Conduction System Hamartoma: Autopsy Case Series.

Abstract: Conduction system hamartoma is a benign hamartomatous lesion arising from Purkinje and Purkinje-like cells of the heart. We aimed to investigate the cases that we detected during postmortem histopathological examination. The histopathology reports of the cases autopsied between 2012 and 2022 were reviewed retrospectively. The cases were evaluated in terms of histopathological features, demographic data, autopsy findings, causes of death, microbiological results, and accompanying cardiac anomalies. There was a total of 4 cases. The female-to-male ratio was 3/1. The mean age of the cases was 5.8 months. The heart weight was found within the normal range when evaluated according to age and gender. Microscopy revealed sharply demarcated cell groups or layers with histiocyte-like cells with foamy cytoplasm. Congenital heart disease and lung infection were given as causes of death in all cases. The lesion, which was previously called histiocytoid cardiomyopathy and many different names, is known as "conduction system hamartoma" in the latest World Health Organization classification (5th edition). Being aware of this entity that causes fatal arrhythmias and sudden cardiac deaths is important for pathologists. Autopsy findings should be evaluated by taking extra samples from the heart if necessary, especially in suspected cases below 2 years of age.