Sarcoid Neuropathy Presenting with Two Novel Ultrasound Findings of Increased Intraneural Blood Flow and Small Saphenous Vein Wall Thickening

Diagnosing sarcoid neuropathy (SN) can be difficult because of its nonspecific symptoms and requirement for histological confirmation. We herein report a 71-year-old woman who presented with distal muscle weakness and paresthesia. Nerve conduction studies support the existence of polyneuropathy. Nerve ultrasonography revealed enlargement of the sural nerve and loss of the normal "honeycomb" appearance. In addition, increased intraneural blood flow within the nerve and small saphenous vein wall thickening were observed. These ultrasound findings led to a successful nerve biopsy confirming SN. Steroid therapy has resulted in clinical and ultrasonographic improvements. These results suggest the potential utility of ultrasound for diagnosing and monitoring SN.