Sepsis-related microvascular myocardial damage with giant cell inflammation and calcification.

We report a case of a 27-year-old man who died suddenly 2 days after being discharged from the intensive care unit where he had resided for 25 days due to severe sepsis. On postmortem examination, the findings were restricted to the heart and characterized by microvascular myocardial damage with giant cell inflammation and calcification. The microcirculation seems to be involved in the mechanism of cell injury, very likely due to flow disturbances caused by septic shock. The dystrophic calcification occurred in myocytes showing myocytolysis. Lysozyme produced by macrophages and myocytes in areas of myocytolysis and giant cells appear to function cooperatively and/or synergistically to influence mineralization. In addition, the expression of inducible nitric oxide synthase by myocytes implies that nitric oxide could contribute to myocardial cell damage. Immunolabeling studies of the giant cells confirmed that they are derived from macrophages.