Acute radiation-induced pericarditis complicated by polymicrobial infectious pericarditis in a patient with mediastinal sarcoma: a case report

Acute pericarditis is often caused by viral infections, autoimmune diseases, and radiation therapy (RT). Infectious pericarditis is rare and associated with high morbidity and mortality. We present a case of acute RT-induced pericarditis complicated by bacterial pericarditis and cardiac tamponade due to oesophageal bacterial translocation.

A 65-year-old man with a recurrent mediastinal sarcoma complicated by oesophageal compression and recent oesophageal stenting presented with shortness of breath. Electrocardiogram showed diffuse ST elevations, and he was diagnosed with presumed RT-induced pericarditis. Despite anti-inflammatory therapy, he developed haemodynamic instability and clinical tamponade, with transthoracic echocardiogram showing a large circumferential pericardial effusion. He underwent emergent pericardiocentesis, and pericardial fluid cultures grew polymicrobial species. Anti-inflammatories were held, and he was started on broad spectrum intravenous antibiotics and antifungals. Due to clinical decompensation and repeat computed tomography imaging demonstrating worsening pericardial disease, he underwent pericardial irrigation and subxiphoid pericardial window. The patient died from hypoxaemic and hypercapnic respiratory failure. Autopsy revealed constrictive pericarditis and no bacterial organisms in the pericardium.

Anti-inflammatories are standard treatment for viral and RT-induced pericarditis. Purulent, bacterial pericarditis is rare and an uncommon complication of RT-induced pericarditis. Polymicrobial infectious pericarditis is often refractory to intravenous antibiotics, requiring surgical intervention. This case highlights the importance of maintaining a high index of suspicion of various potential aetiologies of pericarditis in order to tailor medical and surgical therapies especially in high-risk, immunosuppressed cancer patients.