1981 Volume 23 Issue 2 Pages 241-247
Tiny white spots were found in the surrounding mucosa of 7 out of 21 removed polyps via colonoscope, all of which were histologically malignant. These white spots were best observed under colonoscopy and revealed histologically a collection of foamy cells just below the surface epithelium between tubules with faintly stained granules by H & E stain-ing. They were also seen in the adjacent mucosa of frank carcinomas and histological study of 100 consecutive colorectal carcinomas showed these foamy cells in 32 percent. Histochemically they were positive by PAS, alcian blue, mucicarmine and toluidine blue but negative by oil red O, showing most similar property of ′muciphages′ described by Azzopardi et al. In the surrounding mucosa of a large pedunculated adenoma and several adenomas in adenomatosis coli these white spots were also noticed. However, the presence of white spots seems to be a usefule marker for the colonoscopic diagnosis of focal and invasive carcinoma, although they were exceptionally found in other conditions such as ulcerative colitis and benign adenomas. The nature of these white spote were discussed and clinical usefulness of this findings was stressed.