LAUSR

© BMJ Publishing Group Limited 2021. No commercial reuse. See rights and permissions. Published by BMJ. DESCRIPTION A 70yearold woman who had been taking oral steroids with tapering after an acute exacerbation of idiopathic pulmonary fibrosis (IPF) was diagnosed with stage IIIB squamous cell lung cancer by transbronchial lung biopsy from left hilum 6 months before admission. At the time, she had anorexia due to the psychological impact of a cancer diagnosis, so she declined chemotherapy. Subsequently, her symptoms improved with pharmacotherapy, so tegafur/gimeracil/oteracil was started. Thirtysix days after starting chemotherapy, she presented to the outpatient clinic to assess the lung cancer by chest CT; she had a 5day history of chest pain, exacerbation of cough and severe palpitations. Chest CT revealed known lung cancer on the left hilum, abutting the pericardium, which had invaded the mediastinum, causing pneumopericardium and pneumomediastinum (figure 1). Her blood pressure was 120/67 mm Hg, and heart rate was 88 bpm. On physical examination, jugular vein distention (JVD) in the sitting position and muffled heart sounds were observed. Echocardiography showed no reduction in ejection fraction, although the pneumopericardium prevented detailed observation. Fluoroscopyguided urgent pericardiocentesis was performed through the superior margin of the left fifth rib, and the air was aspirated. Subsequently, JVD, dyspnoea and chest pain were improved. The patient was followed up with CT the next day and the fourth day after admission. She was discharged on the fifth day since the pneumopericardium was shrinking and most of the air had been absorbed (figure 2). Although the patient died 6 months after discharge due to the progression of lung cancer, there was no recurrence of pneumopericardium. Pneumopericardium is a rare condition, and the causes have been reported to include trauma, fistula formation between the pericardium and adjacent aircontaining structures, barotrauma, pericardial infections and iatrogenic trauma. In this case, pneumopericardium was caused by lung cancer in contact with the pericardium. In addition, the patient had cough and tissue fragility of the peribronchial sheats due to IPF. The patient was also taking oral steroids, which are known to cause delayed wound healing and are a risk factor for pneumothorax and pneumomediastinum. The combination of factors such as tissue fragility due to IPF and delayed wound healing due to steroids, in addition to lung cancer, may have promoted the development of pneumopericardium and pneumomediastinum. Conservative treatment is the treatment of choice in patients with haemodynamic stability. However, pericardiocentesis, pericardial window procedure or drainage of the pericardial sac are the recommended optimal treatments in patients with cardiac tamponade. 4 Initially, physical findings and symptoms were suspected to have progressed to cardiac tamponade. However, there was no decline in her blood pressure, so we first performed a pericardiocentesis to see if her symptoms would disappear. After that, close monitoring and CT were performed to followup and monitor improvement of the pneumopericardium. In some cases, cardiac tamponade caused by pneumopericardium has led to cardiac arrest. Therefore, in addition to careful monitoring of haemodynamics when pneumopericardium is diagnosed, it is desirable to intervene Figure 1 Coronal reconstruction of the chest CT scan shows squamous cell lung cancer (arrow) on the left hilum (arrowhead) that invades the mediastinum. Axial section of the chest CT scan shows IPF, pneumomediastinum (asterisk) and pneumopericardium with an anterior extent (arrowhead). IPF, idiopathic pulmonary fibrosis.