Primary Intraosseous Malignant Nerve Sheath Tumor Of Humerus Presenting With Pathological Fracture: A Rare Case Report With Review Of Literature.

Introduction: Malignant peripheral nerve sheath tumors (MPNST) are rare, aggressive soft-tissue sarcomas arising from peripheral nerves, usually associated with neurofibromatosis Type-I. Intraosseous MPNSTs are exceedingly uncommon and are typically located in the maxillofacial region. There are only 45 documented cases of intraosseous MPNSTs outside the head and neck region, of which only two are of humeral origin and only one reported as pathological fracture. Case Report: We present a rare case of a de novo MPNST of the humerus that presented with pathological fracture and radial nerve palsy. The patient was initially managed with intercalary wide resection, but developed recurrence within 3 months, which was subsequently managed by shoulder disarticulation. The patient remained asymptomatic till 12-month follow-up, when he was found to have lung metastasis and eventually succumbed to the disease. Conclusion: This report adds to the handful of cases of primary MPNST of bony origin, the understanding of which would reduce the possibilities of delayed/missed diagnosis. These tumors are highly aggressive and require prompt detection and multidisciplinary treatment for improved patient outcomes.