Intraepithelial bodies in colorectal adenomas: Leuchtenberger bodies revisited. The presence of intraepithelial inclusion bodies (Leuchtenberger bodies) was recorded in rectal or colonic specimens from 130 patients. Large to moderate number of intraepithelial bodies were recorded in 81.8 percent of 55 colorectal adenomas from patients with familial adenomatous polyposis (FAP). Conversely, none of the 55 non-FAP adenomas or of the 20 specimens with ulcerative colitis (10 with dysplasia) had similar amounts of intraepithelial granules. Feulgen studies demonstrated that the granules contain DNA and are probably nuclear fragments of destroyed lymphocytes. Although the pathogenesis of this phenomenon remains obscure, it appears that the presence of large to moderate number of intraepithelial bodies in colorectal adenomas should strongly raise the suspicion of FAP. 