Acute Torsion of an Extralobar Sequestration: Case Report

Background Pulmonary sequestration is a congenital formation that involves the growth of non-functional lung tissue that is not perfused by the lung arterial blood supply. There are two types of pulmonary sequestrations, intralobar and extralobar. Intralobar sequestrations are more common and usually present in adults as recurrent pneumonia. Extralobar sequestrations are less common, asymptomatic, and usually are found incidentally on prenatal ultrasound. Presentations of symptomatic extralobar sequestrations are very rare and are most commonly diagnosed postoperatively. Case Information: We describe a case of a 6-year-old boy who presented with a three-day history of acute abdominal pain, tachypnea, and a right pleural effusion. A tube thoracostomy was performed to drain his effusion in attempts to improve his symptoms. Computed tomography revealed a right posterior mediastinal mass that was concerning for malignancy. The decision was made to proceed with surgical excision versus biopsy. The patient was found to have a necrotic extralobar sequestration due to torsion. Thoracoscopic resection was performed and the patient was discharged without complication. Conclusions: There are only 10 previously reported pediatric cases of an extralobar sequestration with torsion and only 1 reported on the right side. Extralobar sequestrations appear on imaging as posterior mediastinal masses which elicit a broad range of differential diagnoses in children and are often neoplastic. A review of the pediatric literature demonstrates a common radiographic, pathologic, operative and clinical vignette to maintain a high suspicion of extralobar sequestration for the differential of a paraspinal mass.