Ask The Experts - RadiologyWeb

	Return to the Ask the Experts home page
	When diagnosing acute diverticulitis (for exampe of sigma) there is often concern over whether the correct diagnosis is acute diverticulitis or whether there might be a colonic tumor. (Diverticula are quite common and therefore as a single criteria are not specific for either diagnosis). What diagnostic criteria do you use to recommend colonoscopy? There was a report that stated that if the length of the lesion is more than 8 cm - a safe diagnosis of acute diverticulitis can be made. Is that your experience too?
	Dr. Peter Buetow responds: No single criteria is specific for distinguishing transmural diverticulitis and colon cancer (either associated with perforation or with diverticular disease). The following are helpful clues: Clinical presentation — fever, pain, and leukocytosis all favor diverticulitis. Fluid in the sigmoid mesentery (seen as a triangular low density) is relatively specific for diverticulitis. As you mentioned, the length of the lesion— the longer the lesion, the more likely it is diverticulitis (but submucosal growth of adenocarcinoma can mimic this finding in rare cases). Are there other diverticuli? If not, I consider colon cancer. Tincture of time — a follow up scan; diverticulitis resolves. My threshold for sigmoidoscopy is extremely low, and I recommend it if any of the above findings make me think of colon cancer. Furthermore, if the patient is over 50 and has not had a sigmoidoscopy, they need it.