Caudal migration of the verumontanum.

The location anomaly of the verumontanum has not been described in the literature. We confirmed that the verumontanum was located either in the sphincteric or bulbous urethra in 61 of 477 patients with hypospadias (12.8%) through endoscopic examination and urethorgraphy. There was a patient with bilateral cryptorchidism who had distal location of the verumontanum. The patients with hypospadias and caudal migration of the verumontanum showed significantly low response of testosterone to human chorionic gonadotropin stimulation compared with normal controls. The incidence of caudal migration of the verumontanum was higher in the patients with a severe degree of hypospadias than in those with mild hypospadias. These results suggest that distal location of the verumontanum may be the result of an insufficient action of androgens during the period of critical sexual differentiation in the male embryo. We call this phenomenon caudal migration of the verumontanum, which seems to be a new clinical entity.