Encased in Peril

   This NEJM case details a 75-year-old man with atrial tachyarrhythmias, tricuspid regurgitation, and pericarditis who developed progressive dyspnea, leg edema, and abdominal bloating following catheter ablation. Initial workup revealed pericardial effusion with tamponade, elevated inflammatory markers, and echocardiographic signs of constrictive physiology, including septal bounce and hepatic vein expiratory flow reversal. Despite transient relief post-pericardiocentesis and anti-inflammatory therapy with colchicine and anakinra, cardiogenic shock ensued. Imaging suggested pericardial thickening, adhesions, and loculated effusions. Emergency surgery uncovered a thick, unresectable pericardial mass encasing the heart and aorta. Autopsy confirmed primary pericardial mesothelioma—an exceptionally rare malignancy, often undetected on cytologic fluid analysis and imaging. The case underscores challenges in diagnosing effusive-constrictive pericarditis and differentiating inflammation from malignancy, with lessons on multimodality assessment, clinical vigilance, and the poor prognosis of unresectable pericardial tumors.

   This NEJM case details a 75-year-old man with atrial tachyarrhythmias, tricuspid regurgitation, and pericarditis who developed progressive dyspnea, leg edema, and abdominal bloating following catheter ablation. Initial workup revealed pericardial effusion with tamponade, elevated inflammatory markers, and echocardiographic signs of constrictive physiology, including septal bounce and hepatic vein expiratory flow reversal. Despite transient relief post-pericardiocentesis and anti-inflammatory therapy with colchicine and anakinra, cardiogenic shock ensued. Imaging suggested pericardial thickening, adhesions, and loculated effusions. Emergency surgery uncovered a thick, unresectable pericardial mass encasing the heart and aorta. Autopsy confirmed primary pericardial mesothelioma—an exceptionally rare malignancy, often undetected on cytologic fluid analysis and imaging. The case underscores challenges in diagnosing effusive-constrictive pericarditis and differentiating inflammation from malignancy, with lessons on multimodality assessment, clinical vigilance, and the poor prognosis of unresectable pericardial tumors.