Mediastinal mass obscured by a large pericardial effusion in a child: a potential cause of serious anaesthetic morbidity.

Anaesthesia in the presence of a mediastinal mass is known to be hazardous. We report a case of a 5-year-old boy with a presumed postviral pericardial effusion presenting for pericardiocentesis under general anaesthesia. Cardiorespiratory collapse following induction of anaesthesia occurred due to an undiagnosed mediastinal tumour. The reasons for misdiagnosis, mechanisms for perioperative complications and optimal management are discussed. Mediastinal masses and underlying malignancy should always be considered in patients with large pericardial effusions.