CT for BRRB ?!?

This 80 yr old man was first referred for a CT to investigate his PR bleeding and mucus. The CT reported that the rectum appeared thickened and a Flex Sig is organised
WHAT IS YOUR DIAGNOSIS?

■ Active proctitis with inflammatory polyp

That was my diagnosis and I was half correct!

■ Active proctitis with adenomatous polyp

Very good call!!! Better than mine if fact!

■ Circumferential polyp with dominant nodule

Apologies for the indigo carmine dye which has confused you!

■ Circumferential polyp with malignant change

The blue dye is confusing and the proctitis does look weird in places

explanation

Yes, it does seem odd to refer for a CT rather than a Flex Sig?  Perhaps this was because the patient was 80 yrs old or because of our endoscopy waiting list.  Anyway, I was half correct. I diagnosed an active colitis and histology confirmed a: transmucosal inflammation with crypt abscess and focal epithelial loss (tiny, tiny ulcers).

​We all know that active colitis is characterised by an dull erythema, bleeding and erosions/ulcers. The best endoscopic scoring system is currently the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) which scores these three parameters on a scale of 0 to 3. There are other scoring systems of course such as the Mayo score, the Baron score, The Rachmilewitz Endoscopic Index, The Sutherland Index, The Matts Score, The Blackstone Index and the most recent addission, The Ulcerative Colitis Colonoscopic Index of Severity!  Of course this tells you than none of them is the last word on the topic. 

For a good review of all endoscopic issues relating to colitis, please check this article out; Annese V. European evidence based consensus for endoscopy in inflammatory bowel disease, J Crohn's Colitis 2013;7(12);982-1018

Anyway, I find it odd that other common features of an active colitis are not included in any of these scoring systems.  This includes mucosal oedema, a villous epithelial surface (as seen in this video) and a mucopurulent discharge (which I regard as feature of a severe attack of colitis). 

These three features are prominent in this video and if not recognised as features of an active colitis, can be mistaken for a neoplastic process. 

​I thought that the nodule would be inflammatory but it turned out to be a 'TSA' (traditional serrated adenoma), the most rare and elusive of all colorectal polyps.  Well I blame the inflammation and that thin mucopurulent layer obscuring the crypt pattern.