Multiple Myeloma Diagnostic Criteria (CRAB + SLiM-CRAB)
IMWG 2014 diagnostic criteria for multiple myeloma. Clonal bone marrow plasma cells >= 10% PLUS CRAB features (hyperCalcaemia, Renal failure, Anaemia, Bone lesions) OR biomarkers defining malignancy (SLiM criteria).
Score interpretation
CRAB and SLiM criteria not met -- myeloma diagnosis not established
→ If BMPC 10-59% without CRAB/SLiM: diagnose Smouldering Multiple Myeloma (SMM); assess 20-2-20 criteria; intermediate/high-risk SMM: consider daratumumab monotherapy (AQUILA trial) or clinical trial; observation (watch and wait) for low-risk SMM; re-biopsy if progression; serum and urine protein electrophoresis quarterly; FLC ratio quarterly; LDH, beta-2 microglobulin; PET-CT or whole-body MRI to assess for subclinical bone lesions; haematology specialist follow-up.
IMWG myeloma criteria fulfilled -- treatment required
→ Confirmed multiple myeloma: staging (R-ISS using ISS, LDH, FISH); FISH cytogenetics: t(4;14), t(14;16), del(17p), del(1p), amp(1q) -- high-risk cytogenetics affect treatment selection and prognosis; CRAB management: hypercalcaemia -- IV fluids + bisphosphonate + steroids; renal failure -- IV fluids, avoid nephrotoxins, dialysis if needed; anaemia -- EPO + iron or transfusion; bone lesions -- bisphosphonate (zoledronic acid 4 mg IV monthly) + orthopaedic referral for pathological fractures; treatment: transplant-eligible: VRd (bortezomib + lenalidomide + dexamethasone) induction x4 cycles then ASCT (DETERMINATION trial); transplant-ineligible: VRd x9 cycles or Dara-VMP; add daratumumab to all lines (CASSIOPEIA, MAIA, ALCYONE trials); maintenance: lenalidomide post-transplant (IFM 2005-02, CALGB 100104); bone protection: zoledronic acid or denosumab for 2 years.
Interpretation bands for the Myeloma Diagnostic CRAB. Apply clinical judgement and local guidance.
References
- Rajkumar SV et al. International Myeloma Working Group updated criteria for the diagnosis of multiple myeloma. Lancet Oncol. 2014;15(12):e538-548.
- NICE NG35. Myeloma: diagnosis and management. NICE. 2016 (updated 2022).
Related
Curated clinical cross-links plus same-class fallbacks.
- Gelatin (succinylated) · Colloid plasma volume expander
- Lanadelumab · Anti-plasma kallikrein monoclonal antibody
- Sodium Cromoglicate Nasal Spray · Mast Cell Stabiliser — Allergic Rhinitis
- Olopatadine · H1 antihistamine + mast cell stabiliser
- C1-esterase inhibitor · Plasma-derived complement inhibitor
- Berotralstat · Oral plasma kallikrein inhibitor
- Major Haemorrhage / Massive Transfusion · BCSH; RCOA; RCEM; RCS — BCSH Guidelines
- Anaemia Investigation · BSH / NICE
- Splenomegaly Workup · BSH; BMJ Best Practice
- Deep Vein Thrombosis Diagnosis and Treatment · NICE CG144 / NICE NG158
- Sickle Cell Crisis · BSH 2021 / BCSH
- Neutropenic Sepsis · NICE CG151 2012 / ESMO
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.