Spinal Solitary Plasmacytoma With Minimal Marrow Involvement Presenting With Epidural Spinal Cord Compression

Solitary plasmacytoma (SPC) is a rare type of plasma cell dyscrasia characterized by the proliferation of neoplastic monoclonal plasma cells. It can involve bone or soft tissue without signs of systemic disease. The solitary bone plasmacytoma typically involves the axial skeleton, most commonly the vertebrae. This article presents a 58-year-old male with a history of Parkinson's disease, hypertension, and cervical spine degenerative joint disease. He arrived at the emergency department with severe thoracic and lumbar back pain, accompanied by numbness and weakness in both legs, which worsened with movement and deep breathing. Magnetic resonance imaging (MRI) findings revealed a sizable mass in the T11 vertebra, leading to thoracic spinal cord compression. Treatment included high-dose dexamethasone, and surgical intervention was undertaken. Subsequent pathology confirmed plasma cell dyscrasia. Radiotherapy and chemotherapy (lenalidomide and dexamethasone) were administered, resulting in no recurrence or new masses after two years. Solitary plasmacytoma is a rare disease with limited clinical trials due to the inability to accrue larger cohorts. Prompt diagnosis and staging of plasmacytomas, involving robust histopathological and radiographic methods, are needed to prevent further complications and possible progression to multiple myeloma. Radiation therapy is the primary treatment, with some studies showing the benefits of lenalidomide and dexamethasone. Further studies are needed to improve treatment options for these patients. This case report adds to the current literature the importance of a multidisciplinary approach to the treatment of SPC.