Cyclic sciatica related to an extrapelvic endometriosis of the sciatic nerve: new concepts in surgical therapy.

Sciatic pain caused by endometriosis of the sciatic nerve is an uncommon clinical finding and seems to have been verified histologically in only a few cases. Patients complain of typical signs and symptoms of common sciatica that are cyclic in nature. Suggested compression of lumbar root or sciatic nerve or its plexus could be confirmed by electromyography, computed tomography, or magnetic resonance imaging, and by prompt response to hormonal suppression of ovarian function with regression of the radiologic findings. Patients often have required radical surgery with total hysterectomy and bilateral salpingo-oophorectomy. However, conservative surgery with excision of the endometriosis from the nerve can be successful in selected patients who wish to preserve reproductive function. We report a case of sciatic nerve involvement explored by magnetic resonance imaging, with endometriosis in contact with the nerve in the right sciatic trunk.