title: Segmental aganglionosis (zonal aganglionosis or "skip" lesions) in Hirschsprungs disease: a report of 2 unusual cases.
abstract: BACKGROUND
  There is accumulating evidence that "skip" lesions or zonal aganglionosis do occur in HSCR disease, albeit rarely. They are of interest because it may cause confusion in interpreting surgical margins as well as understanding the pathophysiology of HSCR disease. Normally described as "a skip area" of normally ganglionated bowel, surrounded proximally and distally by aganglionosis with variations may occur.
  
  
  METHODS
  We report two cases of infants with unusual types of "skip lesions", identified within the last 5 years.
  
  
  RESULTS
  One patient had an area of zonal aganglionosis in the transverse colon and recto-sigmoid, bordered by areas of normally enervated bowel in the right and descending colon. In the second patient, the terminal ileum, transverse, descending and sigmoid colons and rectum were histologically aganglionic, but focal patches of ganglion cells were identified in 21 cm of the right ascending colon and the appendix, suggesting some ENS plasticity and possible incomplete apoptosis.
  
  
  CONCLUSIONS
  These cases illustrate the point that the presence of ganglion cells at the resection line is not sufficient to guarantee postoperative function and "skip" lesions may uncommonly confuse the picture. In addition, they raise questions as to its pathophysiology and favor an alternate hypothesis of local changes promoting neuroblast apoptosis as the possible cause.
authors: Division of Pediatric Surgery, Department of Surgical Sciences, Faculty of Health Sciences, University of Stellenbosch, PO Box 19063, Tygerberg 7505, South Africa. SWM@sun.ac.za
authors: S W
authors: SW
authors: Moore
authors: D
authors: D
authors: Sidler
authors: P A W
authors: PA
authors: Schubert
mesh_terms: D001065:Appendix / Q000473:pathology; D003106:Colon / Q000473:pathology; D005260:Female; D006627:Hirschsprung Disease / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007082:Ileum / Q000473:pathology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D012007:Rectum / Q000473:pathology