This 'lesion' was barely visible within in a Barrett's segment on white light. However, after acetic acid and with NBI it's more obvious.
WHAT IS THE LIKELY HISTOLOGY?
a) Barrett's LGD
Usually invisible or just a red, flat patch
Subtle change in crypt pattern but with little nodularity?
This was my own guess but it was wrong...
d) Invasive cancer
Yes, superficial invasion (100 microns) and poor differentiation!
I removed this lesion without worrying too much about the subtle 'depressed' growth pattern and the small, round crypts in the centre of the lesion. However, I was surprised to see the pathology report of a superficially invading adenocarcinoma, with poor differentiation to boot!!! This finding makes the advice on 'further treatment' more complex. As you know, in both the upper and lower GI tract, the finding of 'lymphovascular invasion' (LV) is probably the most 'ominous sign' that a patient needs surgery (or chemo-radiotherapy in case of the oesophagus). Poor differentiation is 'bad', but less bad than LVI.
Depth of invasion is also important and in Barrett's you are 'allowed' invasion to about 500 microns below the muscularis mucosa. The corresponding 'safe margin' in SCC's is only 200microns. In this case the depth of invasion was only about 100 microns, leaving 'poor differentiation' as the only 'bad sign'. The patient wasn't a surgical candidate and refused CRT. This was 3 years ago and so far all is well!
By the way, the histopathologists do have a more difficult job than you perhaps imagine, measuring the depth of invasion in Barrett's cancer. This is because they often see several bands of muscularis mucosa, so called 'duplication of the muscularis mucosa'. Elsewhere in the GI tract, the muscularis mucosa is a single band of smooth muscle. They measure the depth of invasion from the top of the muscularis mucosa down the the deepest point of invasion. However, if there are several bands of muscularis mucosa, which one do you measure from?!? Below is an example to illustrate the dilemma.