According to my research, Tylenol long term in doses as low as 3g daily can produce a chronic hepatitis-like picture that mimics liver disease in which Liver Function Tests are typically unremarkable.
Medication effects and other systemic diseases as causes mandate a thorough history).
CND: The Tylenol Toxicity Issue
Acetaminophen And Nsaid Toxicity
Position Statement on Acetaminophen Use and Liver Injury ...
MedlinePlus: Test spots acetaminophen-related liver toxicity