The International Myeloma Working Group (IMWG) has reported criteria for the diagnosis of multiple myloma.
Criteria for multiple myeloma - both of the following:
(1) plasma cell proliferation (one of the following):
(1a) clonal bone marrow plasma cells >= 10%
(1b) biopsy-proven bone plasmacytoma
(1c) biopsy-proven extramedullary plasmacytoma
(2) one or more of the following:
(2a) evidence of end-organ damage including CRAB findings attributable to plasma cell proliferation
(2b) clonal bone marrow plasma cell percentage >= 60%
(2c) involved light chain >= 100 mg/L AND involved-to-uninvolved light chain ratio >= 100
(2d) 2 or more focal lesions >= 5 mm in diameter on MRI
CRAB findings:
(1) hypercalcemia (> 11 mg/dL)
(2) renal insufficiency (creatinine clearance < 40 mL per min; serum creatinine > 2 mg/dL)
(3) anemia (hemoglobin < 10 g/dL)
(4) >= 1 osteolytic bone lesions on CT or CT-PET
