[Schwannoma and the urinary tract. Concerning a tumor of the obdurator nerve].

Peripheral nerve tumours, called schwannomas, because they are derived from cells of the Schwann sheath, are rare tumours that can involve any part of the body, but are essentially located on the limbs, which represent more than 50% of cases. Schwannomas of the trunk and especially pelvic schwannomas are even rarer. A tumour arising from the obturator nerve is exceptional, but its paravesical location can facilitate the diagnosis, as in this case. The complementary investigations most frequently performed are CT and MRI, although they are unable to define the exact nature of the tumour. Surgery must try to preserve continuity of the nerve, but that is not always possible and does not appear to have any major consequences in this site.