Meralgia paresthetica. An anatomical interpretation.

One hundred and ten lateral femoral cutaneous nerves of the thigh were dissected in 90 adult and 20 fetal cadavers. In 51 per cent of adult cases a significant enlargement or pseudoganglion was present in the area of the nerve where it passed under the guinal ligament to turn sharply downward onto the thigh. The histological examination of these pseudoganglions showed a thickened epineurium, perineurium and endoneurium. No pseudoganglions and no histological abnormalities were found in the fetal nerves. It is proposed that erect human posture, combined with the particular course of the lateral femoral cutaneous nerve are the causes of tension, mechanical friction, and irritation of the nerve, and contribute to the development of the pseudoganglion and play a role in the pathogenesis of idiopathic meralgia paresthetica.