title: Tarsal tunnel syndrome secondary to schwannoma of the posterior tibial nerve.
abstract: Schwannoma is a benign tumor that arises from the peripheral nerve sheath. It presents as a discrete, often tender, and palpable nodule associated with neurogenic pain or paresthesia when compressed or traumatized. The growth rate is usually slow, and these lesions seldom exceed 2 cm in diameter. We report the case of a large schwannoma arising from the posterior tibial nerve located in the posterior medial ankle. The core needle biopsy findings were suggestive of a schwannoma, with spindle cells strongly and uniformly immunostaining for S-100 protein. The mass was marginally excised. The surgical specimen consisted of a grossly encapsulated white-yellow mass with irregular contours, measuring 3.7 × 3.5 × 2.7 cm. The cut surface showed areas of pin-point hemorrhage. The patient did not encounter any motor deficits; however, early results showed some subjective numbness. Few reports have been published of schwannomas arising from the tibial nerve. Marginal excision appears to be the recommended therapy for this tumor, without any evidence of recurrence at 9 months of follow-up.
authors: Second Year Resident, Beth Israel Deaconess Medical Center, Boston, MA.
authors: Katrina
authors: K
authors: Hallahan
authors: Third Year Resident, Beth Israel Deaconess Medical Center, Boston, MA.
authors: Jessica
authors: J
authors: Vinokur
authors: Second Year Resident, Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA.
authors: Sarah
authors: S
authors: Demski
authors: Dermatopathologist, Department of Pathology, Beth Israel Deaconess Medical Center, Boston, MA.
authors: Beverly
authors: B
authors: Faulkner-Jones
authors: Chief, Division of Podiatric Surgery, Department of Surgery, Beth Israel Deaconess Medical Center, Boston, MA. Electronic address: jgiurini@bidmc.harvard.edu.
authors: John
authors: J
authors: Giurini
mesh_terms: D000842:Ankle; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018317:Nerve Sheath Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D009442:Neurilemmoma / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D012983:Soft Tissue Neoplasms / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D013641:Tarsal Tunnel Syndrome / Q000209:etiology*; D013979:Tibial Nerve
keywords: 4; ankle; immunostaining; nerve sheath; neurilemmoma; surgery; tumor