A posterior tibial nerve neurilemoma unrecognized for 10 years: Case report

OBJECTIVE AND IMPORTANCE: Neoplasms of peripheral nerves can be obscured, e specially during the early phase. The author reports a patient with a poste rior tibial nerve neurilemoma (schwannoma). For a decade, the tumor was mis diagnosed as nonspecific S1 radiculopathy and psychogenic chronic pain synd rome. The patient's presentation and initial management are unique. CLINICAL PRESENTATION: A 40-year-old woman reported severe left foot and ca lf pain, numbness, and weakness. The symptoms were evident during three pre gnancies, and they gradually progressed. The neuropathic pain was protracte d, despite implantation of a dorsal column stimulator and administration of a wide variety of medications and therapies. The symptoms were unresponsiv e to both inpatient and outpatient treatments, which resulted in a misdiagn osis of psychogenic pain for more than a decade. Diagnostic scans obtained by computed tomography, ultrasonography, and nuclear scintigraphy confirmed a popliteal fossa mass. INTERVENTION: A high, large posterior tibial nerve neurilemoma was found in traoperatively, positioned just below the sciatic nerve bifurcation with ex tensive degenerative features and hemorrhages. Surgical resection provided immediate recovery. CONCLUSION: Peripheral nerve tumors are rarely acknowledged clinical entiti es. Chronic unexplained foot and calf pain and a positive Tinel's sign shou ld raise suspicion of posterior tibial nerve neurilemoma. Even in patients who have had such tumors for a decade, surgical resection remains the treat ment of choice.