Cardiac hamartomas: report of two rare primary cardiac tumors (rhabdomyoma and hamartoma of mature cardiomyocytes) with review of the literature

Abstract

The most common primary cardiac tumors are myxomas, while cardiac hamartomas are rare. Cardiac hamartomas may constitute manifestation of a genetic disorder such as tuberous sclerosis, or could be diagnosed independently as a solitary lesion. We present two rare cases of primary cardiac tumors detected via diagnostic imaging and subsequent histopathology examination. The fi rst described case is that of a male preterm foetus with multiple rhabdomyomas in the heart, discovered during foetal echocardiography. The finding was later confi rmed by autopsy, which also revealed presence of cortical tubers with typical balloon cells constituting well known epileptogenic lesions in the foetal brain. 
The second case describes an even rarer benign cardiac lesion – a hamartoma of mature cardiomyocytes – which was discovered by chance in a 49-year old female patient during echocardiography. The performed CT scan revealed a 37 x 16 x 12 mm tumor in the right atrium obstructing the superior vena cava inlet. The malformation was surgically removed and examined histologically revealing disorganized hypertrophic mature cardiomyocytes, partly separated by fi brous strands and admixed with mature adipocytes. Diff erential diagnosis was performed to rule out other benign tumors with myocyte diff erentiation – cardiac rhabdomyoma, histiocytoid cardiomyopathy and adult cellular rhabdomyoma. 
Conclusion: The diagnosis of cardiac hamartomas was possible only after pathomorphological examination of material from the tumors. Reporting of rare neoplasms is crucial in order to determine their prevalence and to inform clinical practice.