Postinfantile giant cell hepatitis in the setting of autoimmune hepatitis: exclusively a histological pattern or a prognosis predictor?

Autoimmune hepatitis (AIH) is a rare chronic liver disease with a non-specific clinical presentation. Its physiopathology is not fully understood and, if untreated, can progress to cirrhosis and even fulminant liver failure. Here, we describe a case of a 73-year-old patient with an 11-month history suggestive of liver disease, who was concomitantly diagnosed with AIH and the extremely rare postinfantile giant cell hepatitis (PIGCH). Despite standard immunosuppressive therapy, the patient presented a severe clinical course, culminating in acute-on-chronic liver failure and death. This case reminds physicians of the importance of an early diagnosis, close monitoring and timely treatment of AIH. It also highlights the significant role in prognosis of the specific histological pattern of PIGCH, which has been mainly associated with a serious clinical outcome and unpredictable response to immunosuppressive therapy. Triggers of both AIH and PIGCH, such as viral infections, must be excluded, given their treatment implications.