RESUMEN
BACKGROUND: Amyloidosis is a clinical picture brought on by extracellular deposits of insoluble, non-degradable proteins. The clinical presentation of amyloidosis depends upon the type of protein and the organ afflicted. CASE DESCRIPTION: A 65-year-old woman had stiffness of the locomotor apparatus, recurrent carpal tunnel syndrome and problems with swallowing. Laboratory and urine investigations initially showed no abnormalities, but histopathological investigation of a synovial biopsy revealed amyloidosis with light-chain deposits. This turned out to be due to multiple myeloma. CONCLUSION: Amyloidosis can present with atypical symptoms, such as stiffness. Normal erythrocyte sedimentation rate (ESR) and normal urine analysis do not exclude this diagnosis. When there are clinical indications of amyloidosis further analysis for free-light chains should be performed, even when ESR is normal.