Asymptomatic giant cell hepatitis: a subtype of post-infantile giant cell hepatitis?

Giant cell hepatitis in adults is considered a rapidly progressive and life-threatening disease, but there are few descriptions of a prolonged disease course. A 36-year-old Japanese man was referred to our hospital for further evaluation of abnormal liver function test results. Although asymptomatic, he had undergone follow-up for 9 years with these abnormalities. Because the cause of liver injury was not identified despite extensive noninvasive examinations, the patient underwent needle biopsy. He was finally diagnosed with post-infantile giant cell hepatitis (PIGCH) based on the presence of small numbers of giant multinucleated hepatocytes scattered primarily around the portal area. Necroinflammatory changes were very mild in the portal tracts and hepatic parenchyma. According to the histological findings as well as the accepted international diagnostic scoring system for autoimmune hepatitis (AIH), which is closely related to PIGCH, AIH was unlikely, although antinuclear antibody was positive at a titer of 1:160. The present case may describe an unknown subtype of PIGCH, characterized by insidious disease onset and progression with concurrent, mildly active underlying hepatitis, which is in contrast with the well-documented aggressive nature of PIGCH.