WHEN intermittent pyloric obstruction is associated with a large, freely movable mass in the upper region of the abdomen, the congenital anomalies of this area must be remembered. Although duplications of the stomach are rare in occurrence, with only a small number having been reported in the literature, they should not be disregarded for practical purposes. The number that any surgeon will see will be few, but he should be cognizant of their existence, recognize them at the time of operation and know how to treat them, especially when they occur in adults.
Duplications of the stomach may be intimately associated with the normal stomach or be removed from the area usually occupied by that organ. The walls of the cysts are complete or incomplete reproductions of the normal structure. When the duplication which is isolated from the organ is reproduced, the entire four layers of usual gastrointestinal wall may