Urachal carcinoma.

Urachal carcinoma is a rare tumor that often does not manifest clinically until late in its course. Several radiographic features are helpful in suggesting the diagnosis preoperatively. We present a case of urachal carcinoma in which preoperative evaluation included magnetic resonance imaging. This technique was helpful not only in suggesting the diagnosis preoperatively, but also, and more importantly, in the preoperative staging of the neoplasm.