A 12 year old boy is referred for preanesthetic evaluation prior to adenoidectomy and bilateral grommet insertion for otitis media with effusion. He has had recurrent history of sinusitis and bilateral enlargement of tonsils and adenoids that interferes with his sleep. Bilateral conductive hearing loss was also present. As per routine a chest X-ray was taken. What could be the probable underlying defect?

Source: Ponnathpur L & Shantharam L. Indian Journal of Clinical Practice, Vol. 24, No. 2, July 2013.