Sonographic diagnosis of urethral polyp in a child.

Congenital urethral polyps are an uncommon cause of urethral obstruction in male children. The diagnosis is obtained at voiding cystography by demonstrating a filling defect which (typically) moves during micturition. A small polypoid mass with a stalk arising from the region of the verumontanum was observed by sonography in one such patient. We believe sonographic findings may be considered specific of this condition.