Giant pericardial cyst as the cause of chest pain

A 64-year-old man presented with an 11-day history of chest pain at the left side, without symptoms of cough, sputum, fever, or night sweats. Ten days prior, he was admitted to another hospital. On assessment, the patient had an unremarkable physical examination and routine blood test results; however, his computed tomography (CT) scan showed a left upper lung cavity with a diameter of approximately 4 cm. He was considered to have lung abscess, and after receiving anti-infective treatment with imipenem, his symptoms were slightly relieved. The patient then came to our hospital for further treatment. His-plain chest CT scan revealed a 5.7 × 7.6 cm, thin-walled, cystic light in the left posterior and upper mediastinum. Fluid was observed to be accumulated in the cystic cavity with a visible liquid and air plane, and the lesion was well defined and locally adjacent to the aortic arch and the left side of the spine. An additional contrast-enhanced chest CT scan also revealed homogeneous enhancement of the cyst wall (Fig. 1A,1B). As a result, the initial imaging diagnosis was considered to be fluid and gas inclusions or a pulmonary cyst with concomitant infection. Two days later, the patient underwent single-port thoracoscopic left upper mediastinal cyst resection and received symptomatic treatment, including atomization, expectorant, and anti-infection. Subsequent postoperative histopathology showed a cyst containing dense fibrous tissue, leading to a pathological diagnosis of pericardial cyst with chronic inflammatory cell infiltration (Fig. 1C). Initial symptoms of chest pain resolved postoperatively, and the patient recovered and was discharged from the hospital without complications.