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

Abstract

Background: 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.

Case summary: 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.

Discussion: 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.

Keywords: Acute pericarditis; Cardiac tamponade; Cardio-oncology; Case report; Polymicrobial infectious pericarditis; Radiation toxicity.

Figure 1

Electrocardiogram consistent with acute pericarditis. (A) Baseline electrocardiogram prior to radiation therapy showing sinus tachycardia. (B) Electrocardiogram following the third consecutive day of mediastinal radiation therapy showing sinus tachycardia with diffuse ST segment elevations and knuckle sign in lead aVR, consistent with acute pericarditis.

Figure 2

Transthoracic echocardiogram with new moderate pericardial effusion. Baseline pre-radiation therapy (RT) transthoracic echocardiogram without evidence of pericardial effusion: (A) apical four-chamber view, (B) short-axis view, and (C) subcostal view. Transthoracic echocardiogram 6 days after RT showing a new circumferential moderate pericardial effusion with fibrinous strands (arrow). There was no echocardiographic evidence of tamponade: (D) apical four-chamber view, (E) short-axis view, and (F) subcostal view.

Figure 3

Serial CT imaging of mediastinal sarcoma and pericardium. (A) Axial view, CT angiogram of chest showing simple, homogenous pericardial effusion (arrows) and pneumopericardium with pericardial drain in place, 6 days after mediastinal RT. (B) Sagittal view, CT chest demonstrating a 27 × 52 mm posterior mediastinal sarcoma (margins demarcated by lines) exerting mass effect to the left atrium and oesophagus (status post oesophageal stent), 6 days after mediastinal RT. (C) Axial view, repeat CT with contrast showing increased, complex gaseous and heterogeneous pericardial effusion, pericardial thickening (arrows), and pneumopericardium, 21 days after mediastinal RT. (D) Sagittal view, repeat CT chest redemonstrating similar sized sarcoma and thickened pericardium, 21 days after mediastinal RT.

Figure 4

Autopsy and pathology findings from myocardium and pericardium. (A) Gross specimen of the heart and oesophagus demonstrating dense fibrous material over the surface of the anterior aspect of the left ventricle (bottom asterisk), thickened pericardium (left arrow), large oesophageal stent (top asterisk), and oesophagus (right arrow). (B) Gomori trichrome stain of pericardium and myocardium demonstrating myocardium (Layer III), organizing pericarditis with granulation tissue (Layer II), and superimposed acute pericarditis with fibrinous exudate (Layer I). (C) Middle layer of pericardial granulation tissue with fibroblasts and capillaries as well as scattered macrophages; haematoxylin and eosin (H&E) stain. (D) Top layer of the pericardium showing fibrinous exudate with occasional neutrophils (arrow) on H&E stain. Gram stain did not show evidence of bacterial organisms (not shown).