What are the essential components of a myeloma screen to rule out multiple myeloma?

Essential Components of a Myeloma Screen

A comprehensive myeloma screen must include serum and urine protein studies, complete blood count, chemistry panel, bone marrow examination, and skeletal imaging to effectively rule out multiple myeloma. 1

Blood Tests (Laboratory Assessment)

Serum Protein Studies

• Serum protein electrophoresis (SPEP) - Detects and quantifies monoclonal protein (M-protein) 1, 2
• Serum immunofixation electrophoresis (SIFE) - Characterizes heavy and light chains of the M-protein 1, 2
• Serum free light chain (FLC) assay - Measures kappa and lambda free light chains and their ratio 1, 2
• Quantitative immunoglobulins - Measures IgG, IgA, and IgM levels by nephelometry 1, 2

Complete Blood Count and Chemistry

• Complete blood count with differential - Evaluates for anemia and examines peripheral blood smear for rouleaux formation 1
• Serum calcium - Assesses for hypercalcemia (part of CRAB criteria) 1
• Serum creatinine - Evaluates renal function (part of CRAB criteria) 1
• Serum albumin - Important for staging and prognosis 1
• Serum β2-microglobulin - Critical for staging and prognosis 1, 2
• Lactate dehydrogenase (LDH) - Provides prognostic information 1, 2

Urine Studies

• 24-hour urine collection - For total protein quantification 1
• Urine protein electrophoresis (UPEP) - Detects and quantifies urinary M-protein 1
• Urine immunofixation electrophoresis (UIFE) - Confirms presence and type of urinary M-protein 1

Bone Marrow Assessment

• Bone marrow aspirate and biopsy - Evaluates plasma cell percentage and morphology 1
• Immunohistochemistry - Confirms clonality of plasma cells 1
• Cytogenetics - Standard metaphase karyotyping 1
• Fluorescence in situ hybridization (FISH) - Detects specific genetic abnormalities, especially chromosome 17p13, t(4;14), and t(14;16) 1, 2

Imaging Studies

• Skeletal survey - X-rays of spine, pelvis, skull, humeri, and femurs to detect lytic bone lesions 1
• Advanced imaging - MRI, CT, or PET/CT as clinically indicated, especially when skeletal survey is negative but bone lesions are suspected 1, 3

Critical Pitfalls to Avoid

1. Failing to perform immunofixation when protein electrophoresis is negative - approximately 3% of multiple myeloma patients have non-secretory disease 2

2. Using random urine samples instead of 24-hour urine collection - can lead to inaccurate results and missed diagnosis 1, 2

3. Incomplete cytogenetic evaluation - impacts prognosis and treatment decisions 1, 2

4. Not measuring serum free light chains - essential for detecting light chain abnormalities and monitoring non-secretory myeloma 2, 4

5. Relying solely on serum studies without urine assessment - can miss light chain myeloma 1

6. Inadequate bone marrow sampling - both aspirate and biopsy should be considered to accurately assess plasma cell infiltration 1

7. Limited skeletal imaging - inadequate imaging can miss bone lesions, leading to misdiagnosis of smoldering myeloma instead of symptomatic disease 1

Diagnostic Criteria Application

The comprehensive myeloma screen helps differentiate between:

• Multiple myeloma - ≥10% clonal plasma cells in bone marrow or biopsy-proven plasmacytoma, plus evidence of end-organ damage (CRAB criteria) 1
• Smoldering multiple myeloma - ≥3 g/dL serum M-protein and/or ≥10% clonal plasma cells, without end-organ damage 1
• Monoclonal gammopathy of undetermined significance (MGUS) - <3 g/dL serum M-protein, <10% clonal plasma cells, no end-organ damage 1

By systematically performing these essential components of the myeloma screen, clinicians can effectively rule out multiple myeloma or accurately diagnose and stage the disease if present.