A 58-year-old woman with newly diagnosed multiple myeloma (IgG-κ type, 35% bone marrow plasma cells) is being staged. Which investigation is most appropriate to assess for extramedullary disease and spinal involvement?
A. PET-CT with fluorodeoxyglucose
B. Skeletal survey radiography
C. Whole-body low-dose CT (WBLD-CT)
D. Bone marrow biopsy from iliac crest
Explanation
Staging Investigation for Multiple Myeloma: Detecting Extramedullary Disease
Key Point
Whole-body low-dose CT (WBLD-CT) is the current standard imaging modality for staging multiple myeloma, superior to skeletal survey for detecting lytic lesions, extramedullary disease, and soft-tissue involvement.
Evolution of Myeloma Imaging
Table
Modality
Sensitivity for Lytic Lesions
Detects Extramedullary Disease
Detects Spinal Involvement
Current Role
Skeletal survey
~60–70%
Poor
Moderate
Outdated; replaced by WBLD-CT
WBLD-CT
>90%
Excellent
Excellent
Standard for staging
MRI (whole-spine)
Excellent
Good
Excellent
For spinal cord compression assessment
PET-CT
High specificity
Good
Good
Prognostic; not routine staging
High-YieldNEET PG
WBLD-CT detects lytic lesions in 90% of myeloma patients, compared to 60% with skeletal survey. It is now the recommended first-line imaging for staging per IMWG and NCCN guidelines.
Clinical Pearl
MRI of the spine is reserved for patients with neurologic symptoms (spinal cord compression, radiculopathy) or when WBLD-CT shows spinal lesions requiring further characterization.
Warning
Skeletal survey is now considered outdated for myeloma staging; many centers have abandoned it in favor of WBLD-CT, though it may still be used in resource-limited settings.
