Liver histology of acute brucellosis caused by Brucella melitensis

As a major organ of the mononuclear phagocytic system, the liver is probably involved in all cases of brucellosis. In this prospective study, liver slides prepared from percutaneous liver biopsy samples of 20 patients with clinical and laboratory evidence of acute brucellosis due to Brucella melitensis were examined for the presence or absence of granulomas by pathologists in Iran and the United States. Nineteen men and one woman ranging in age from 14 to 62 years were studied. All patients had clinical signs and symptoms compatible with acute brucellosis, and all had significantly elevated titers of antibodies to Brucella in their serum. Liver function tests were mildly elevated in 11 (55%) cases, and C-reactive protein was positive in 15 (65%) patients. Thirteen (65%) patients had blood cultures positive for B melitensis. Iranian and American pathologists reported granulomas in 3 (15%) and in 4 (20%) cases, respectively. There was agreement between Iranian and American pathologists in 17 (85%) cases. The most prevalent findings were mild portal or lobular lymphocytic inflammation (16 cases). Two cases revealed noncaseating epithelioid granulomas, and 2 had microgranulomas. The results show that all patients had microscopic evidence of liver involvement. The predominant histologic finding was mild portal or lobular inflammation with lymphocytes. Granulomas were present in only 4 cases.