OMED E-Newsletter Issue 9, 2010: Brainteaser/image of the month
This lesion was found in the descending colon of a patient undergoing colonoscopy for anaemia.
What type of lesion is this?
- hyperplastic polyp
- tubular adenoma
- tubulovillous adenoma
- villous adenoma
- serrated adenoma
Explanation
Option D is correct. This polyp has finger-like projections. Tubulovillous adenomas have a cerebrate of gyrate-like pattern. Even if the villous morphology is not obvious on observation, it will become obvious if you would try to sample the lesion by biopsy. The forceps will seem to disappear into the soft, villous surface. Alternatively, submerging the polyp will allow the villi to be observed as they wave about in the water.
Dye spraying is often disappointing in villous adenomas as their thick coverage of mucus prevents the dye from entering the mucosa.