Anatomic Variation in Patient with Lateral Femoral Cutaneous Nerve Entrapment Neuropathy

BACKGROUND: We report a surgical case of entrapment neuropathy of lateral femoral cutaneous nerve (LFCN) with anatomical variation. CASE DESCRIPTION: This 53-year-old man had a 10-year history of paresthesia and pain in the right anterolateral thigh exacerbated by prolonged standing and walking. His symptoms improved completely but transiently by LFCN block. The diagnosis was LFCN entrapment. Because additional treatment with drugs and repeat LFCN block was ineffective, we performed surgical decompression under local anesthesia. A nerve stimulator located the LFCN 4.5 cm medial to the anterior superior iliac spine. It formed a sharp curve and was embedded in connective tissue. Proximal dissection showed it to run parallel to the femoral nerve at the level of the inguinal ligament. The inguinal ligament was partially released to complete dissection/release. Postoperatively, his symptoms improved and the numeric rating scale fell from 8 to 1. CONCLUSION: We report a rare anatomical variation in the course of the LFCN.