Recurred Segmental Schwannomatosis Without Neurofibromatosis Type 2

Abstract

Schwannomas are the most common type of benign peripheral nerve sheath tumors. They typically present as a solitary lesion, but multiple schwannomas rarely occur in patients with neurofibromatosis type 2 (NF2), or patients without the other hallmarks of NF2. The latter is termed schwannomatosis. They most commonly occur in the head and neck involving the brachial plexus and spinal nerves. Although rarely found in the extremities, when these masses occur peripherally, they most commonly affect the sciatic, ulnar, and tibial nerve. It is reported that 2.4% to 5% of all patients undergoing schwannoma excision present as schwannomatosis. One-third of patients with schwannomatosis show tumors limited to a single extremity or segment of the spine and it is referred to as segmental schwannomatosis. We report a case of recurred segmental schwannomatosis of the posterior tibial nerve without features of NF2 after schwannoma excision.