A rare case of extralobar pulmonary sequestration in geriatric mimicking as organized haemothorax

Dear Editor, Pulmonary sequestration (PS) constitutes a rare group of congenital anomalies that are characterised by an abnormal mass of dysplastic tissue, and supplied by an anomalous systemic artery. It does not have the connection with the trachea-bronchial tree. The incidence of PS is 0.15–6.4%. There are two types of PS: intralobar and extralobar. The extralobar variety is very rare as compared to the intralobar variety (3:1 ratio). The extralobar is generally present at a young age due to its association with other congenital anomalies and is rarely present after the age of 50. We present a very rare case of extra-PS of the right lung in an elderly male who was initially diagnosed as having an organized haemothorax and was referred to our centre for further management. A 71-year-old male, a reformed smoker with no known co-morbidities, presented to a peripheral hospital with a history of a road traffic accident in which he sustained a blunt injury to his right leg. He was evaluated, and his chest radiograph showed a dense homogenous opacity in the right lower zone. He did not give any history of coughing, chest pain, or haemoptysis. He was diagnosed as a case of organized haemothorax and was referred to our centre for further management. He underwent contrast-enhanced computer tomography (CT) of the chest, which showed a large, well-defined soft tissue mass lesion 13.8 × 14.4 × 9.2 cm (antero-posterior (AP)×Medio-lateral (ML)×cranio-caudal (CC)) in the right hemithorax abutting the right hemidiaphragm. The lesion was supplied by a branch from the celiac artery, which was seen ascending into the thorax along with the inferior vena cava (IVC) hiatus through the diaphragm Figure 1A, B. No communication with the bronchial tree was noted. He was diagnosed with extra-PS of the right lung. There were bilateral emphysematous changes. He was managed conservatively and started on inhaler therapy for his obstructive airway disease component. He was offered the choice of lobectomy in view of the increased chances of pulmonary infection, for which he was unwilling. He is presently asymptomatic.Figure 1: (A) Computed tomography of chest showing homogenous opacity in Right lower lobe. (B) 3D reformat with VRT image showing anomalous artery arising from celiac trunk and extending to right hemithorax.Rektorzik initially described PS in 1861 as an abnormal ectopic lung mass with anomalous systemic arterial supply without any identifiable bronchial communication. The incidence ranges around 6% of all congenital pulmonary malformations. The pathogenesis of PS is not clearly understood and includes parapneumonic bud theory, traction theory and vascular development theory. It has been anatomically classified as intralobar pulmonary sequestration (ILS) and as extralobar pulmonary sequestration (ELS). As ILS shares the visceral pleura of the adjacent lung, while extralobar variety has its own visceral pleura.1,2 The development of PS is from the primitive foregut and if the pulmonary bud develops prior to the pleura then it leads to ILS and if the accessory lung bud develops after the formation of the pleura, it leads to a separate pleural layer over the sequestrated lung resulting in ELS. The incidence of PS is generally more common in the left lower lobe (67%). The ILS usually present in adolescence or adulthood as recurrent pneumonia while the presentation of ELS is in fetal and neonatal period and is associated with other congenital anomalies. Our case is extremely rare as our patients had ELS on the right side and in the geriatric age. The ELS variety affects male four times more as compared to females. The age of presentation of ELS is less than 6 months of age and only 10% of cases are asymptomatic.3,4 The computed CT of the chest has an accuracy of diagnosing the PS in 90% of cases, and CT angiography is gold standard for diagnosing this entity as it confirms the anatomy as well as the anamolic blood supply to the lung. Our case is initially diagnosed as organized haemothorax likely in the pretext of RTA but the diagnosis of sequestration is confirmed on CT chest. There are presently no clear guidelines, regarding management of asymptomatic cases of PS. The treatment modality includes resection of the affected part or embolization of the feeding arteries.1,3,4 The patient was offered surgical resection, but he was unwilling for the same. He is presently on out patient department (OPD) follow-up. The diagnosis of extra-PS in this age group is a rare differential but should be considered by the treating physician when managing such cases in the hospital. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.