Discussion
Pneumopericardium is rare in adults and is typically described as a result of chest trauma or iatrogenic complication of an invasive procedure (1)(2). It has also been described spontaneously (1) and as a rare complication of pericardiocentesis (3)(4). A recent case series brought light to cancer-related pneumopericadium, and identified 11 reported cases in the literature, 10 of which were in adult males and occurred as a result of a fistulous communication with the esophagus or bronchus (5). To our knowledge, this is the first reported case of pneumopericardium as a result of a fistulous communication with the distal trachea, in this case, manifesting after pericardiocentesis. Fistulous pneumopericardium should be suspected whenever a patient with gastroesophageal or tracheobronchial malignancy presents with chest pain or shortness of breath. Diagnosis can be achieved by chest X-ray showing the appearance of a radiolucent rim around the cardiac shadow, and computed tomography can help demonstrate the presence of a fistulous communication. Treatment depends on the hemodynamic stability of the patient, the presence and location of a fistula, and the overall prognosis and functional status of the patient. Patients with hemodynamic compromise should be treated with pericardiocentesis, while hemodynamically stable patients can be managed conservatively with watchful surveillance for spontaneous absorption of air. If a fistula is present, stenting using endoscopy or bronchoscopy can be pursued to block the fistulous connection and prevent further accumulation of pericardial air. In the presence of an infiltrating malignancy, goals of care should be discussed with the patient and family.