Right pulmonary lobar agenesis is a very rare anomaly with an incidence of 0.0034%. It is most often diagnosed as an incidentally on an abnormal chest radiograph. It is a congenital defect caused by unsuccessful growth of primitive lung bud. A 5-month-old, female child, with persistent pneumonia was referred to us with cough and respiratory distress. A contrast enhanced CT scan revealed hypoplasia of the right upper lobe of the lung. CT pulmonary angiography showed blind ending of the right upper lobe bronchus with hypoplastic upper lobe pulmonary artery i.e., type 3 pulmonary agenesis. She was treated with ionotropic and oxygen support and an adequate course of antibiotics for pneumonia. This case highlights the significance of a strong suspicion and ample amount of imaging for diagnosis of congenital lung anomalies. Early diagnosis of pulmonary agenesis is vital to lessen the incidence of fibrosis that can occur as a result of recurrent chest infections.
Key words: pulmonary agenesis, lobar hypoplasia, hypoplastic pulmonary artery
Congenital lobar agenesis of lung is caused due to defective growth of primitive lung buds. There are only a handful of cases reported in India. Typically, agenesis of pulmonary lobe is almost always asymptomatic and may remain undiagnosed in the paediatric age group. The incidence of lobar agenesis is 0.0034% with no gender predisposition. There are only two Indian publications till date. A pulmonary computed tomography is regarded as the investigation of choice for diagnosis of lung agenesis. Here we report a rare case of lobar agenesis diagnosed at an earlier than usual age emphasizing the importance of a strong suspicion and ample imaging for the diagnosis of congenital lung anomalies.
A 5month old, female child was referred for further management of unresolving right sided pneumonia after visiting multiple doctors and hospitals. She presented to us with complaints of cough without expectoration and increased respiratory activity over a period of 2 months. There was no history of cardiac involvement. Birth was via normal vaginal delivery with a birth weight of 2.75kgs. Child was immunized for age. There was no developmental delay. On physical examination, the child had tachycardia, tachypnoea with subcostal retractions, bilateral crepitations on auscultation and hepatosplenomegaly. Child was given oxygen by nasal prongs, intravenous antibiotics and inotropic support.
Complete blood count was suggestive of leucocytosis with a positive C- reactive protein. The chest radiograph demonstrated right upper zone opacity with no air bronchogram and pull of trachea towards the right side suggestive of reduced right lung volume with left upper lobar consolidation. Virtual bronchoscopy or a radiologically reconstructed imaging was done to look for an obstruction causing collapse but showed no luminal narrowing or foreign body. A contrast enhanced computed tomography (CT) demonstrated hypoplasia of right upper lobe along with right upper lobe bronchus with hyperinflation of right middle lobe with patchy consolidation in left upper lobe and a small blind ending of right upper lobar bronchus. CT Pulmonary angiography was suggestive of a hypoplastic upper lobe pulmonary artery. She was diagnosed as Type III pulmonary agenesis (hypoplasia).
Fig 1: Chest radiograph
showing right upper zone opacity with no evidence of air bronchogram within
Tests were done for tuberculosis, gastric lavage acid fast bacilli smear and GeneXpert, Mantoux test were negative. Her blood and sputum cultures were negative. Ultrasound of the abdomen was normal. 2D echocardiography was normal. Left sided pneumonia was treated with intravenous antibiotics. Gradually the tachypnoea and distress settled and the child was discharged with advice for strict follow up.