Polymyositis associated with asymptomatic primary biliary cirrhosis.

We here describe a case of polymyositis associated with asymptomatic primary biliary cirrhosis and a high titer of antimitochondrial antibodies. The patient had remarkable multiorgan engagement: polyarthritis, pericarditis, pleuritis and tachyarrythmia. Atypical changes, suggestive of mitochondrial damage, were observed in a muscle biopsy specimen. Under treatment with azathioprine and steroids, the disease had a favourable outcome.