Rapidly Progressive Myopathy: Unveiling Light Chain Amyloidosis as an Initial Manifestation of Multiple Myeloma. A Case Report and Literature Review


P. Kaminskiene, T. Stojkovic, D. Roos-Weil, P. Reimbold, A. Chanut, E. Lacene 5, T. Evangelista

We present the case of a 79-year-old man with rapidly progressive myopathy as the initial manifestation of light chain amyloidosis associated with multiple myeloma. The patient experienced progressive lower limb weakness resulting in difficulty climbing stairs. Ancillary tests revealed slightly elevated serum creatine kinase levels. The electromyogram revealed a diffuse myogenic pattern while muscle MRI indicated fatty replacement of the quadriceps muscles. Muscle biopsy revealed the presence of amyloid deposits in the vessel’s walls. An elevated level of lambda (246 mg/L) light chain was detected. The bone marrow aspiration results were consistent with the diagnosis of multiple myeloma. In conclusion, even if amyloid myopathy is a rare condition, routine screening for amyloid deposits in muscle biopsy is crucial and should be performed systematically. In the present case, it enabled a rapid diagnosis and the beginning of treatment.

Published: 6 June 2024
Journal: Neuromuscular Disorders

Link: doi.org/https://doi.org/10.1016/j.nmd.2024.06.002

The ERNs are co-funded by the
European Union (Health Programme and CEF)

EU Commission

“EURO-NMD is one of the 24 European Reference Networks (ERNs) approved by the ERN Board of Member States. The ERNs are co-funded by the European Union (Health Programme and CEF).
For more information about the ERNs and the EU health strategy,
please visit ec.europa.eu/health/ern