Causes of hepatic granuloma: a 12-year single center experience from southern Iran.

BACKGROUND Hepatic granuloma is reported in 2 - 15% of liver biopsy specimens. It is relatively easy for the pathologist to diagnose, but sometimes arriving at a specific etiology is quite difficult. Until now, there are few published studies about the etiology of hepatic granuloma in Iran. In this study, we attempt to determine the causes of hepatic granuloma from one of the largest referral centers in this country. METHODS In a retrospective study over 12 years, a hepatopathologist reviewed all liver biopsies with granuloma. The medical records, including clinical findings, autoantibodies, viral markers, imaging studies, drug histories, and all other specialized tests, such as molecular studies, were reviewed to reach a definite diagnosis. RESULTS During 12 years, there were 72 cases diagnosed with liver granuloma. The most common cause of hepatic granuloma was infectious, with Mycobacterium tuberculosis (52.8%). The second most common cause was visceral leishmaniasis in 8.3% of biopsies. Other less common causes were fungal infections, visceral larva migrans, primary biliary cirrhosis, and hepatitis C, each in 4.2% of cases. Autoimmune hepatitis was diagnosed in 2.8% of patients. Lymphoma, drug induced, disseminated BCGitis, CMV infection, foreign body reaction and sarcoidosis, were each found in 1.4% of the liver biopsies. After all investigations, there were 12.5% idiopathic hepatic granulomas. CONCLUSION According to this study, the most common cause of hepatic granuloma in Iran is tuberculosis. This finding is completely different from western countries and very similar to the results of countries such as Saudi Arabia.