A Macroscopic Sign of an Often Unseen Diagnosis

A 72 year old lady presented with new, non-bloody diarrhoea. She was intermittently using Ibuprofen and had a family history of colorectal cancer. She underwent colonoscopy.
What is the classical feature observed at the ceacum? How can the diagnosis be confirmed? How should this be treated?

 

Submitted by PR Harvey, RA Boulton.

Department of Gastroenterology, University Hospital Birmingham, Birmingham, UK.

  • Phil Harvey

    Answer:

    The images demonstrate “cat-scratch” colon, an uncommon but well recognised finding in collagenous colitis.

    The Figure demonstrates sharply demarcated mucosal breaks perpendicular to the ceacal folds. These were fresh and bleeding with a similar appearance to a “cat-scratch”. The surrounding mucosa was oedematous but otherwise normal. “Cat-Scratch” colon is a rare endoscopic finding associated with collagenous colitis. It is hypothesised that temporary shattering of the sub-epithelial collagen band due to barotrauma at colonoscopy creates this stark appearance.

    Collagenous colitis is a sub-type of microscopic colitis, often presenting with watery diarrhoea, although bloody diarrhoea is rare. More females than males are affected with incidence peaking in the 5th decade. Diagnosis is by histology, demonstrating expansion of the sub epithelial collagen layer as the defining feature whilst macroscopic appearances at colonoscopy are often unremarkable.
    Initial treatment includes withdrawing precipitating medications including NSAIDs, statins and PPIs. The only UK licensed treatment is budesonide. Withdrawal of Ibuprofen led to significant symptomatic improvement in this case.