Right Ventricular Outflow Obstruction Due to Metastatic Neuroendocrine Tumor.

Neuroendocrine tumors (NETs) are rare malignant tumors that arise from neuroendocrine cells of the gastrointestinal tract and often metastasize to the liver, lung, and bone. Cardiac metastasis of NETs is uncommon. We report a patient with a past medical history of a neuroendocrine tumor of the left femur presenting with signs and symptoms of new onset heart failure. Transthoracic echocardiogram and cardiac magnetic resonance showed a large mass within the right ventricle causing right ventricular outflow obstruction. A positron emission tomographic/computed tomographic scan (PET-CT) revealed increased uptake of fluorodeoxyglucose (FDG) activity within the right ventricle consistent with metastasis. Cardiac biopsy of the right ventricular mass revealed metastatic nonfunctioning neuroendocrine tumor. In view of the fact that it was a tumor that caused the right ventricular obstruction, the patient was started on chemotherapy with improvement of symptoms. This case highlights that in patients with a history of neuroendocrine tumor presenting with heart failure, cardiac metastasis should be included in the differential.