Table 4 - Solitary Plasmacytoma of Bone Diagnostic Criteria: All Three Required 1. Biopsy-proven monoclonal plasmacytoma of bone in a single site only. X-rays and MRI and/or FDG PET imaging (if performed) must be negative outside the primary site. The primary lesion may be associated with a lowa serum and/or urine M-component 2. The bone marrow contains < 10% monoclonal plasma cells 3. No other myeloma-related organ dysfunction a Low is defined as: serum IgG < 3.5 g/dl; serum IgA < 2.0 g/dl; urine monoclonal kappa or lambda < 1.0 g/24h.