AC showed borderline significant association with high Ki-67 LI (P = 0.0622). Nuclear expression of β-catenin was observed in two (8%) of the 24 tumors, and these two tumors also showed MUC1 expression. P53 was negative in all tumors. CONCLUSION Some cases of INihB have a tubular structure, and are subcategorized as IPNB with tubular structure. MUC1 expression in INihB correlates positively with degree of malignancy.

Simultaneous Hepatic Relapse of Non-Hodgkin’s Lymphoma and Hepatocellular Carcinoma in a Patient with Hepatitis C Virus-Related Cirrhosis

We report a 66-year-old man with hepatitis C virus (HCV)-related cirrhosis and simultaneous hepatic relapse of non-Hodgkin’s lymphoma (NHL) and of hepatocellular carcinoma (HCC). Although the liver is frequently involved by NHL, hepatic colocalization of NHL and HCC is rarely detected by imaging techniques. HCV has been suggested to be lymphotrophic as well as hepatotrophic, and therefore has attracted speculation about a causative role in some cases of lymphoma. The patient had a past history of cutaneous diffuse large B cell lymphoma (DLBCL) in concurrence with HCC 32 months previously. Complete remission (CR) had been maintained for both diseases until February 2004, when ultrasonography and computed tomography (CT) showed multiple liver tumors. Two of these, appearing hyperattenuating in the arterial phase of contrast-enhanced CT, were diagnosed histopathologically as HCC, and treated with radiofrequency ablation. The other tumors, hypoattenuating in the portal phase CT, were diagnosed histopathologically as DLBCL, and treated with cyclophosphamide, tetrahydropyranyl-Adriamycin, vincristine and prednisolone (THP-COP) in combination with rituximab. CR was achieved for both DLBCL and HCC. Given the previously demonstrated immune system tropism and perturbation by HCV, the virus might have contributed to the occurrence of the NHL as well as the HCC.

The utility of a novel antibody in the pathological diagnosis of pancreatic acinar cell carcinoma

Aims Acinar cell carcinomas (ACCs) are rare tumours of the exocrine pancreas accounting for about 1–2% of all pancreatic neoplasms in adults. It is therefore difficult to come across a large number of ACC cases in a single medical institution, and only a few serial studies have been published. Since ACCs present a wide variety of morphological patterns, immunohistochemical analysis is useful. In this study, the authors established a novel monoclonal antibody 2P-1-2-1 by means of a subtractive immunisation method. Methods Immunohistochemical staining was performed using 50 primary pancreatic tumors, including 7 ACCs, 7 neuroendocrine tumours (NETs), 5 solid-pseudopapillary neoplasms (SPNs), and 31 ductal carcinomas and organs other than the pancreas. Results Non-neoplastic acinar cells were stained diffusely, but epithelial cells of the pancreatic duct and the islets of Langerhans were not stained. In pancreatic tumours, all the seven ACCs were diffusely positive for the 2P-1-2-1 antibody. However, no positive staining was found in other pancreatic tumours including NETs, SPNs and ductal adenocarcinomas. The sensitivity and specificity of the 2P-1-2-1 antibody for ACCs were both 100%. In other organs studied, positive staining was observed only in the ectopic pancreas. Conclusions It was shown that the 2P-1-2-1 antibody specifically stained the pancreatic acinar cells and tumours of acinar cell origin, such as ACCs. Although it remains unclear at this time to which proteins the monoclonal antibody 2P-1-2-1 is directed, it is suggested to be useful for the pathological diagnosis of ACCs and for the exclusion of other pancreatic tumours.

PD-L1 expression in pancreatic adenosquamous carcinoma: PD-L1 expression is limited to the squamous component

AIM We examined the programmed death-ligand 1 (PD-L1) expression in surgically resected pancreatic adenosquamous carcinoma (PASC) samples. Furthermore, the detection rate was also assessed using biopsy cases obtained from endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). METHODS Fifteen cases of PASC (six resected and nine EUS-FNA biopsied) from the Kurume University Hospital between 2009 and 2016 were used for the evaluation of PD-L1 expression. As a control group, 34 cases of pancreatic ductal adenocarcinomas (PDACs) were selected. To compare　the positivity and intensity of PD-L1, two types of clones (SP263, E1L3N) were examined for immunostaining. Only the membrane expression of PD-L1 was regarded as positive. The PD-L1 expressions in the squamous cell carcinoma component (SCc), adenocarcinoma component (ACc), and immune cells were assessed separately. The ratio of PD-L1 expression was calculated by counting the positive tumor cells, and tumor proportion score (TPS) was applied (TPS; Null < 1%, low expression; 1 ≤ TPS ≤ 49% and high expression; ≥ 50%). RESULTS PD-L1 expression was observed in five surgical PASC samples (83%). This shows that SCc presented a high expression in these cases. However, the overall TPS indicated a low expression. In contrast, only one case (3%) was positive for PD-L1 in PDACs, and the TPS indicated a low expression. No differences in PD-L1 expression were observed between the two clones, SP263 and E1L3N. High PD-L1 expression in the EUS-FNA sample was found in only one case (11%). DISCUSSION Although assessment using the tumor cells of PASC samples obtained from EUS-FNA was difficult, this study suggests the selective expression of PD-L1 in the SCc of PASC. Furthermore, it was considered that immune checkpoint inhibitors could provide therapeutic effects selectively on the SCc for the entire range of TPSs, though the PD-L1 expression was low.