Permanent Motor Function Loss by Delayed Treatment of Peroneal Intraneural Ganglion.

: The low incidence of intraneural ganglion makes it difficult to diagnose and treat before it becomes serious nerve damage. This case describes a 69-year-old female, who suffered from the right drop foot and was diagnosed as a peroneal intraneural ganglion. Resection of the mass relieved the pain; however, motor function was not recovered. Early diagnosis and nerve decompression are essential for the peroneal intraneural ganglion before critical nerve symptoms.