Solitary neuroendocrine carcinoma of the heart

Background: Cardiac tumours are of rare incidence and usually occur in the form of secondary tumours. Most metastatic tumours are melanomas, sarcomas, lung, and haematological malignancies. Neuroendocrine carcinomas (NECs) of the heart are extremely unusual. This case report demonstrates a solitary high-grade NEC of the heart with an individual therapy strategy and follow-up.

Case summary: A 50-year-old gentleman presented with a 2 days history of recurrent episodes of chest pain. Echocardiography, computed tomography, and magnetic resonance imaging revealed tumorous lesions of the ventricles and aortic valve with large circular pericardial effusion. Histopathology results of the biopsy revealed a poorly differentiated small cell tumour of the neuroendocrine type. Despite further investigations with multiple imaging modalities and laboratory, no primary was found. Chemotherapy was initiated but size progression of the tumour was detected. As no other tumorous lesions were detected and resection was not possible because of the tumour complexity, decision on heart transplantation was made. However, due to the necessary immunosuppression after the heart transplantation, multiple metastasis where discovered in the course of treatment.

Discussion: The presence of a NEC in the heart without evidence of any other metastasis or evidence of primary tumour in other organs is clinically unique. For this individual case, heart transplantation was the therapy of choice due to tumour progression under chemotherapy and lacking possibility of resection, as no other suspect lesion was found other than the ones found in the heart. However, the risk of exacerbation of undiscovered micrometastases under necessary immunosuppression following the heart transplantation should be considered.