Review Question - QID 101902

The patient presented in this question is suffering from Hirschprung's disease (HD). Hirschprung's is caused by failure of neural crest cell migration.

In normal fetal development, neural crest cells migrate caudally through the intestine and form Meissner's and Auerbach's plexi in the wall of the bowel. Hirschsprung’s disease results when this migration fails. Without ganglion cells, the bowel cannot relax and consequently, the lumen remains narrow. Passage of intestinal contents is compromised, resulting in abdominal distension, vomiting, and sometimes failure to pass meconium. The disease ranges in severity depending on how much of the colon is affected, but the rectum is always involved due to the direction of cell migration. The disease is treated with resection of aganglionic colon segments. Any failure of neural crest cell migration (abnormal teeth, duodenal atresia, Hirschprung's) should prompt the clinician to think of trisomy 21.

Kessmann provides a useful review of HD. HD, also known as congenital megacolon, is caused by a failure during embyogenesis of the colonic ganglion cells to appropriately migrate. Without these ganglion cells, various portions of the distal colon are unable to relax, thus causing a colonic obstruction. Although HD most commonly affects the rectosigmoid colon, it is capable of acting on the entire colon and even small intestine. HD commonly presents in infancy with difficult bowel movements, poor feeding, poor weight gain, and progressive abdominal distention. It is important to make the diagnosis early so as to prevent unwanted complications (e.g., enterocolitis, colonic rupture).

Rintala et al. discuss the long-term outcomes of HD. HD patients were noted to have lower scores of overall bowel function compared to healthy controls. Despite having a deteriorating quality of life secondary to their disease, most adult HD patients were found to be able to function as normal members of society. As a whole, they seem to be well adapted to the psychosocial, occupational, and recreational activities of daily living. HD patients are however at risk of developing disease-associated conditions, and as such, will require specific screening programs throughout their adult lives.

Illustration A depicts two separate images. The left image shows a normal colon, whereas the right image shows a colon affected by Hirschprung's disease.

Incorrect answers:
Answer 1: Pyloric stenosis may be caused by hypertrophy of the pyloric sphincter. It presents with non-bilious vomiting in a neonate.
Answer 2: Mechanical obstruction would be unusual in the case of a newborn with no history of foreign bowel ingestion or prior abdominal surgeries, who is otherwise developmentally (anatomically) normal.
Answer 3: CFTR gene mutation is the cause of cystic fibrosis (CF). Both CF and Hirschprung's may present with failure to pass meconium. The contrast enema described in the question stem is more consistent with Hirschprung's disease.
Answer 4: Meiotic nondisjunction can result in Trisomy 21, Down syndrome. Down syndrome may present with duodenal atresia, which presents with the double bubble sign on abdominal radiograph.