Clinical Gastroenterology Vol.18 No.9(3)

Theme Nonalcoholic Steatohepatitis (NASH)
Title Histopathology of NASH
Publish Date 2003/08
Author Hideaki Enzan Department of Pathology, Program of Bioregulation and Genetics, Kochi Medical School
Author Shuji Kawai Department of Pathology, Program of Bioregulation and Genetics, Kochi Medical School
Author Makoto Toi Department of Pathology, Program of Bioregulation and Genetics, Kochi Medical School
Author Naoto Kuroda Department of Pathology, Program of Bioregulation and Genetics, Kochi Medical School
Author Makoto Hiroi Department of Pathology, Program of Bioregulation and Genetics, Kochi Medical School
Author Toshiji Saibara Department of Gastroenterology and Hepatology, Program of Bioregulation and Genetics, Kochi Medical School
[ Summary ] Nonalcoholic steatohepatitis (NASH) is a chronic liver disease and may occasionally progress to fibrosis or cirrhosis. Histopathological findings related to NASH are associated with steatosis-related findings (macrovesicular steatosis, lipogranuloma, and glycogenated nucleus), hepatitis-associated findings (hepatocellular ballooning degeneration, occurrence of Mallory's hyaline, acidophilic bodies, iron deposition in zone 1 hepatocytes, activation of Kupffer cells and hepatic stellate cells, and also lobular and portal inflammatory cell infiltration), and varying degrees of fibrosis (predominantly zone 3 perivenular and perisinusoidal/pericellular fibrosis). Since the histopathologic criteria for diagnosis are not specific and no single pathognomonic finding is present in NASH, a combination of findings, such as macrovesicular steatosis, hepatocellular ballooning and mixed mild intralobular inflammation, are necessary for this diagnosis. In NASH with progression to liver cirrhosis and a poor prognosis, biopsies may show hepatocellular ballooning, Mallory's bodies and/or fibrosis. In fibrosis staging, NASH can be categorized into five stages; from NASH with no fibrosis (stage 0) and with zone 3 fibrosis (stage 1), through the stages with more progressive fibrosis, including periportal (stage 2) and bridging fibrosis (stage 3) to liver cirrhosis (stage 4).
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