High Resolution Ultrasonography of Ganglion in the Left Common Peroneal Nerve

Intraneural ganglion is uncommon. We report a 49-year-old man with numbness of the left lower leg and foot drop for 1 month. High resolution ultrasonography (HRUS) showed a fusiform hypoechoic cystic structure, 5 × 0.5 cm in size, in the left lateral popliteal fossa which extended to below the fibula head region and which was encased by the epineurium of the left common peroneal nerve. Histology was compatible with ganglion. After operation, the patient recovered very well. This was correlated to a previous report in which the outcome essentially depended on the resectability of the lesion without nerve damage and the duration of symptoms. HRUS has the advantage of no radiation exposure, good resolution and high mobility. HRUS could be a valuable screening tool for soft tissue neoplasm and to differentiate it from the surrounding structure.