[A case of liver Mycobacterium avium complex syndrome, diagnosed by liver biopsy].

A man in his 70s was referred to our hospital for evaluation of low-grade fever, weight loss, and liver dysfunction. Serological tests for viral hepatitis or autoimmune diseases were negative. No significant findings were observed on whole-body computed tomography (CT). Histopathologic examination of a liver biopsy sample revealed a non-caseating granuloma with acid-fast bacillus using the Ziehl-Neelsen stain. Serum Mycobacterium avium complex (MAC) antibody was positive. We started treatment for pulmonary MAC disease. His clinical condition and liver function improved within two months. He was diagnosed with liver MAC disease.