An Unusual Cause of Recurrent Respiratory Distress

A one and a half years old boy presented with recurrent episodes of respiratory distress, accompanied by dry non spasmodic cough and characterized by appearance of a continuous stridor showing no positional variation. The child was symptomatic since early infancy. Parents also complained of inability to gain weight as compared to other siblings. There was no history of foreign body ingestion or complaints of asthma or tuberculosis in the family. General physical examination revealed tachypnea and biphasic stridor in a malnourished and stunted child in the absence of any significant lymphadenopathy or oral thrush. On systemic examination, bilaterally, stridorous sounds were auscultated. Primary investigations on the child showed minimal reflux on gastro-esophageal reflux isotope scan, a normal chest roentgenogram, negative sweat chloride test and negative serology for HIV (Human immuno­deficiency virus). Echocardiography performed on the child revealed a structurally normal heart. On conducting further investigations, bronchoscopy detected a bulge in the anterior tracheal wall while barium swallow displayed indentation in the upper esophagus. The MRI (magnetic resonance imaging) subsequently conducted clinched the underlying clinical condition. The MRI images are depicted below.