**Question:** Hirschsprung disease, marker - used for early diagnosis -

A. Chloroacetate esterase
B. Alcian blue
C. Sudan Black B
D. Alcian blue and PAS (periodic acid-Schiff)

**Core Concept:** Hirschsprung disease is a congenital malformation characterized by the absence of ganglion cells in the myenteric and submucosal plexus of the colon, leading to impaired bowel motility and constipation.

**Why the Correct Answer is Right:** The correct answer, D (Alcian blue and PAS), is a histopathological staining technique used for early diagnosis of Hirschsprung disease. Alcian blue stains the mucusproducing goblet cells, while PAS (Periodic Acid-Schiff) stains the mucopolysaccharides, including the mucin in the mucus. In Hirschsprung disease, the absence of ganglion cells leads to reduced mucus production, resulting in fewer goblet cells and decreased mucin content. Combining Alcian blue (to demonstrate the absence of goblet cells) and PAS (to demonstrate reduced mucin) helps in confirming the diagnosis of Hirschsprung disease.

**Why Each Wrong Option is Incorrect:**

A. Chloroacetate esterase (a marker for nerve cells) is not specific for Hirschsprung disease diagnosis, as it can be present in ganglion cells in the affected area.

B. Alcian blue alone is not sufficient for diagnosis, as it can reveal a reduced number of goblet cells in other conditions like inflammatory bowel diseases or pseudo Hirschsprung disease.

C. Sudan Black B is a marker for fat droplets and is not relevant for diagnosing Hirschsprung disease.

**Clinical Pearl:** Early diagnosis and management of Hirschsprung disease is crucial, as it can lead to better surgical outcomes and reduced complications. In suspected cases, a combination of Alcian blue and PAS staining is essential for confirming the diagnosis. Further investigations like rectal biopsy and measurement of rectal mucosal potential difference can also be done for conclusive diagnosis.