The neurovascular and muscular anomalies of the gluteal region: an atypical pudendal nerve.

In two cases, one male and one female, muscular anomalies together with neurovascular variations were encountered in the gluteal regions, in each cadaver on the same side. In the male cadaver, there was a double piriformis muscle and high division of the sciatic nerve. In the female cadaver, in addition to these anomalies, the superior and inferior gemelli and obturator internus muscles, and the internal pudendal vessels and pudendal nerve passed behind the sacrotuberous ligament. Although duplication of the piriformis and high division of the sciatic nerve have been reported previously, to the best of our knowledge the other anomalies have not yet been reported. The abnormal relationship of the internal pudendal vessels and the pudendal nerve with the sacrotuberal ligament, as in our case, may cause venous congestion, arterial obstruction, dysfunction of penile erection and perineal neuralgia. These anomalies of the gluteal region are not only of academic interest, but may be of practical importance for surgical intervention in the area.