A 6-month-old infant with delayed passage of meconium, abdominal distension, and explosive stools after rectal stimulation. Barium enema shows a narrow rectosigmoid segment with a transition zone to a dilated proximal colon. This condition is characterized by absence of:

• A Goblet cells in the mucosa
• B Ganglion cells in the myenteric plexus ✓
• C Smooth muscle in the muscularis propria
• D Lymphatic drainage in the submucosa

Explanation

Hirschsprung disease is caused by absence of ganglion cells in the myenteric (Auerbach) and submucosal (Meissner) plexuses, resulting in a narrow, aperistaltic segment with a transition zone to dilated proximal colon on barium enema. The aganglionosis is due to failure of neural crest cell migration during embryogenesis. The other options are not the pathognomonic defect.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.