Context: Solitary bone plasmacytoma (SBP) are rare lesions, accounting for less than 5% of all plasma cell proliferations. We describe a case of a 21-year-old female with Trisomy 21 presenting with cauda equina compression from an SBP. Findings: Solitary bone plasmacytoma (SBP) is a rare primary bone tumor. It is characterized by monoclonal proliferation of malignant plasma cells localized to a bone segment, without signs of systemic invasion. The vertebral location is the most common. It preferentially affects men during their 5th or 6th decade. Clinical relevance: We report the first association between solitary bone plasmacytoma and Trisomy 21.
Keywords: Cauda equina syndrome; Extramedullary plasmacytoma; Plasmacytoma; Solitary bone plasmacytoma; Trisomy 21.