Adult extralobar pulmonary sequestration presenting as a posterior mediastinal mass and hemothorax: a report of two cases

Background Pulmonary sequestration is a rare congenital malformation characterized by dysplastic lung tissue lacking communication with the tracheobronchial tree and receiving systemic arterial supply from aberrant vessels. Extralobar pulmonary sequestration can present along a broad clinical spectrum, ranging from an incidentally discovered posterior mediastinal mass to acute spontaneous hemothorax. Recognizing these contrasting presentations is essential for overcoming diagnostic pitfalls and facilitating prompt management. Case description We report two young adult men with lobar pulmonary sequestration. The first patient, a 28-year-old asymptomatic man, was found to have an abnormal opacity on routine chest radiography. Computed tomography revealed a posterior mediastinal lesion adjacent to the esophagus. Video-assisted thoracoscopic surgery was performed, and the lesion was completely resected. Histopathology confirmed extralobar pulmonary sequestration. The second patient, a 26-year-old man, presented with persistent vomiting, thoracic and abdominal pain, and fever. Computed tomography imaging demonstrated hyperdense pleural effusion suggestive of hemothorax. Emergency video-assisted thoracoscopic surgery evacuated approximately 500 mL of blood and identified a sequestered pulmonary segment with torsion of anomalous systemic feeding vessels causing active bleeding. Complete resection was achieved, and histopathological examination confirmed extralobar pulmonary sequestration complicated by hemorrhagic infarction. Conclusions Pulmonary sequestration should be considered in the differential diagnosis of unexplained thoracic masses and spontaneous hemothorax in young adults. Thoracoscopic resection offers both definitive diagnosis and curative treatment.