Question
A 3-year-old boy is brought to the emergency department by his parents after he develops acute abdominal pain and vomiting. Imaging studies reveal a foreign body lodged within his intestine causing a small bowel obstruction. Laparotomy is performed to remove the foreign body; during the procedure, an incidental abdominal cyst is discovered and removed. The cyst is connected by a fibrous band to the ileum and the umbilicus. Which of the following conditions is also caused by the same embryological defect responsible for this patient’s abdominal cyst:
| A. |
Duodenal atresia
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| B. |
Meckel diverticulum
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| C. |
Umbilical hernia
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| D. |
Omphalocele
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Show Answer
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Correct Answer � B
Explanation
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Ans. B. Meckel diverticulum
Explanation:The omphalomesenteric (vitelline) duct connects the midgut lumen with the yolk sac cavity early in embryonic life. It normally obliterates during the 7th week of embryonic development. If its obliteration is incomplete or abnormal, several abnormalities can result:
1. A persistent vitelline duct, or vitelline fistula, occurs due to complete failure of the vitelline duct to close. A small connection between the intestinal lumen and the outside of the body exists at the umbilicus. Meconium discharge from the umbilicus is seen soon after birth if such a fistula is present.
2. Meckel diverticulum is the most common vitelline duct anomaly. It results from a partial closure of the vitelline duct, with the patent portion attached to the ileum. A fibrous band may connect the tip of the Meckel diverticulum with the umbilicus.
3. Vitelline sinus results from a partial closure of the vitelline duct, with the patent portion open at the umbilicus.
4. Vitelline duct cyst (enterocyst) forms if peripheral portions of the vitelline duct (connected to the ileum and umbilicus) obliterate, but the central part remains. This cyst is connected with the ileum and abdominal wall by fibrous bands. Most vitelline duct abnormalities are asymptomatic and often discovered incidentally. However, the Meckel diverticulum may present with rectal bleeding or intestinal obstruction. Remember the rule of 2’s with Meckel diverticulum: 2% of the population, 2 feet from the ileocecal valve, 2 inches in length, 2% are symptomatic, and males are 2 times more likely to be affected.
