A complete success?

This colonic polyp was removed as a single fragment from a 60 year old lady. You can see the mucosal defect in the last image. The patient asks you what will happen next? 
WHAT WILL YOU REPLY?

a) Can't tell, we will have to wait for the histology

You can do better!

b) In all likelihood there will be a site-check in 4 month or so

You are missing something!

c) Next examination will probably be in 3 years

No!

d) You will probably need an operation

You've spotted the desmoplastic reaction!

explanation

The polyp looks very suspicious but did seem to lift and I therefore decided to go ahead and removed it using a stiff, large snare.  It took a little longer than expected for the snare to cut through. Of course, the mucosal defect should be blue. In this case it's yellow!  The polyp was malignant, invading about 1mm into the submucosa and you are looking at the 'desmoplastic' reaction generated by the cancer.   

Apart from the sometimes deceptive 'non-lifting sign', there are two further signs that a lesion may be malignant. First, it may look smaller and smaller as you inject below the lesion (see example below).  Another sign is that your blue sub-mucosal injection appears to lift the lesion until you retrovert and have a look at the other side. If you then find that it hasn't actually 'crossed the mid-line', there is fibrosis below the lesion preventing the fluid to disperse evenly. 

I was not entirely surprised to learn that the patient declined surgery. After all, he was 86 years old!  He lived another 7 years and never developed any sign of bowel cancer. 

By the way, there is a theoretical risk of tumour seeding if the lesion is perforated during resection. However, when the perforation is done with a red-hot tool such as a knife or snare, the risk of seeding is surprisingly low. I have perforated a handful of cancers but have never had a case of late disseminated peritoneal disease. My Japanese colleagues (off the record), agree that the risk is there (some have seen it) but is low. 

If you decide to sample a suspicious looking polyp, you shouldn't use the same forceps to sample another lesion.  This is because if cancer cells become lodged in the biopsy forceps, which are then used to sample another location and them become stuck in the biopsy, the histopathologist will diagnose cancer in TWO locations when in fact, there is only a single cancer.