Age / Sex : 60 / M

Meralgia paresthetica (lateral femoral cutaneous nerve neuropathy)

Discussion

Answer: meralgia
paresthetica (lateral femoral cutaneous nerve neuropathy)

Findings: Axial
T2, T1-weighted MR images show enlargement of the left lateral femoral
cutaneous nerve. Axial fat-suppressed T2-weighted MR image shows perineural
soft tissue edema.

Differential Diagnosis:

Diagnosis:
meralgia paresthetica (lateral femoral cutaneous nerve neuropathy)

Discussion:

The lateral femoral cutaneous nerve is a sensory nerve arising from the
dorsal division of 2^nd and 3^rd lumbar nerves. It emerges
from the lateral aspect of the psoas, crosses anterior surface of the iliacus,
toward the anterior superior iliac spine. After passing under the inguinal
ligament, the nerve branches into anterior and posterior branches, which
penetrate through the fascia lata, and provide sensory innervation to the
anterior and lateral thigh.

Neuropathy of the lateral femoral cutaneous nerve, commonly known as
meralgia paresthetica, presents as paresthesias in the anterolateral thigh. It
is most commonly caused by mechanical compression at the level of the inguinal
ligament, such as constricting clothes, tool belts, and set belts.

References: MR Imaging of Entrapment Neuropathies
of the Lower Extremity Part 1. The Pelvis and Hip¹ Radiographics 2010; 30:
983-1000