[Urachal cyst. Report of 3 cases]

The authors report three cases of cyst of the urachus, one of which was complicated by infection. This diagnosis is only rarely established clinically. The current performance of ultrasonography allows very precise analysis of the anterosuperior surface of the bladder, which may reveal the diagnosis. The authors discuss the problems raised by cysts of the urachus and emphasize the importance of clinical history, physical examination and complementary investigations, particularly CT which should allow the diagnosis of this disease, which needs to be treated surgically.