Grafting of stomach tissue into the duodenum in F344 rats results in chimeric crypts and tumor development.

: Gastric tissue was transplanted from the fundic and pyloric mucosa of 8-week old female F344 rats into the duodenum of males. Autopsy, 12 months after the operation, revealed grafts associated with persistent stones in the duodenum and/or calcification in the tissue. Pepsinogen positive chimeric glands with goblet cells also appeared in the grafts which gave rise to tumors in 18 out of 45 animals (40%). In conclusion, stomach grafts re-differentiate into intestine with goblet cells in the duodenum and this process predisposes to tumor development.