Case 1, image 1: This was a 27 year old man who died of acute lymphocytic myocarditis. He had been complaining of chest tightness several months prior to death. There is a lymphocytic infiltration and granulation tissue within sections of the left ventricle.
Case 1, image 2: Myocyte necrosis accompanies the inflammatory infiltrate.
Case 1, image 3: Trichrome staining highlights areas of fibrosis, indicating that this was process had been going on for some time.
Case 1, image 4: Another Trichrome image demonstrating an area of scar formation.
Case 2, image 1: This 14-year-old boy died of myocarditis. He was witnessed to suddenly collapse while hiking. He had been complaining of headaches for several days prior to his death, which had seemed to resolve with over the counter medications.
Case 2, image 2: There was prominent chronic inflammatory infiltrate within all three layers of the heart with associated myonecrosis.
Symptoms of myocarditis can range from minimal chest discomfort to shock and death. There are many causes of myocarditis including viral infections (i.e. coxsackievirus B, adenovirus), bacterial infections (streptococcus, staphylococcus) and less commonly, fungal infections and parasites. Exposure to certain drugs and systemic illnesses (i.e. lupus, connective tissue disorders, Wegener's granulomatosis) may also cause myocarditis.
Myocarditis can present as sudden death in children. The heart may appear normal grossly and thus, adequate histologic sampling that includes the conduction system is critical.