A Rare Case of Atrial Metastasis From a Rectal Adenocarcinoma

Abstract

Colorectal cancers typically metastasize to the lymph nodes, liver or lungs. Metastasis to the heart is rare and although a few cases of cardiac metastases from colon cancer are described in the literature, cases of metastatic rectal cancer to the heart are far fewer. A 69-year-old woman with a history of rectal adenocarcinoma treated with neo-adjuvant chemotherapy and radiation, followed by resection and adjuvant chemotherapy, presented with increasing dyspnea on exertion and lower extremity edema 5 years after oncology follow-up. Echocardiography revealed a mass within the right atrium, which was biopsied and found to be consistent with metastatic rectal adenocarcinoma and a thrombus. The patient was deemed to be a poor surgical candidate given her co-morbidities and overall prognosis. Chemotherapy was offered and refused by the patient. The medical literature has a paucity of similar cases of rectal adenocarcinoma metastasizing to the right atrium. Further studies are needed to help guide standardized treatment options.

Diagnostic and Therapeutic Challenges Associated with the Rare Cardiac Metastasis Complicating Rectal Adenocarcinoma

“…Autopsy studies have revealed that the cardiac metastatic potential was found among the lowest in patients affected by CRC with a prevalence ranging between 1.4 and 2% as opposed to bronchogenic carcinoma that is associated with a 23–31% chance of cardiac metastasis cancer [1, 2]. Although some cases of colon cancer metastasizing to the heart were reported in the literature, very few cases of cardiac metastasis from the rectum [6, 7] as seen in this case were described.…”

“…Cardiac metastases usually involve the right side of the heart [1]. They present diagnostic challenges as their clinical presentation is highly variable and can be confused with primary endocardial tumors, vegatations or organized thrombi [6, 8, 9]. They can be clinically silent or present with nonspecific symptoms including dyspnea and those related to heart failure, arrhythmias and thromboembolism [6, 8, 9].…”

“…They present diagnostic challenges as their clinical presentation is highly variable and can be confused with primary endocardial tumors, vegatations or organized thrombi [6, 8, 9]. They can be clinically silent or present with nonspecific symptoms including dyspnea and those related to heart failure, arrhythmias and thromboembolism [6, 8, 9]. Moreover, the tumor thrombus can extend to the inferior or superior vena cava resulting in obstructive complications [6, 10].…”

“…They can be clinically silent or present with nonspecific symptoms including dyspnea and those related to heart failure, arrhythmias and thromboembolism [6, 8, 9]. Moreover, the tumor thrombus can extend to the inferior or superior vena cava resulting in obstructive complications [6, 10]. Initial evaluation is usually performed using a transthoracic echocardiography which, in most cases, does not differentiate the metastatic lesion from the other possible etiologies [6, 8].…”

“…Moreover, the tumor thrombus can extend to the inferior or superior vena cava resulting in obstructive complications [6, 10]. Initial evaluation is usually performed using a transthoracic echocardiography which, in most cases, does not differentiate the metastatic lesion from the other possible etiologies [6, 8]. Therefore, contrast-enhanced cardiac MRI, which has the advantage of providing more details on the pericardium, myocardial walls and cardiac chambers, is highly recommended for better evaluation of the cardiac mass and reaching to the accurate diagnosis [11, 12].…”