Hidden Figures: Occult Intra-Cardiac Metastases in Asymptomatic Neuroendocrine Tumor Patients.

Carcinoid heart disease is a devastating paraneoplastic consequence of unchecked hormone production from neuroendocrine tumors (NET) and often results in right-sided heart failure. While it occurs frequently in NET patients with carcinoid syndrome, cardiac metastases occur much less often and are usually only incidentally found. Gallium-68 dotatate (ga-68) is an imaging tracer which binds to somatostatin receptor 2 with greater avidity than Indium-111, the tracer used commonly in octreotide scans. Ga-68 PET/CT is the most sensitive study for detecting occult NET metastases and has emerged as the current imaging gold standard. We describe two cases from Vanderbilt University Medical Center and Stanford University Medical Center where asymptomatic patients with well-differentiated midgut NET were diagnosed with intra-cardiac metastases using ga-68 PET/CT. Management of these patients was altered based on the findings as they underwent extensive cardiac evaluation and initiation of therapy with octreotide. Fortunately, they have not suffered life-threatening cardiac complications seen in some NET patients, from other published series, such as bradycardia, heart block, syncope and arrhythmias. These possibilities suggest early cardiology evaluation and consideration of other therapies beyond octreotide, such as surgery or PRRT, may be essential for all NET patients found to have intra-cardiac metastases.