<prompt> This clinical sign is seen inCarcinoma colonUlcerative colitisCrohns diseaseTuberculosis  <response>: This is a contrast study showing string sign of KantorIn Crohn;s disease, edema, bowel wall thickening, and fibrosis of the bowel wall within the mass account for the radiographic string sign of a narrowed intestinal lumen.Ref: Harrison 19e pg: 1953 