Abstract
Solitary plasmacytoma (SP) can be classified into two groups: a solid mass of neoplastic monoclonal plasma cells in bone, also called a solitary bone plasmacytoma (SBP), or less likely solitary extramedullary plasmacytoma (SEP) without any evidence of systemic disease of multiple myeloma. The diagnosis should be made by biopsy confirmation, revealing monoclonal plasma cell infiltration from the mass. The SBP usually affects the axial skeleton. Males have a higher incidence than females, as the ratio is 2/1, and the average age is 55. SP incidence usually increases with age. SBP has a significantly higher risk for progression to myeloma, usually within two years, and radiotherapy (RT) is the treatment of choice. Patients with acute declining neurologic dysfunction require urgent surgery before radiation therapy. We report a middle-aged man who presented with bilateral lower extremity weakness. Thoracic MRI with and without contrast revealed a large soft tissue and osseous mass centered at the T8 vertebral body with a large paravertebral extension, causing spinal cord compression at the T8-T9 level. The patient's clinical presentation, assessment, and rehabilitation management are discussed. Patients with this diagnosis are not properly diagnosed for approximately six months.