Cardiac Metastasis Caused Fatal Ventricular Arrhythmia in a Patient with a Rectal Neuroendocrine Tumor

Abstract

A 60-year-old man had received octreotide for a metastatic neuroendocrine tumor (NET) in the rectum. Computed tomography and ultrasonography revealed a cardiac tumor, diffuse thickness of the ventricular wall and pericardial effusion, which was diagnosed as cardiac metastasis. The metastatic lesions continued to grow despite the alteration of chemotherapy, and the patient complained of repeated syncope and was admitted to our hospital at 11 months after the diagnosis of cardiac metastasis. An electrocardiogram during syncope showed sustained ventricular tachycardia, which was considered to be caused by the cardiac metastasis. We herein report a case of NET with cardiac metastasis which caused lethal arrhythmia along with a review of the pertinent literature.

Keywords: cardiac metastasis; neuroendocrine tumor; ventricular arrhythmia.

Figure 1.

CT findings at the initial diagnosis of NET. Computed tomography at the initial diagnosis showed swelling of multiple lymph nodes (A: arrowheads) without the detection of the primary lesion and liver metastasis (B: arrowhead), consolidation of the vertebra and iliac bone (C), and findings of a tumor and an abnormal enhancement in the left ventricle and septum (D).

Figure 2.

Endoscopic, histological and immunohistochemical findings at the initial diagnosis of the rectal tumor. Colonoscopy revealed a yellowish submucosal tumor measuring 25 mm in diameter, accompanied by dilated vessels at the surface and depression in the central part (A). Histological findings of the biopsied specimen (Hematoxylin and Eosin staining; B ×100) showed a rope-shaped or ribbon-like arrangement of cells with elliptic nuclei and eosinophilic cytoplasm, and the immunohistochemical findings were positive for CD56 (C ×100) and synaptophysin (D ×100), with about 10% of cells positively reactive for MIB-1 (E ×100), consistent with NET grade 2 according to the WHO classification 2010.

Figure 3.

CT and TTE findings in the heart at the time of the detection of cardiac metastases. Contrast-enhanced CT revealed a tumor with a poor enhancement in the ventricular septum (A; arrowhead) and heterogenous wall thickening of the left ventricle (B; arrowheads) along with pericardial effusion (A, B). TTE showed that the mass originated from the ventricular septum and protruded into the right ventricle lumen on a parasternal long-axis tomogram (C; arrowhead), and diffuse wall thickening of the left and right ventricle was noted on an apical 4-chamber tomogram (D; arrowheads).

Figure 4.

Electrocardiogram recorded at syncope. An electrocardiogram recorded at syncope showed ventricular tachycardia.

Figure 5.

CT and TTE findings in the heart when complicated with ventricular arrhythmia. The progression of the tumor and wall thickening with the poor enhancement in the ventricular septum and wall are observed on CT (A; arrowheads), and the progression of the protruding mass in the ventricular septum (B; arrowhead) and exacerbation of diffuse thickening of the ventricular wall were detected with TTE (B; arrows).