Schwannomas, known also as neurilemmomas, are considered to be benign in the vast majority of cases. Originating from the schwan cells of the neural sheath of peripheral nerves, they usually develop in the head and neck. Involvement of the brachial plexus is relatively rare, with an incidence of 0.3–0.4/100,000 person per year1. Malignant transformation is extremely uncommon. Patients’ initial symptoms include pain, loss of function, numbness or a progressively growing mass in the supraclavicular region. Neglected cases regarding larger benign tumors may present with monoparesis of an upper limb2. Primary malignant schwannomas of the brachial plexus causing monoplegia are extremely infrequent and to the best of our knowledge very few cases have been published in the international literature.