Primary malignant tumors of the brachial plexus are rarely encountered compared to the benign pathologies of the region. In this report, we present a case with a primary malignant tumor of the brachial plexus which presented difficulties in making differential diagnosis between malignant peripheral nerve sheath tumor and synovial sarcoma based on its pathology, and operated with a suggestive diagnosis of a schwannoma. The diagnostic tests, surgical approach and treatment modalities were discussed in the light of current literature.

Keywords: Brachial plexus, malignant peripheral nerve sheath tumor, synovial sarcoma