An easily missed lesion

a) Reflux oesophagitis

An irregular squamo-columnar junction does suggest previous reflux oesophagitis but in this case there is more...

b) Non-dysplastic short segment Barrett's

Short-segment Barrett's is defined as Barrett's up to 3cm. In contrast, 'ultra-short Barrett's is less than 1cm. We sized the Barrett's as C0/M2 (according to the Prague classification). However, it doesn't look non-dysplastic!

c) Barrett's with intra-mucosal cancer

This would have been my own guess. There is no 'thickness' to the lesion and there is no ulceration, two features which would suggest that the lesion can't be removed endoscopically

d) Siewert II invasive cancer

Of course it may be invasive but that would be a little surprising. Endoscopically, this is IMca. Similarly HGD is unlikely as there is a lot of mucosal irregularity and you can see something has infiltrated below part of the squamous mucosa in the 2 o'clock position.

explanation

As you know, most of the time Barrett's neoplasia develops on the right-hand side and in the distal (rather than the proximal) Barrett's segment. In this case, in the 2 o'clock position there is a subtle mucosal irregularity. In fact, there appears to be something infiltrating below the squamous mucosa at this location. Biopsies had suggested IMca and a CT had been reassuring. Because the lesion is endoscopically resectable, we didn't bother with an EUS. The lesion was removed and confirmed as a poorly differentiated adenocarcinoma with signet ring morphology. On the other hand, all margins were clear and there was no LVI (lympho-vascular invasion).  In the hierarchy of poor prognostic features, LVI and depth of invasion (>500µm) are the most important whilst poor differentiation is the least important. Nevertheless, I was a little worried when the patient declined surgery...