A 3-month-old infant has a history of bilious vomiting since birth, with intermittent episodes of abdominal distension. He passes meconium late and has ribbon-like stools. X-ray shows multiple air-fluid levels. Contrast enema shows a transition zone in the sigmoid colon with normal ganglion cells proximal to the zone. Rectal biopsy shows absence of ganglion cells. Acetylcholinesterase staining of the aganglionic segment would show:

• A Markedly increased acetylcholinesterase-staining nerve fibres in the lamina propria and muscularis mucosae ✓
• B Decreased acetylcholinesterase activity in the lamina propria and muscularis mucosae
• C Normal acetylcholinesterase pattern; ganglion cell absence is the only diagnostic finding
• D Complete absence of any acetylcholinesterase activity in the aganglionic segment

Explanation

Hirschsprung disease (congenital aganglionosis) is characterised histologically by absence of Meissner's and Auerbach's plexus ganglion cells in the aganglionic segment. Compensatorily, there is hypertrophy and proliferation of extrinsic (parasympathetic) nerve fibres in the lamina propria and muscularis mucosae, which show markedly increased acetylcholinesterase (AChE) staining. This AChE hyper-staining in the context of absent ganglion cells is the diagnostic histochemical pattern. AChE staining is not decreased — the nerve fibres proliferate without ganglia to control them.

Reference: Ghai Essential Pediatrics, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.