Metastatic Midgut Carcinoid to the Heart Demonstrated on Cardiac Magnetic Resonance Imaging

Abstract

A 53-year-old man presented with vague abdominal cramps, pain, diarrhea, and increasing weight loss. He underwent colonoscopy and an abdominal computed tomography scan that demonstrated a mass in the cecum and liver lesions. At laparotomy, peritoneal seeding and liver metastases were found. The pathology revealed a well-differentiated neuroendocrine carcinoma (NET) arising from multiple small bowel tumors.On assessment in a multidisciplinary NET clinic, he had a classic type 3 carcinoid flush. There was a loud 3/6 holosystolic murmur at the lower left sternal border, increasing with inspiration. He had an elevated u5-hydroxyindoleacetic acid, 118 mol/L (normal Ͻ41) and an elevated chromogranin A 290 ng/mL (normal, 6 -39). A magnetic resonance imaging (MRI) scan of abdomen demonstrated multiple hypervascular liver lesions and retroperitoneal lymph node enlargement. Both his metaiodo-benzylguanidine and octreotide scans ( Fig. 1) confirmed multiple liver lesions, a lesion in the left anterior chest lesion. An echocardiogram demonstrated a cardiac mass arising from the right side of the ventricular septum that did not interfere with ventricular flow and moderate tricuspid regurgitation consistent with carcinoid heart disease. A cardiac MRI scan (Fig. 2) demonstrating a 4.1 ϫ 4.1 cm mass arising from the interventricular septum and protruding into the right ventricle.Patient was placed on both short-acting and long-acting (LAR) somatostatin analogue. He underwent 3 cycles of I 131 metaiodo-benzylguanidine therapy (4443 MGq each cycle), before reassessment. Eighteen months after his presentation, he is symptomatically controlled on 30 mg of LAR, and his cardiac examination is unchanged.To our knowledge, this is the second reported case of carcinoid metastases to the heart seen on cardiac MRI imaging. 1 In contrast to the Puvaneneswary et al case, this metastasis is myocardial in origin and not arising from the pericardium. Metastatic tumors to the heart are relatively uncommon and are usually associated with carcinomas of the lung, breast, and melanomas. Since 1985 when the first report of myocardial metastases from NET was reported, there have only been 26 reported cases in the literature. 2 Pandya et al reported 11 patients with myocardial metastases, in which the right ventricle was involved in 40%, the left ventricle in 53%, and the ventricular septum in 7%. 3

A primary neuroendocrine tumor of the left ventricle presenting with diarrhea—an unusual experience and literature review

“…A high index of suspicion for metastatic disease in cardiac neuroendocrine tumor should prompt further investigations for identifying occult primary tumors. The most common primary sites of these tumors are the gastrointestinal tract, lungs, and mediastinum, followed by the skin (Merkel cell carcinoma) [16][17][18][19].…”