Duplication cyst of the pylorus--a rare cause of gastric outlet obstruction in the newborn.

Duplication cysts of the pylorus are the rarest of alimentary tract duplications with very few reported cases. We present such a cyst in a neonate presenting with gastric outlet obstruction. We have also reviewed the literature and outlined the theories of origin, modes of presentation, diagnosis and the surgical procedures. Even though several modes of surgery have been described, it is best to individualize the surgical option in each case. The results depend on the nature and site of duplication, complications and the associated anomalies.