Role of Intraoperative Nerve Stimulator? In a Case of Ulnar Nerve Schwannoma. A Case Report with Four-Year Follow-up and Review of Literature

Original Article | Volume 6 | Issue 3 | JBST September – December 2020 | Page 13-15 | Kalaivanan Kanniyan, Ying Lee Lam, Ho Wai Yip Kenneth, Yau Raymond DOI: 10.13107/jbst.2020.v06i03.33

Author: Kalaivanan Kanniyan[1],[2], Ying Lee Lam[1], Ho Wai Yip Kenneth[1], Yau Raymond[1]

[1]Department of Orthopaedic Oncology, Queen Mary Hospital, University of Hong Kong, Hong Kong,
[2]Department of Arthroplasty and Oncology, Asian Joint Reconstruction Institute – AJRI at SIMS Hospitals, Chennai, Tamil Nadu, India.

Address of Correspondence
Dr. Kalaivanan Kanniyan,
Division of General Orthopaedics and Oncology, Queen Mary Hospital, University of Hong Kong, Hong Kong.

Introduction: Schwannoma (neurolimmea) is an uncommon benign nerve sheath tumor arising from the peripheral nerve system with an incidence of 5%. They are slow growing tumors affecting all age group and occur in isolation. They are common in upper extremity followed by the lower extremity.
Case report: She presented with complaint of pain and swelling over her right wrist disturbing her daily activities such as eating and holding her walker. The swelling was sudden on onset slowly progressive in nature over many years. She was on treatment for diabetes mellitus, hypertension, and Parkinson. She had left leg weakness due to polio and hence walker bound. She underwent occipitocervical fusion for cervical vertebrae C1 and C2 subluxation and cervical myelopathy. The swelling was 2.5 cm × 2.5 cm, soft-tissue mass over the volar aspect of right wrist mobile only in the longitudinal direction. Hand grip was fair with sensory loss along the ulnar nerve distribution. There was no hypothenar muscle wasting. Magnetic resonance imaging suggested of neurogenic tumor of ulnar nerve origin. Patient was planned for enucleation (excision biopsy). The anesthesia nerve block device was used as nerve stimulator to identify the motor nerve and preserved it. Enucleation was not possible and hence the tumor was removed with a segment of sensory fibers. Histology finding was consistent with schwannoma. Postoperatively, the patient was pain free and able to hold the walker and carry on her daily activities. At 4 year follow-up the patient had no recurrence of such tumor or any other complication in the operated side.
Conclusion: Enucleation is the treatment of choice. Patient age, complaints, comorbidities, functional demand, tumor location, and intraoperative findings with nerve stimulator help in deciding the choice of nerve grafting along with enucleation.
Keywords: Schwannoma, ulnar nerve, enucleation, sural nerve graft, intraoperative nerve stimulator.

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How to Cite this article: Kanniyan K, Lam YL, Kenneth HWY, Raymond Y | Role of Intraoperative Nerve Stimulator? In a Case of Ulnar Nerve Schwannoma. A Case Report with Four-Year Follow-up and Review of Literature | Journal of Bone and Soft Tissue Tumors | Sep-Dec 2020; 6(3): 13-15.

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