“DO YOU LOOK FOR FLAT POLYPS?”
Gastroenterologists were being asked this question by patients about this time last year, when the New York Times published this story about flat polyps. If you haven’t already read it, it’s worth reading.
A “flat polyp” is, well, flat. Refer back to my March 4th blog entitled “What is a Polyp Anyway?” where I describe the shapes of polyps as principally either “sessile” (mushroom cap) or “pedunculated” (on a stem, like a lollipop).
Add to this that sometimes the “sessile” ones are actually “flat” - or hardly raised… or could even be sunk-in a bit, “depressed.” See diagram.
While colonoscopy is currently the “gold standard” (i.e. “best we have”/”most recommended”) test to screen for colon cancer and pre-cancerous polyps, admittedly it, like everything else in life (and therefore science & medicine) is not perfect… things can rarely be missed.
Thankfully it is under 1% of cases in which a person still develops colon cancer within a few years of having had a colonoscopy.
How can this happen?
Since we believe that most, if not all, colon cancer comes from “pre-cancerous polyps,” it may be the case when this happens that either:
- A polyp was missed on the prior colonoscopy, which therefore grew and transformed into colon cancer, or
- A new polyp emerged and quickly transformed into colon cancer
In the case of a polyp being missed, admittedly these “flat polyps” can be subtle, hard to find, and could be missed. For example, see how subtle the below flat polyp is (especially compared to some of the other polyps I’ve shown pictures of this month):
- Flat polyp - seen by texture change…
You can see the polyp here because you can sense the change of “texture” of the tissue - not because it has any significant “raised” 3-D quality. This, by the way, is one of the concerns gastroenterologists have for “Virtual Colonoscopy,” which I suspect would have missed this sizeable pre-cancerous polyp.
The answer to the original question is “Yes, a skilled ‘endoscopist’ (someone who does colonoscopies) does look for, and remove, flat polyps.”
- Now you see it….
- …now you don’t.
It is should not come as a surprise then that it has been shown that doctors are more skilled at colonoscopy (and thus identifying hard to reach or hard to find polyps) when colonoscopy comprises a significant portion of their medical practice and they do many (hundreds) of colonoscopies each year…
