Genital ambiguity and urogenital sinus anomalies: a new classification

Rink RC et al. (2005) A new classification for genital ambiguity and urogenital sinus anomalies. BJU Int 95: 638–642

Since the 1950s, pediatric urologists have used Prader's classification to describe cases of genital ambiguity, and have generally characterized urogenital sinus anomalies based on 'high' or 'low' urogenital confluence. Rink and colleagues have recently proposed a new system—termed PVE classification—which aims to provide more accurate descriptions of these highly variable abnormalities.

In the PVE system, 'P' documents the maximal length of the stretched phallus in its flaccid state, and phallic width measured ventrally from side to side. For example, 'P_3,1' would describe a case where the phallus is 3 cm long and 1 cm wide. Next, 'V' denotes the distance, in cm, from the vaginal confluence to the bladder neck and to the perineal meatus. These two measurements are made endoscopically, using a catheter as a guide. Finally, 'E' refers to the external genital appearance. This is based on the Prader numbers 1–5, with the addition of class '0' to represent normal anatomy, and class '6' to denote rare deviations that fall outside the other categories (for example, the blank or 'doll-like' perineum).

In summary, the PVE classification describes the phallic size, true location of the vaginal confluence, and the external genital appearance. Rink et al. hope that the system will be useful in the surgical management of genital ambiguity and urogenital sinus anomalies, and will allow more meaningful comparisons of surgical outcomes.