Nonrheumatoid Fibrinous Pericarditis A Medical Examiner Algorithm for the Diagnosis of Viral Myocarditis and Use of Molecular Diagnostic Techniques

摘要

Classic "bread-and-butter" appearance of fibrinous pericarditis had been described in rheumatic disease and other immunologic diseases such as systemic lupus erythematosus, post-myocardial infarct, uremia, tuberculosis, radiation effects, bacterial, and viral etiology. In most of the described cases, pericarditis occurs as a delayed complication. We present a case of a 21-year-old white woman who was seen in the emergency department to rule out pulmonary embolism for shortness of breath, chest pain, and lightheadedness. The autopsy showed a collection of serous fluid into the pericardial sac with bread-and-butter appearance. Microscopically, the pericardium showed acute inflammation with fibrinous exudates. Sections of the heart showed areas of lymphocytic infiltration with acute fibrinous inflammation of the pericardium. Vasculitis was seen in small blood vessels in the heart and was negative in other organs. No granuloma or necrotizing lesion was seen in microscopic sections of all organs including the heart, ruling out rheumatologic disease. The present study highlights the quest and design of an algorithm for a nonrheumatic disorder as the cause of pericarditis. Molecular studies were performed on heart tissue blocks for identification of cardiotropic viruses. Human parvovirus B19 was isolated from heart tissue blocks. The present case study highlights on updates in pathophysiology and diagnostic criteria for myocarditis along with the use of new molecular techniques for detection of idiopathic cardiomyopathies in a medical examiner setup.