Development of hypercalcemia (corrected serum calcium >11.5 mg/dl or 2.65 mmol/l) that can be attributed solely to the plasma cell proliferative disorder IMWG Criteria for Diagnosis of Multiple Myeloma Presence of an M-component in serum and/or urine plus clonal plasma cells in the bone marrow and/or a documented clonal plasmacytoma. In patients with no detectable M-component, an abnormal serum FLC ratio on the serum FLC assay can substitute and satisfy this criterion. For patients, with no serum or urine M-component and normal serum FLC ratio, the baseline bone marrow must have ≥10% clonal plasma cells; these patients are referred to as having 'non-secretory myeloma'. Patients with biopsy-proven amyloidosis and/or systemic light chain deposition disease (LCDD) should be classified as 'myeloma with documented amyloidosis' or 'myeloma with documented LCDD,' respectively if they have ≥30% plasma cells and/or myeloma-related bone disease.