Masamichi Kojiro

Pathology of hepatocellular carcinoma in Japan. 232 Consecutive cases autopsied in ten years.

The pathologic findings of 232 consecutive cases of hepatocellular carcinoma (HCC) autopsied during the past ten years at Kurume, Japan, were analyzed from the point of view of global epidemiology, in relation to clinical feature, and in regard to incidence, age, sex, etiologic factors, size of liver, changes in noncancer parenchyma, gross type of tumor, extrahepatic metastases, intravascular and intraductal growths, cancer cell histology, hepatitis B surface antigen (HBsAg) in hepatocytes and cancer cells, liver cell dysplasia, and frequency and clinicopathologic characteristics of minute HCC. Furthermore, postmortem hepatic arteriography and portography were done in 152 livers for comparison with gross anatomy and celiac angiograms. It was found that: (1) epidemiologicall), HCC in Japan is distinct from that in the West that it is frequently encapsulated, livers are generally small because of frequent and advanced cirrhosis and small cancer, minute HCC, is not uncommon at autopsy, cirrhosis most commonly associated is the one with thin stroma and medium size nodules, and micronodular cirrhosis is very rare despite frequent alcohol abuse; (2) HCC is increasing in incidence; (3) HBsAg is frequently found in parenchyma; (4) liver cell dysplasia is indirectly related to HBsAg with no evidence for premalignancy; (5) the lung is the most frequent site of metastasis but peritoneal dissemination is unusual; (6) intraportal tumor growth is very common and the hepatic vein is less frequently affected; (7) growth in the major bile duct is frequently associated with intraportal growth and clinically presents as obstructive jaundice; and (8) tumor is supplied solely by arteries and celiac arteriograms are closely correlated with gross pathologic findings.

Management of Hepatocellular Carcinoma in Japan: Consensus-Based Clinical Practice Guidelines Proposed by the Japan Society of Hepatology (JSH) 2010 Updated Version

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death not only in Japan but also worldwide. Clinical practice guidelines for HCC were first published in 2001 by the European Society of Study of the Liver (EASL) followed by the American Association for the Study of Liver Disease (AASLD) published in 2005 and updated in 2010. However, these guidelines have proven to be somewhat unsuitable for Japanese patients. In 2005, supported by the Japanese Ministry of Health, Labour and Welfare, evidence-based clinical practice guidelines for HCC were compiled in Japan. In 2009, a revised version of evidence-based guidelines was published. Based on both ‘evidence-based’ guidelines and the consensus of an expert panel on HCC, the Japan Society of Hepatology (JSH) published the Consensus-Based Clinical Practice Manual in 2007 and updated in 2010. In this article, the 2010 updated version of this manual, especially issues on prevention, surveillance, pathology, diagnosis, staging, and treatment algorithm are summarized.

Nomenclature of the finer branches of the biliary tree: Canals, ductules, and ductular reactions in human livers

The work of liver stem cell biologists, largely carried out in rodent models, has now started to manifest in human investigations and applications. We can now recognize complex regenerative processes in tissue specimens that had only been suspected for decades, but we also struggle to describe what we see in human tissues in a way that takes into account the findings from the animal investigations, using a language derived from species not, in fact, so much like our own. This international group of liver pathologists and hepatologists, most of whom are actively engaged in both clinical work and scientific research, seeks to arrive at a consensus on nomenclature for normal human livers and human reactive lesions that can facilitate more rapid advancement of our field. (HEPATOLOGY 2004; 39:1739–1745.)

Pathologic diagnosis of early hepatocellular carcinoma : a report of the international consensus group for hepatocellular neoplasia

Advances in imaging techniques and establishment of surveillance protocols for high-risk populations have led to the detection of small hepatic nodules in patients with chronic liver diseases, particularly those with cirrhosis or chronic hepatitis caused by hepatitis B or C viruses. These nodules, comprising a broad range of diagnostic entities—some benign and some with malignant potential—are currently defined histologically, and their clinical management often depends on the ability to make a reliable histologic diagnosis. Evidence accumulated in the last two decades strongly favors the existence of a sequence of events in hepatic nodules that precedes the emergence of hepatocellular carcinoma (HCC),1-10 and these lesions are recognized as precursors of HCC. However, from the beginning of their recognition, there has been considerable confusion concerning nomenclature and diagnostic approaches to these hepatic nodules. To clarify these issues, an International Working Party (IWP) of the World Congresses of Gastroenterology proposed a consensus nomenclature and diagnostic criteria for hepatocellular nodular lesions in 1995.11 The IWP classified nodular lesions found in chronic liver disease into large regenerative nodule, lowgrade dysplastic nodule (L-DN), high-grade dysplastic nodule (H-DN), and HCC; this nomenclature has been widely adopted. In addition, the IWP introduced the concept of dysplastic focus as a cluster of hepatocytes with features of early neoplasia (in particular small cell change or iron-free foci in a siderotic background) measuring less than 0.1 cm, and defined small HCC as a tumor measuring less than 2 cm. More recent studies support the division of small HCC into two clinico-pathological groups that have been termed early HCC and progressed HCC. Early HCC has a vaguely nodular appearance and is well differentiated. Progressed HCC has a distinctly nodular pattern and is mostly moderately differentiated, often with evidence of microvascular invasion.12 Early HCC has a longer time to recurrence and a higher 5-year survival rate compared with progressed HCC.13 Small lesions with malignant potential have only subtle differences from the surrounding parenchyma, making them difficult to assess reproducibly. Differences in the application of diagnostic criteria between Western and Eastern pathologists has been a persistent difficulty in research and clinical management of these lesions.14 In order to obtain a refined and up-to-date international consensus on the histopathologic diagnosis of nodular lesions, such as dysplastic nodules and early HCC, the International Consensus Group for Hepatocellular Neoplasia (ICGHN) was convened in April 2002 in Kurume, Japan. The group has met several times up to July 2007 under the auspices of the Laennec Liver Pathology Society. The ICGHN is currently comprised of 34 pathologists and two clinicians from 13 countries. It includes most members of the original IWP who are still active and all the participants from the first ICGHN meeting. This consensus document summarizes the results of our meetings.

Reevaluation of prognostic factors for survival after liver resection in patients with hepatocellular carcinoma in a Japanese nationwide survey

Advances in the diagnosis and surgical treatment of hepatocellular carcinoma (HCC) have improved the prognosis for patients with HCC who undergo liver resection. The objective of this study was to evaluate prognostic predictors for patients with HCC who underwent liver resection in a Japanese nationwide data base.

Pathology of Hepatocellular Carcinoma

The discovery of alpha-fetoprotein and hepatitis B virus related antigens, and the development of diagnostic techniques in the past decade brought a new epoch in the study of hepatocellular carcinoma (HCC). Therefore, pathology of HCC should be re-investigated in accordance with the development of clinical aspects. In this paper, we have described the pathology of HCC based on both autopsy and surgical materials with special reference to angioarchitecture, unusual tumor growth, and histological growth pattern of HCC. Primary tumor, tumor thrombi in the portal vein and the hepatic vein, and intrahepatic metastasis receive arterial blood supply through arterial tumor vessels deriving from the hepatic artery. Unusual tumor growths, such as intrabile duct and intra-atrial tumor growths, have become relatively common, and tumor casts in the bile duct and the right atrium also receive arterial blood supply through arterial tumor vessels. histological growth pattern of HCC can be classified into three types; sinusoidal type, replacing type, and pseudoencapsulated type. The frequency of remote metastasis is different in each type.

Report of the 17th Nationwide Follow-up Survey of Primary Liver Cancer in Japan.

In the 17th Nationwide Follow‐up Survey of Primary Liver Cancer in Japan, 18 213 individuals were newly registered as patients with primary liver cancer at 645 medical institutions over a period of 2 years (from 1 January 2002 to 31 December 2003). Of these patients, 94.2% had hepatocellular carcinoma (HCC) and 4.1% had intrahepatic cholangiocarcinoma (ICC). In addition, 24 705 follow‐up patients were registered in the survey. Epidemiological and clinicopathological factors, diagnosis and treatment were investigated in the newly registered patients, and the cumulative survival rates of newly registered patients in the 12th to 17th follow‐up surveys conducted between 1992 and 2003 were calculated for each histological type (HCC, ICC, and combined HCC and ICC) and stratified by background factors and treatment. The data obtained in this follow‐up survey should contribute to future research and medical practice for primary liver cancer.

Predictive factors for long term prognosis after partial hepatectomy for patients with hepatocellular carcinoma in Japan. The liver cancer study group of japan

Background. Great progress in the diagnosis and surgical treatment of hepatocellular carcinoma (HCC) has led to an increased number of resectable cases. Much attention has been paid to the factors affecting long term survival of patients with HCC after partial hepatectomy.

Clinical aspects of intrahepatic bile duct carcinoma including hilar carcinoma. A study of 57 autopsy‐proven cases

The clinical features of 57 autopsied cases of intrahepatic bile duct carcinoma including 28 cases of the peripheral type (cholangiocarcinoma in the narrow sense) and 29 cases of the hilar type are described in comparison with those of hepatocellular carcinoma, with a review of the literature on the clinicopathological aspects of intrahepatic bile duct carcinoma. As compared with hepatocellular carcinoma, the average age of the patients was older; the male predominance was not obvious, chronic parenchymal liver disease was infrequent in the past history, association of primary cirrhosis was seldom, cholestatic features were frequently the early signs and more pronounced during the course, the liver was enlarged to a lesser extent, ascites was less common, signs of portal hypertension were absent or minimal, and extrahepatic metastases were less frequent. In many respects, the hilar type resembled extra‐hepatic bile duct carcinoma, and the peripheral type was somewhat between it and hepatocellular carcinoma. Although the overall survival was not much different from that for hepatocellular carcinoma, early diagnosis is emphasized; this would make surgical management possible. Differential diagnosis from hepatocellular carcinoma may be possible in the majority with direct cholangiography, liver scan, celiac angiography, determination of α‐fetoprotein and hepatitis B antigen, and blood chemistry such as SGOT, SLDH, serum bilirubin and alkaline phosphatase. Illustrative cases are given including one patient with a hilar carcinoma who survived for more than 2 years after transhepatic biliary drainage.

Comparison of the outcomes between an anatomical subsegmentectomy and a non-anatomical minor hepatectomy for single hepatocellular carcinomas based on a Japanese nationwide survey.

BACKGROUND Although a surgical resection is an important modality for the treatment of hepatocellular carcinoma (HCC), the impact of the operative method on both the patient survival and disease-free survival (DFS) still remains controversial. METHODS Using a nationwide Japanese database, 72,744 patients with HCC who underwent a curative liver resection between 1994 and 2001 were divided into two groups based on whether an anatomical subsegmentectomy (AS) or a non-anatomical minor hepatectomy (MH) was performed. A total of 5,781 patients with single HCCs were selected for the study and divided into 3 subgroups based on the size of the HCCs (less than 2 cm, 2 to 5 cm, and greater than 5 cm in diameter). An AS was performed for 2,267 patients while an MH was performed for 3,514 patients. RESULTS The overall DFS was significantly better after an AS (P = .0089). When the patients were stratified according to the size of the HCC, a better DFS was seen in the patients with HCC from 2 to 5 cm after an AS (P < .0005). Further stratification according to liver damage did not show any significant differences between an AS and an MH. CONCLUSION An AS is therefore recommended, especially when the size of HCC ranges from 2 to 5 cm.