From zero to polyp in...?

August 29, 2019 6:47 PM

I had a colonoscopy on July 9th, during which a 20mm polyp was found and because [reasons] was only partially removed. I made an appointment with a specialist who would able to remove the remainder of the polyp in an outpatient setting during what would amount to another colonoscopy. So, six weeks after the original colonoscopy, I had the second procedure. The surgeon removed the rest of the polyp and found (and removed) two additional 20mm polyps.

So, just how quickly do polyps grow? Could the two “new” ones really be new, or did the first doctor miss them? The only info I am able to find on line tells me how quickly polyps become cancerous. I cannot seem to find any information about how quickly polyps develop in the first place.

Any insight into this will be greatly appreciated.

YANMD, etc.

posted by Dolley to Health & Fitness (2 answers total)

Best answer: Polyps do not grow quickly enough to get from 0 mm to 20 mm in a few weeks.
The new-found polyps were already there during your first colonoscopy. For all the great benefits of colonoscopy, it does not guarantee detection of all polyps. One study found that when tandem colonoscopies were performed in a few hundred patients (two subsequent colonoscopies done by two different endoscopists), 22 percent of polyps were missed the first time around. Most of the missed polyps were small (under 5 mm) and very unlikely to be malignant; polyps over 10 mm had a 2 per cent miss rate.
Reasons for missed polyps include poor colon preparation (too much residual stool - in this case the procedure is often abandoned or the patient is informed and scheduled for an early repeat procedure), polyps located in difficult to visualize places (flat polyps behind colonic folds especially), insufficient time spend on examining the mucosa during scope withdrawal, inexperienced endoscopist (one quality indicator is the average adenoma detection rate or ADR), location in the right colon where the polyps are often flat.
The endoscopist should recommend an appropriate re-screening interval when the pathology report becomes available. The pathology report will include information on whether or not the polyp was removed completely at the microscopic level.
Hope this helps.
posted by M. at 10:19 PM on August 29, 2019 [11 favorites]

Also this should probably go without saying, after finding a missed polyp I'd make sure the entire colon was scoped the second time around, not just the segment with the incompletely removed one. Another thing to pay attention to, is whether the quality of the prep was described as at least adequate for each segment of the colon during that second procedure. This is standard but I'd check just in case.
posted by M. at 10:51 PM on August 31, 2019