The 'tulip sign': A sonographic clue for in-utero diagnosis of severe hypospadias

Objective: To describe a unique sonographic sign for prenatal detection of severe penoscrotal hypospadias. Methods: Ultrasound findings of hypospadias diagnosed in the second trimester of pregnancy in seven patients were compared with postnatal clinical features. All patients were recruited from routine sonographic examinations performed for various obstetric indications. Results: In six of the seven cases with hypospadias, a severe form of peno-scrotal hypospadias was found. In all six cases, a unique ultrasound feature was observed represented by extreme ventral angulation of the penis, with or without chordee, in a form resembling a tulip flower. This 'tulip' is formed by the ventrally bent penis located between the two scrotal folds. In all six patients, the postnatal pictures of the newborns' genitalia corresponded perfectly to the prenatal sonograms. Associated anomalies occurred in two cases, with Nager syndrome in one case and mild renal hydronephrosis in the other case. Conclusions: The 'tulip sign' is a specific ultrasonic finding of severe hypospadias. The recognition of this may help to distinguish between severe hypospadias and other genital abnormalities (e.g. ambiguous genitalia).