Intracapsular Micro-Enucleation of a Painful Superficial Peroneal Nerve Schwannoma in a 60-Year Old Man: A Rare Encounter.

BACKGROUND Schwannomas are the most common benign peripheral nerve sheath tumors, localized mainly to the cranial and upper extremity nerves. Their occurrence in the lower limbs is uncommon, and specific involvement of the superficial peroneal nerve is exceedingly rare. We report a case of a painful right superficial peroneal nerve schwannoma that was excised via the intracapsular micro-enucleation technique. CASE REPORT A 60-year-old South Asian man presented with a 2-year history of a painful lump on the lateral aspect of the right upper leg. Clinical examination revealed a firm mass located at the proximal lateral aspect of the right leg, measuring approximately 3×2.5 cm. Severe tenderness over the mass was present. The Tinel test was positive. There were no sensory or motor deficits or history of neurofibromatosis. Imaging showed features suggestive of a schwannoma. Surgery was indicated; intracapsular micro-enucleation was performed. Histopathological assessment of the tumor demonstrated Antoni A and B patterns with nuclear palisading and Verocay bodies, hallmarks of a schwannoma. The postoperative period was uneventful; no neurological deficits were noted. CONCLUSIONS The case described is considered rare, with no data on disease epidemiology in the literature. We provide a brief review and add pivotal data to the literature. Despite its rarity, one should remain cognizant of the condition and consider it in the differential diagnosis of nontraumatic leg pain. Based on our experience, corroboration from previous case reports, and the satisfactory outcome of our case, we advocate the intracapsular micro-enucleation technique when possible for schwannomas.