Multiple Myeloma: Role of Imaging in Diagnosis, Staging, and Treatment Response Assessment

The importance of bone marrow infiltration patterns in multiple myeloma seen on magnetic resonance imaging-Case report and imaging perspective

Non-secretory multiple myeloma (NSMM) is an extremely rare variant of multiple myeloma (MM) and accounts for a maximum of 5% of all myeloma cases. This variant of MM usually represents a diagnostic challenge to the clinician because of the absence of detectable monoclonal immunoglobulin on serum or urine electrophoresis. We present the case of a 34-year-old Caucasian male who presented to the emergency department with pain in the lumbar area secondary to a fall and who was eventually diagnosed with non-secretory multiple myeloma after the radiologist initially pointed out a discrete "salt and pepper" infiltration of the spine seen on magnetic resonance imaging (MRI) although the spine computed tomography (CT) performed initially showed no suspicious lesions for malignancy. The final diagnosis was obtained after a positive bone marrow biopsy together with the presence of malignant lesions seen on the spine MRI. This case points out the importance of different bone marrow involvement patterns seen on MRI and other useful sequences the radiologist could use to better discriminate between normal marrow reconversion and malignant infiltration.

Infiltration of the spinal cord and peripheral nerves in multiple myeloma

Background

Multiple myeloma (MM) is a hematological malignancy, and intramedullary spinal cord metastasis is extremely rare.

Methods

Clinical and radiological data were collected from electronic medical records as well as a literature review of reported cases.

Results

We report a rare case of IgA-LAM stage IIB MM with involvement of the spinal cord and peripheral nervous system. Laboratory studies showed elevated levels of serum β2-macroglobulin and cerebrospinal fluid protein. Electromyography revealed a demyelinating process with motor conduction blocks. On MRI, the lesions of MM bone marrow are characterized as a type of diffuse infiltration. MR neurography demonstrated an enhanced nodule in the thoracic segment with swelling of the cervicothoracic segments of the spinal cord. Moreover, swelling and hypertrophy of the entire nerve branchial, lumbosacral plexus, and cauda equina were detected, accompanied by myofascitis and denervated muscles. Ultimately, the condition of the patient deteriorated quickly and she died with a diagnosis of refractory MM.

Conclusion

MRI not only has the advantage of displaying the primary involved site of the bone marrow but also facilitates detecting extramedullary hematopoietic MM, such as infiltrating sites of the central and/or peripheral nervous system.

Myeloma Spine and Bone Damage Score (MSBDS) on Whole-Body Computed Tomography (WBCT): Multiple Reader Agreement in a Multicenter Reliability Study

Objective: To assess the reliability of the myeloma spine and bone damage score (MSBDS) across multiple readers with different levels of expertise and from different institutions. Methods: A reliability exercise, including 104 data sets of static images and complete CT examinations of patients affected by multiple myeloma (MM), was performed. A complementary imaging atlas provided detailed examples of the MSBDS scores, including low-risk and high-risk lesions. A total of 15 readers testing the MSBDS were evaluated. ICC estimates and their 95% confidence intervals were calculated based on mean rating (k = 15), absolute agreement, a two-way random-effects model and Cronbach’s alpha. Results: Overall, the ICC correlation coefficient was 0.87 (95% confidence interval: 0.79–0.92), and the Cronbach’s alpha was 0.93 (95% confidence interval: 0.94–0.97). Global inter- and intra-observer agreement among the 15 readers with scores below or equal to 6 points and scores above 6 points were 0.81 (95% C.I.: 0.72–0.86) and 0.94 (95% C.I.:0.91–0.98), respectively. Conclusion: We present a consensus-based semiquantitative scoring systems for CT in MM with a complementary CT imaging atlas including detailed examples of relevant scoring techniques. We found substantial agreement among readers with different levels of experience, thereby supporting the role of the MSBDS for possible large-scale applications. Significance and Innovations • Based on previous work and definitions of the MSBDS, we present real-life reliability data for quantitative bone damage assessment in multiple myeloma (MM) patients on CT. • In this study, reliability for the MSBDS, which was tested on 15 readers with different levels of expertise and from different institutions, was shown to be moderate to excellent. • The complementary CT imaging atlas is expected to enhance unified interpretations of the MSBDS between different professionals dealing with MM patients in their routine clinical practice.