Right ventricular metastasis in a patient with stage iv small bowel neuroendocrine tumor – a case report

Abstract

Cardiac metastasis from neuroendocrine tumors (NETs) is exceptionally rare and poses diagnostic and therapeutic challenges. We report this case to highlight that cardiac metastases from NETs can be entirely silent yet clinically significant, with early recognition relying on vigilant, multimodal imaging rather than symptom-driven evaluation. We present the case of a 73‑year‑old man who was incidentally found to have a right ventricular mass during lung cancer screening. Imaging studies, including CT, cardiac MRI, and Ga‑68 DOTATATE PET‑CT, revealed a right ventricular apical mass with attachment to the interventricular septum, mesenteric primary tumor, and hepatic metastases. Pathological analysis confirmed a well‑differentiated NET with strong synaptophysin positivity. Despite asymptomatic presentation, he was initiated on octreotide therapy for stage IV disease. Six‑month follow‑up demonstrated stable disease. This case adds to the very limited literature on asymptomatic cardiac metastases from NETs by uniquely demonstrating an incidentally detected right ventricular lesion identified on screening CT rather than targeted cardiac evaluation, with no evidence of carcinoid valvular involvement. In particular, the septal attachment without valvular disease contrasts with most previously reported cardiac NET metastases, which commonly involve valvular structures. Furthermore, this case demonstrates the importance of multimodal imaging in detecting occult cardiac metastasis and highlights the role of somatostatin analogs in managing metastatic NETs. These findings highlight the importance of systematically reviewing cardiac structures during routine imaging to enhance early detection of clinically silent cardiac metastases in NETs.