A Rare Case of Atrial Metastasis From a Rectal Adenocarcinoma

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.