Life-threatening haemorrhage due to rupture of pulmonary sequestration arterial supply.

We present a case of a young adult patient with haemoptysis and back pain following 2 days of worsening cough. CT imaging revealed an intralobar pulmonary sequestration of the left lower lobe with an anomalous arterial supply from the thoracic aorta and a large associated haemothorax. The patient developed haemodynamic instability and was taken emergently to the operating room for left thoracotomy. Intraoperatively, active haemorrhage from the aberrant systemic vessel was identified, controlled and ligated. A left lower lobectomy was performed, and the patient made an excellent recovery.Pulmonary sequestration is a rare congenital anomaly of non-functioning lung parenchyma with systemic arterial supply, typically presenting in childhood with recurrent infections. Rarely, as in this case, it presents in adulthood with life-threatening haemorrhage. This case underscores the importance of early recognition and prompt surgical management in adult presentations of pulmonary sequestration with haemorrhagic complications.