S1707 Heart to Believe: Right Atrial Mass and New Onset Heart Failure Due to Metastatic Colon Adenocarcinoma

Abstract

INTRODUCTION: A 58 year old male with history of early stage colon cancer diagnosed six years ago status post right hemi-colectomy without chemotherapy and apparently in remission presented with symptoms of heart failure and found to have a right atrial mass. CASE DESCRIPTION/METHODS: On admission, labs with mildly elevated liver enzymes. A transthoracic echo showed a pedunculated right atrial mass. Cardiac CT with contrast confirmed the presence of an 8 cm × 6 cm right atrial mass with extension into the hepatic vein and inferior vena cava. (Figure A, arrows). Biopsy of mass showed moderately differentiated colonic adenocarcinoma with cribriform glandular growth pattern (Figure B) staining positive for CDX1 and cytokeratin 20 (Figure C, D respectively), and negative for cytokeratin 7 (Figure E). Recent abdominal surveillance CT scans did not show any evidence of recurrent disease and tumor markers were normal. Subsequent colonoscopy showed a healthy appearing anastomosis without evidence primary colon tumor recurrence (Figure F). DISCUSSION: While colon cancer is the third most common cause of cancer in the United States, known metastasis to the cardia is extremely rare. To our knowledge there are only ten such cases, with all of them affecting the right atrium or ventricle.1–2 Given the clinically silent nature of metastatic cardiac malignancies, many are undiagnosed until autopsy, which estimates the presence of such metastasis ranging 2–7%.3 Spread is typically hematogenous given the intra-cardiac location of these tumors. Treatment is palliative FOLFOX based chemotherapy, although emergent surgical resection is considered in cases of hemodynamic compromise. Overall prognosis is poor with 5-year survival rates of 10-14%2.Although metastatic cardiac disease is rare, our case illustrates the need for an extensive diagnostic workup in any patient with a history of colorectal cancer presenting with new onset heart failure symptoms.Figure 1.: Figure A: Cardiac CT illustrating right atrial tumor (Arrows).Figure 2.: Figure B-E: Pathology images showing adenocarcinoma staining positive for CDX1/Cytokeratin 20 and negative for Cytokeratin 7.Figure 3.: Figure F: Colonoscopy with healthy appearing anastomosis.