| Theme |
Nonalcoholic Steatohepatitis (NASH) |
| Title |
Histopathology of NASH |
| 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). |