Giant-cell myocarditis in a newborn with congenital herpes simplex virus (HSV) infection: an immunohistochemical study on the origin of the giant cells.

Giant-cell myocarditis is a rare inflammatory disorder characterized by degeneration and necrosis of myocardial fibers and presence of chronic inflammatory infiltrates associated with multinucleated giant cells forming a granulomatous inflammatory reaction. The etiology of giant-cell myocarditis is unknown. Many conditions have been reported as associated with this phenomenon such as fungi, virus, sarcoidosis, and hypersensitivity or autoimmune reactions. We are reporting a case of giant-cell myocarditis discovered in a newborn with congenital herpetic sepsis. The myogenic origin of the giant-cells of this case is supported by the positivity for desmin and myoglobin and negativity for muramidase and alpha-1-antichymotrypsin after immunoperoxidase procedure. The presence of Herpes simplex virus type II was confirmed by indirect immunoperoxidase reaction in most of the viscera including the heart, but is not considered a factor in the production of giant cells.