An unusual cause of tarsal tunnel syndrome: Schwannoma of the posterior tibial nerve; a rare cause and rare localization

INTRODUCTION: Schwannoma of the posterior tibial nerve is extremely rare. CASE PRESENTATION: A 25-year-old female with a one-year history of left foot pain is presented. Clinical and radiological findings were in favor of a tarsal tunnel syndrome caused by a schwannoma of the posterior tibial nerve, prompting the patient to undergo surgery. We performed a complete excision of the tumor with the aid of a loupe magnification. At the last follow-up, the patient did well, with no recurrent pain and no neurological squeals. DISCUSSION: The diagnosis of a tibial nerve schwannoma can often be difficult as, in the early stages, a mass may not be palpable and symptoms are often non-specific because of the slow-growing soft tissue mass. CONCLUSION: Although schwannoma is a rare cause of tarsal tunnel syndrome, it should be kept in mind by physicians, especially in cases of chronic unexplained foot pain with a positive Tinel's test.