Symptoms of Advanced Multiple Myeloma
Advanced multiple myeloma manifests through the CRAB criteria—hypercalcemia, renal insufficiency, anemia, and bone lesions—which represent end-organ damage from malignant plasma cell proliferation. 1
Core Symptomatic Manifestations
The defining symptoms of advanced (symptomatic) multiple myeloma are captured by the CRAB criteria, which distinguish it from asymptomatic disease:
Bone Involvement (Most Common)
- Lytic bone lesions affecting vertebrae, skull, sternum, ribs, pelvis, and proximal long bones (humeri and femora) 2
- Bone pain is present in the majority of patients, particularly affecting the spine and ribs
- Pathologic fractures occur frequently, with devastating consequences including:
- Vertebral body collapse leading to spinal cord compression
- Femoral fractures causing immobility 2
- Severe osteopenia even without discrete lytic lesions 1
- Bone abnormalities are present in 79% of patients at diagnosis 2
Anemia
- Normochromic, normocytic anemia with hemoglobin ≥2 g/dL below normal or <10 g/dL 1
- Manifests as fatigue (present in 98.8% of patients) 3
- Results from bone marrow infiltration by malignant plasma cells 4
- Present in 73% of patients at diagnosis 4
Renal Insufficiency
- Serum creatinine >1.73 μmol/L (>2 mg/dL) or creatinine clearance <40 mL/min 1, 5
- Acute kidney injury occurs in 19% at presentation 4
- Caused by light chain deposition, hypercalcemia, and dehydration
Hypercalcemia
- Serum calcium >11.5 mg/dL (or >11.0 mg/dL by some criteria) 1
- Results from osteoclast activation and bone destruction
- Presents with confusion, polyuria, constipation, and weakness
Additional Advanced Disease Features
Beyond CRAB criteria, advanced myeloma presents with:
Systemic Symptoms
- Weight loss 6
- Constipation (65.2% prevalence) 3
- Peripheral neuropathy with tingling in hands/feet (53.4%) 3
- Recurrent bacterial infections from immune dysfunction 7
Functional Impairment
- Decreased physical functioning (98.9% of patients) 3
- Cognitive dysfunction (80.2%) 3
- Financial difficulties (78.4%) related to disease burden 3
End-Stage Disease Markers
- Extramedullary dissemination with plasmablasts appearing outside bone marrow 8
- Plasma cell leukemia in terminal stages 8
- Hyperviscosity when monoclonal protein >40 g/L, causing retinal hemorrhages and neurologic symptoms 7
- Amyloidosis in some patients requiring periumbilical fat biopsy 7
Clinical Presentation Patterns
Important caveat: While 45% of high-risk smoldering myeloma patients develop clinically significant end-organ damage at progression, another 24% meet diagnostic criteria through laboratory markers alone (≥60% marrow plasmacytosis or free light chain ratio >100) without overt symptoms 9. This underscores that "advanced" disease by diagnostic criteria may not always correlate with severe symptoms initially.
Distinguishing Advanced from Early Disease
The presence of any CRAB criterion defines symptomatic (advanced) myeloma requiring immediate treatment, distinguishing it from:
- Smoldering myeloma: ≥10% plasma cells or M-protein ≥3 g/dL but no CRAB features 1
- MGUS: <10% plasma cells, M-protein <3 g/dL, and no CRAB features 1
The progression from asymptomatic to symptomatic disease occurs at 10% per year in the first 5 years for smoldering myeloma 1, making vigilant monitoring essential to catch the transition to advanced disease requiring treatment.