Radiographic herald lesion of the urinary bladder: pictorial essay.

At cystoscopy a focal mucosal abnormality may be indicative of a pathological process extrinsic to the urinary bladder and has been termed 'the herald lesion'. The aim of the present pictorial essay was to describe the radiographic counterpart to this cystoscopic finding. Radiographic herald lesions are shown in patients with extravesical inflammatory (Crohn's disease, colonic diverticulitis and pelvic inflammatory disease) and neoplastic (colon carcinoma) processes, and urinary tract complications of these conditions are described and illustrated.