Double Trouble: Rare Multiple Femoral Nerve Schwannomma and Peripheral Neuropathy Respond to Immunosuppression in a Patient with Neurofibromatosis Type 2
Lydia Kauffman1, Sarah Mauney1, Max Lowden2, James Grogan3, Julie Fanburg-Smith1, Kimberly Harbough1
1Penn State Milton S. Hershey Medical Center, 2Penn State Hershey Medical Center, 3Pennsylvania State University Hershey Medical Center
Objective:
To highlight a rare case of femoral peripheral nerve sheath tumor and peripheral neuropathy responding to immunosuppression in a patient with neurofibromatosis type 2.
Background:
Neurofibromatosis 2 (NF2), is a predominantly autosomal dominant disorder leading to development of dysfunction at a cellular level associated with nervous system tumors, ophthalmological and cutaneous lesions, and peripheral neuropathy not associated with tumors. Instances of extensive femoral nerve sheath schwannomas in addition to immunosuppression-responsive polyneuropathy have not been reported in the literature.
Design/Methods:
We describe a 52 year-old female with NF2, history of multiple intracranial meningiomas, neurofibromas of both brachial plexuses, and bilateral acoustic neuromas who presented with progressive left leg numbness, lower extremity weakness, and left leg edema and skin discoloration. MRI ofthe left thigh showed two masses following the left femoral nerve distribution as well as a left sciatic schwannoma. EMG/NCS demonstrated a chronic, severe, mixed but primarily axonal sensorimotor polyneuropathy. The femoral nerve sheath tumor was resected, and histology demonstrated hybrid neurofibroma-schwannoma characteristics. For the demyelinating polyneuropathy she was treated with prednisone with improvement followed by IVIg which did not provide benefit. She was then started on mycophenolate mofetil with significant improvement in her weakness.
Conclusions:
Schwannomas are tumors originating from the nerve sheath tissue and most commonly involve the upper extremities. Peripheral schwannoma involving the femoral nerve are rare. In addition, this case highlights a chronic demyelinating polyneuropathy in a patient with NF2 that has not yet been reported in the literature despite reports of up to 66% of NF2 patients with peripheral nerve symptoms in the absence of a compressive lesion.