Multiple myeloma is a malignancy characterized by the clonal proliferation of plasma cells. It is a "master of disguise" among tumors and is easily misdiagnosed.Patients may visit orthopedics for bone pain, nephrology for renal dysfunction, or respiratory medicine for infections, leading to a misdiagnosis rate as high as 40%–60%.Its typical symptoms are summarized by the "CRAB" criteria.
Global prevalence of multiple myeloma
Multiple myeloma is most common in middle-aged and elderly individuals, with a median age of onset of 69 years. It has an overall incidence rate of approximately 2 per 100,000 people, making it the second most common hematologic malignancy.As the disease progresses, "CRAB" symptoms may appear: elevated blood calcium (hypercalcemia), renal insufficiency, anemia, and bone disease.Due to the inhibition of normal immunoglobulin production, patients are prone to recurrent infections.
Symptoms associated with multiple myeloma stages
1.Early symptoms of multiple myeloma
During the asymptomatic phase—or when presenting only with mild anemia and proteinuria—symptoms are atypical, making misdiagnosis as other conditions likely.Some patients initially present to the orthopedics department with lower back pain.
2.Symptoms of intermediate-stage multiple myeloma
Typical CRAB symptoms appear: skeletal damage leads to bone pain and pathological fractures; hypercalcemia causes nausea and constipation; renal impairment results in oliguria and edema; and anemia leads to fatigue and dizziness.
3.Symptoms of advanced multiple myeloma
Extensive bone destruction causing multiple pathological fractures and spinal cord compression; renal failure requiring dialysis; recurrent severe infections; hyperviscosity syndrome causing dizziness and confusion.
When to Seek Medical Attention
Early signs of multiple myeloma include persistent bone pain, anemia and fatigue, abnormal renal function, and manifestations of hypercalcemia.Please consult a doctor via the "Chat with Doctor" feature to facilitate early detection.During the online consultation, the doctor will ask about your symptoms and laboratory test results, and guide you through tests such as serum protein electrophoresis and bone marrow examination.
Staging of multiple myeloma
Multiple myeloma: Stage 0
During the asymptomatic phase, there is only mild anemia or proteinuria, serum monoclonal protein levels are low, and there is no evidence of organ damage.
Multiple myeloma: Stage I
Low tumor burden; presentation includes mild bone pain and anemia, with hemoglobin levels exceeding 100 g/L and normal serum calcium levels.
Multiple myeloma: Stage II
Moderate tumor burden; worsening bone pain; signs of significant anemia and hypercalcemia; mild renal impairment.
Multiple myeloma: Stage III
High tumor burden accompanied by extensive bone destruction, severe anemia, hypercalcemia, and renal insufficiency.
Multiple myeloma: Stage IV
Accompanied by severe complications such as recurrent infections, renal failure requiring dialysis, and extensive extramedullary infiltration, leading to systemic physical decline.
Detailed Symptoms of Multiple Myeloma
1.Bone pain and lower back pain
Approximately 75% of patients experience bone pain, most commonly in the lumbosacral region, followed by the thoracic and dorsal regions.The tumor causes osteolytic destruction, making pathological fractures—particularly in the spine and ribs—susceptible to occurring from minor exertion or injury.
2.Anemia and fatigue
Approximately two-thirds of patients develop anemia due to the suppression of hematopoiesis caused by myeloma cell infiltration; symptoms include pallor, fatigue, dizziness, tachycardia, and reduced exercise tolerance.
3.Renal function impairment
Approximately 50% of patients exhibit decreased creatinine clearance, and 20%–40% have renal insufficiency at initial diagnosis.Abnormal proteins and hypercalcemia damage the kidneys; severe cases may progress to uremia requiring dialysis.
4.Hypercalcemia
Approximately 30%–40% of patients develop hypercalcemia—caused by the release of calcium into the bloodstream due to bone destruction—manifesting as thirst, nausea, vomiting, constipation, mental confusion, and polyuria.
5.Recurrent infections
Inhibition of normal immunoglobulin production leads to reduced immunity, increasing susceptibility to bacterial pneumonia, urinary tract infections, and herpes zoster; infection is a major cause of death.
6.Pathological fracture
Bone destruction leads to fractures caused by minor external force;commonly affecting the spine, ribs, and long bones, it can cause severe pain, spinal deformity, and spinal cord compression.
7.Bleeding tendency
Thrombocytopenia and platelet dysfunction lead to an increased tendency to bleed, manifesting as nosebleeds, bleeding gums, and cutaneous purpura.
8.Symptoms of hyperviscosity
High levels of M-protein lead to increased blood viscosity, causing dizziness, blurred vision, tinnitus, and Raynaud's phenomenon; severe cases may result in impaired consciousness.
9.Neurological impairment present
Tumor compression or amyloidosis causes limb numbness, weakness, and pain; spinal fractures compressing the spinal cord can lead to paraplegia and bowel or bladder incontinence.
Conclusion
Multiple myeloma is a malignant tumor known for its ability to mimic other conditions; one should be highly alert to unexplained bone pain, anemia, and renal dysfunction.Novel targeted therapies and immunotherapies have significantly improved patient prognosis.
