Age / Sex : 57 / M

Multiple myeloma

Discussion

Findings:

Radiography and CT show numerous, well-circumscribed, lytic bone lesions as MRI does diffuse pattern of marrow infiltration with multilevel compression fractures.

Differential Diagnosis:  

Diagnosis:  

Multiple myeloma

Discussion:

A plain X-ray skeletal survey is standard for staging and follow-up of bone involvement by multiple myeloma, and a typical skeletal survey consists of the following films: lateral skull, frontal chest film, cervico-thoraco-lumbar spine, shoulders, pelvis, femur.

Almost 80% of patients with multiple myeloma will have radiological evidence of skeletal involvement on the skeletal survey most commonly effecting the following sites: vertebrae in 66%, ribs in 45%, skull in 40%, shoulder in 40%, pelvis in 30%, and long bones in 25%

CT is a sensitive imaging modality in detecting the osteolytic effects of multiple myeloma and has a higher sensitivity than plain radiography at detecting small lytic lesions. CT findings in multiple myeloma consist of punched-out lytic lesions, expansile lesions with soft tissue masses, diffuse osteopenia, fractures, and, rarely, osteosclerosis.

MRI is generally more sensitive in detecting multiple lesions compared to the standard plain film skeletal survey. Infiltration and replacement of bone marrow is exquisitely visualized, and newer scanners are able to perform whole body scans for this purpose which has been shown to be superior to both CT and skeletal surveys. Typical myeloma lesions are marrow based and have low signal intensity on T1-weighted images, and a high signal intensity on T2-weighted sequences and STIR images and generally show enhancement on gadolinium-enhanced images. Four patterns of marrow involvement have been identified. A normal marrow appearance is present at diagnosis in 50–70% of untreated Durie/Salmon stage 1 and in 20% of untreated Durie/Salmon stage 3. Other marrow appearances of untreated disease include a focal pattern, a diffuse pattern and a variegated appearance.

References:

1998. Collins, “Multiple myeloma,” in Imaging in Oncology, J. E. Husband and R. H. Resnik, Eds., vol. 2, 1998.

Lecouvet F, Vande Berg B, Malghem J, Maldague B. Magnetic resonance imaging in multiple myeloma. Semin Musculoskelet Radiol 2001; 5:43-55.

Mahnken AH, Wildberger JE, Gehbauer G, et al. Multidetector CT of the spine in multiple myeloma: comparison with MR imaging and radiography. AJR Am J Roentgenol 2002; 178:1429-1436.

83. M. Herneth, K. Friedrich, C. Weidekamm et al., “Diffusion weighted imaging of bone marrow pathologies,” European Journal of Radiology 2005;55:74-83.