What diagnostic tests to order for a patient with suspected multiple myeloma?

From the Guidelines

For a patient with suspected multiple myeloma, I recommend ordering a comprehensive diagnostic workup including complete blood count with differential, comprehensive metabolic panel, serum protein electrophoresis with immunofixation, serum free light chain assay, beta-2 microglobulin, lactate dehydrogenase, and 24-hour urine protein electrophoresis, as outlined in the most recent guidelines 1.

Diagnostic Tests

The initial diagnostic workup should include:

• Complete blood count (CBC) with differential and platelet counts
• Blood urea nitrogen (BUN), serum creatinine, and serum electrolytes
• Serum calcium, albumin, and lactate dehydrogenase (LDH)
• Beta-2 microglobulin
• Serum protein electrophoresis (SPEP) with immunofixation
• Serum free light chain (FLC) assay
• 24-hour urine protein electrophoresis

Imaging Studies

Imaging studies should include:

• Full skeleton radiographic survey or whole-body, low-dose CT scan to detect bone lesions
• Magnetic resonance imaging (MRI) or computed tomography (CT) scan may be needed to evaluate symptomatic bony sites

Bone Marrow Evaluation

Bone marrow aspiration and biopsy are essential for definitive diagnosis, with:

• Flow cytometry
• Cytogenetics
• Fluorescence in situ hybridization (FISH) analysis to assess plasma cell percentage and genetic abnormalities

Additional Tests

Additional tests should include:

• Serum calcium, albumin, and creatinine to assess for end-organ damage These tests help identify the hallmarks of multiple myeloma: monoclonal protein in serum or urine, clonal plasma cells in bone marrow exceeding 10%, and myeloma-defining events such as hypercalcemia, renal insufficiency, anemia, or bone lesions (CRAB features) 1. Early detection through this comprehensive workup allows for timely intervention, potentially preventing serious complications like pathologic fractures, renal failure, and hyperviscosity syndrome.

From the Research

Diagnostic Tests for Multiple Myeloma

To diagnose multiple myeloma, the following tests should be ordered:

• Complete blood count with differential 2, 3
• Serum chemistries 2, 3
• Creatinine, lactate dehydrogenase, and beta2-microglobulin tests 2, 3
• Immunoglobulin studies 2, 3
• Serum protein electrophoresis with immunofixation 4, 3
• 24-hour urine protein electrophoresis 4
• Full-body skeletal imaging with:
  • Computed tomography 4, 5
  • Positron emission tomography 4, 5
  • Magnetic resonance imaging 4, 5
• Bone marrow evaluation 2, 3

Additional Tests

Additional tests that may be useful in the diagnosis and staging of multiple myeloma include:

• Fluorescence in situ hybridization (FISH) to detect genetic abnormalities such as del(17p), t(4;14), and t(14;16) 6, 4
• Measurement of serum free light chain levels 6, 4
• Skeletal survey to evaluate for lytic lesions, vertebral compression fractures, and osteoporosis 3