A worrying lesion for resection?

This 13mm colonic lesion has been referred for resection
WHAT IS YOUR PREDICTED HISTOLOGY?

■ Benign adenoma

No way! This looks like cancer!

■ SM1 cancer

This was our own diagnosis although the non-lifting was of a more advanced lesion!

■ SM3 cancer

Doesn't really look like it but this was the CORRECT answer!

■ T2 cancer

Wrong because the lesion should then have NO crypt pattern

explanation

Histology had 'informed us' that this was a TA+HGD.  But of course, Endoscopically this IS A CANCER!   'Newbies to endoscopy' may wonder how I can be sure? 

Simply, this is what early colorectal cancer looks like !!!   Of course, some cancers are hidden deep within larger, sessile or pedunculated polyp and can not be glimpsed from any disturbance of the polyp surface. That is a separate issue and no amount of experience can help you with the chance finding of cancer buried deep within such a polyp.  

Attempting to find the words to describe the features which are 'malignant' is difficult. Firstly the lesion is firm! If you can reach it with a finger, you will find that it's hard to the touch. If you can poke it with the biopsy forceps you will find that it moves like a solid disc of firm tissue.  It's also the elevated margin surrounding an angrily red centre which has a different crypt pattern is another feature.  

Actually, there does appear to be some sort of crypt pattern in the centre.  Endoscopically we had diagnosed sm1 invasion (i.e. invading into the top 1mm of the submucosal layer).  Surprisingly, it didn't lift at all and because the patient was not a surgical candidate, we offered a 'full thickness resection' (images below). 

Rather surprisingly, the final diagnosis was of sm3 invasion with LVI!   With time you will find that removing cancers endoscopically never leaves you with absolute 'peace of mind'.  There is always some adverse feature to keep you awake at night!