Metastatic colon cancer involving the right atrium

Abstract

Colorectal cancer rarely metastasizes to the heart. In the world medical literature, we identified only 7 cases of well-documented colorectal cancer metastasis to the right atrium. Herein, we describe the case of a 72-year-old man in whom metastatic mucinous adenocarcinoma of the colon involved the right atrium and caused superior vena cava syndrome. To our knowledge, this is the first case report of sudden cardiac death due to embolization of metastatic colon cancer from the right atrium. We also present the first comprehensive case series review of this rare entity.Given improvements in diagnostic and therapeutic methods that have increased the longevity of many cancer patients, the detection of cardiac metastases is likely to increase in frequency. Accordingly, we recommend that previously asymptomatic cancer patients with a history of colorectal cancer who develop cardiac symptoms undergo prompt investigation for possible cardiac metastasis.

Keywords: Adenocarcinoma, mucinous/secondary; colonic neoplasms/pathology; diagnosis, differential; heart atria/pathology; neoplasms/diagnosis/secondary; superior vena cava syndrome/pathology.

Fig. 1 Transesophageal echocardiography in a patient with superior vena cava syndrome shows A) a mass filling the entire right atrium (RA) and protruding through the tricuspid valve (4-chamber view); B) restricted venous return (arrow) around the RA mass into the right ventricle (RV) (color-flow Doppler), and C) attachment by pedicle (arrowhead) of the RA mass to the RA free wall. LA = left atrium; LV = left ventricle; TV = tricuspid valve

Fig. 2 Photomicrographs (H & E) show A) an infiltrating, moderately to poorly differentiated primary colonic adenocarcinoma, with desmoplastic response in the bowel wall (orig. ×2); and B) a metastatic tumor thrombus in the right atrium, with scattered, preserved tumor cells floating in mucin and fibrin (orig. ×20).