Right Ventricular Metastasis From Rectal Cancer Recurrence

BACKGROUND: Cardiac metastases from colorectal cancer are exceedingly rare and pose significant diagnostic challenges, particularly in the absence of disseminated disease. CASE SUMMARY: A 55-year-old man with ulcerative colitis and previously treated rectal adenocarcinoma presented with rising carcinoembryonic antigen levels during surveillance. Colonoscopy excluded local recurrence. Multimodality imaging identified a right ventricular mass, with cardiac magnetic resonance revealing a 36 × 48 mm lesion arising from the right ventricular free wall with endoluminal growth and late enhancement. In the absence of extracardiac disease, intracardiac echocardiography-guided endomyocardial biopsy confirmed metastatic colorectal adenocarcinoma. DISCUSSION: Endomyocardial biopsy remains the gold standard for definitive etiological diagnosis of intracardiac masses and is generally safe when performed in experienced centers. TAKE-HOME MESSAGE: Multimodality imaging and operator expertise are essential for accurate diagnosis of high-risk intracardiac masses.