What does the 'lead pipe sign' indicate in a patient with UC?

• A. Strictures of the intestines
• B. Absence of haustra
• C. Skip lesions
• D. Hemorrhagic transformation

Answer: (B)

The 'lead pipe sign' is a classic radiological finding associated with ulcerative colitis (UC) and is characterized by the loss of the normal haustral pattern of the colon, resulting in a straight, tubular appearance similar to that of a lead pipe. This sign appears on imaging studies such as barium enema or CT scans and indicates a significant alteration in the colonic mucosa due to inflammation and ulceration associated with UC.

In ulcerative colitis, this change is typically due to extensive mucosal involvement, leading to a uniform and smooth contour of the colon without the characteristic outpouching of haustra, which are normally seen in healthy individuals. The absence of haustra is indicative of the continuous nature of ulcerative colitis, as opposed to Crohn's disease, which commonly exhibits skip lesions and can produce strictures or transmural disease.

The other options relate to different aspects of colonic pathology that are not typical for ulcerative colitis in the context of the 'lead pipe sign.'