Master the board step 3

Pediatrics
Hematochezia
A 2-year-old boy is brought to the office because his mother has noticed bleeding
in his diaper for 1 week. The child has had no complaints. Physical examination is
unremarkable. Which of the following is the best initial test?
a. Guaiac exam
b. Push enteroscopy
c. Red blood cell tagged scan
d. Tc-99m pertechnetate scan
e. Upper endoscopy
Answer: D. The Tc-99m pertechnetate scan is also known as the Meckel radionuclide
scan, the diagnostic exam for Meckel diverticulum. Intermittent, painless rectal bleeding
is the classic presentation due to acid-related bleeding of aberrant mucosa (remnant
of embryonic yolk sac). May present with intussusception (remnant may become a lead
point) or diverticulitis or look like acute appendicitis.
Meckel diverticulum is a remnant of the omphalomesenteric duct. It follows
the rule of 2’s:
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2 percent of the population have it
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2 feet from the ileocecal valve
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2 inches in length
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2:1 male to female
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2 types of tissue (gastric and pancreatic)
Meckel Diverticulum
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