Obstructive coronary ostial thromboemboli mimicking vegetation.

Sudden cardiac death (SCD) in adolescents is rare and often attributed to previously undiagnosed cardiac conditions, including genetic cardiomyopathies, congenital anomalies, conduction disorders, or thrombotic events. In atypical cases, intracardiac or vascular thromboembolism may resemble vegetations, posing a diagnostic challenge during postmortem evaluation. Thorough investigation, including histopathological analysis, is critical to accurately determine the cause of death. We report the case of a 14-year-old girl who experienced acute chest pain and vomiting shortly after school. Although she received immediate emergency care, she collapsed and passed away within hours. She had a history of occasional chest pain, but prior cardiac evaluations had been normal. The autopsy revealed soft, vegetation-like masses blocking both coronary ostia, raising suspicion of several potential underlying conditions. The differential diagnosis includes infective endocarditis, nonbacterial thrombotic endocarditis, thromboembolus formation, cardiac tumors, vasculitis, and iatrogenic causes. There was no evidence of infection or other common predisposing factors for the thromboembolism. The patient had been fasting during Ramadan, raising the possibility of dehydration and increased blood viscosity as contributing factors. This case highlights the potential for coronary thromboembolism to mimic vegetations. Histopathological examination can yield crucial insights that aid in establishing an accurate diagnosis. SCD in adolescents, particularly in the absence of known risk factors, warrants a comprehensive medicolegal autopsy to uncover underlying or contributing pathologies. Accurate differentiation between thromboembolism and vegetations is essential for correct diagnosis, understanding of pathophysiology, and prevention strategies.