Acute idiopathic interstitial giant cell myocarditis. A histological and immunohistological study of a case

The Authors report on a case of acute idiopathic giant cell myocarditis, which occurred in a young man without previous history of immunodeficiency or tumours, and displayed a rapidly fatal clinical course. Autoptic examination showed diffuse damage to the myocardium, with myocytolysis, granuloma formation and abundant giant cell reaction. No significant changes were observed in the other organs and systems . Immunohistochemistry revealed that the giant cells strongly reacted with the antibody KP1--raised to the macrophage-associated antigen CD68--whereas they did not stain with the monoclonal against the muscle-specific marker desmin. In the light of their findings and previous reports in the literature, the Authors discuss the possible origin of giant cells, along with the pathogenesis of the condition.