A rare case of fatal lymphocytic myocarditis in a young female: an autopsy report

Abstract

Lymphocytic myocarditis (LM) is an inflammatory disease of the heart muscle most frequently associated with viral infections and autoimmune disorders. It is a rare but potentially lethal cause of sudden cardiac arrest, particularly in young individuals. We present an uncommon case of fulminant LM in a 13‑year‑old female who experienced fever, tiredness, malaise, and vomiting for two days prior to death. She was initially treated with paracetamol and intravenous fluids but soon deteriorated, developing severe dyspnoea and abdominal pain before being declared dead upon arrival at our hospital. The autopsy revealed frothy secretions within the airways, marked pulmonary congestion and haemorrhages, as well as pericardial effusion accompanied by variable degrees of epicardial and myocardial inflammation. Histopathological examination demonstrated significant cardiac inflammation with dense lymphocytic infiltration, confirming LM as the cause of death. This case illustrates the rapid and severe progression of fulminant myocarditis, leading to abrupt clinical deterioration and sudden death. Despite initial symptomatic management, the patient expired within 48 hours of symptom onset. This report underscores the importance of early recognition of myocarditis in young patients presenting with flu‑like symptoms, unexplained hypotension, and worsening dyspnoea. Heightened clinical vigilance and timely intervention may improve outcomes in such cases. Furthermore, myocarditis should be considered in the differential diagnosis of sudden unexplained deaths, particularly in young individuals with nonspecific prodromal symptoms.