Neonatal intestinal obstruction simulating meconium ileus in infants with long-segment intestinal aganglionosis: radiographic findings that prompt the need for rectal biopsy

Background: The initial clinical presentation and radiographic finding of microcolon in children with long-segment intestinal aganglionosis involving the entire colon, ileum and sometimes the jejunum can mimic meconium ileus. This makes the diagnosis difficult for the radiologist and surgeon. Objective: To document and describe the clinical and radiographic findings in children with long-segment intestinal aganglionosis who are initially thought to have meconium ileus. Materials and methods: We reviewed the cases of six neonates with long-segment intestinal aganglionosis presenting as meconium ileus at our institutions between 1978 and 2002. We examined the clinical presentation and the radiographic, surgical, and pathologic findings. In addition, 17 cases from the literature were identified and are included in the discussion. Results: A total of 23 cases were reviewed. Right lower quadrant intraluminal calcifications were noted on abdominal radiographs in all six neonates of our series and were described in 13 of the 17 neonates reported in the literature. Similarly, a microcolon was present in five of the six neonates of our series and in 14 of 16 historical neonates (one not reported). Conclusion: In a neonate with small-bowel obstruction and a microcolon, the presence of right lower quadrant intraluminal calcifications should raise the suspicion of long-segment intestinal aganglionosis even if the operative findings are typical of meconium ileus and a biopsy should be performed.