Question: Hepatic steatosis is a common finding on liver biopsy. It shows up on ultrasound as increased echogenicity. There are many potential causes of hepatic steatosis. Which of the following is not a cause?
C. hepatitis C
Answer: Alcohol is the classic cause of hepatic steatosis. It is also commonly associated with intracytoplasmic hyaline formation, termed Mallory’s hyaline. Bear in mind that some cases of NASH (related to obesity) also lead to the accumulation of hyaline, and can be difficult to distinguish from alcoholic liver disease.
Wilson disease as well as hepatitis C virus (classically, genotype 3) are known to cause steatosis; in the case of Wilson disease, copper accumulation is present, and in hepatitis C a periportal lymphocytic infiltrate is prominent.
Methotrexate is well known to cause hepatic fibrosis, and steatosis is also possible. Most patients on MTX will show some degree of fibrosis, and the severity is correlated to the total number of grams taken. Regardless of the indication, it is nice to know the baseline liver histology before drug initiation, and liver biopsy should be performed if there is concern for underlying chronic liver disease and pre-existing fibrosis. After starting MTX, serial liver biopsy is indicated as the total number of grams add up, or if the LFT become markedly abnormal. Interferon is not known to cause hepatic steatosis.