Extensive Pericardial Metastasis of Angiosarcoma: Diagnostic Challenge in a Young Case With Effusive Constrictive...

A 32-year-old healthy man developed a small pericardial effusion following a motor vehicle accident, which progressed to cardiac tamponade and bilateral pleural effusions over 2 months. Pericardiocentesis drained 1.5 L of hemorrhagic, lymphocyte-predominant exudative fluid, leading to symptomatic improvement and close outpatient follow-up for suspected postcardiac injury syndrome. However, he was readmitted 1.5 months later with recurrent effusions, mediastinal lymphadenopathy, and enlarging hepatic lesions, but without elevated inflammatory markers. Extensive analyses of various fluids, including expert-reviewed cytology and immunostaining, were inconclusive. Despite conservative management, worsening respiratory failure and persistent high chest tube output necessitated venovenous extracorporeal membrane oxygenation. Suspected constrictive pericarditis on transthoracic echocardiography led to the patient's transfer to our quaternary-care hospital for evaluation for pericardiectomy. However, pericardiectomy was deferred due to his unstable respiratory status. Despite intensive care, he eventually died of multiorgan failure 7 months after his initial presentation. Autopsy revealed high-grade hepatic angiosarcoma metastatic to lungs and pericardium with diffuse invasion into the myocardium. This case highlights the importance of cautious interpretation of negative cytology results in patients with recurrent hemorrhagic pericardial effusion, especially without elevated inflammatory markers. When clinical exclusion of pericardial malignancy is challenging, early multidisciplinary consideration of pericardial biopsy may be considered to enhance the diagnostic yield and guide management.