Sciatic Neuralgia Caused by May-Thurner Syndrome

Sciatic neuralgia (SN) is a type of pain commonly associated with lumbosacral radiculopathy. May-Thurner syndrome (MTS) is a disease characterized by venous congestion in the left common iliac vein (LCIV) due to right common iliac artery compression. A case of MTS with SN as the first presenting symptom is described. A 53-year-old man gradually developed left SN; however, radiologic examination showed no causal findings. Conservative medical treatment did not result in satisfactory pain relief. During the follow-up period, edema and brownish skin pigmentation were noted on the left crural region. Follow-up magnetic resonance imaging of lumbar spine revealed vascular enlargement around the spine and compression of the LCIV by the right common iliac artery. Furthermore, the left S1 nerve root was compressed by enlarged veins, which was thought to be the cause of the left S1 radiculopathy and SN. After the stenosed part of the LCIV was expanded, the pain and edema in the left leg disappeared. This is the first report of SN associated with MTS. MTS should be considered as one of the differential diagnoses of SN. Thus, symptoms such as pain, edema, and skin hyperpigmentation on the left leg should be closely noted. •Sciatic neuralgia can be caused by various disorders.•The authors describe a rare case of sciatic neuralgia caused by May-Thurner syndrome.•The left common iliac vein was compressed by the right common iliac artery.•The left S1 nerve root was compressed by enlarged veins.•May-Thurner syndrome can cause sciatic neuralgia and is curable.