Shoulder Pad Sign: A Rare Manifestation of Amyloidosis

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bstract

Amyloidosis is a clinical disorder caused by the extracellular deposition of insoluble amyloid fibrils that alter the normal function of tissue. Immunoglobulin amyloidosis is a well-recognized cause of macroglossia and shoulder pad sign. The shoulder pad sign is the prominent appearance of the bilateral anterior deltoid area due to amyloid deposition, particularly the kappa light chain, in periarticular soft tissue. A 65-year-old male presented with gradually progressive bilateral shoulder joint swelling for 10 years, bilateral knee joint swelling for the last five years, and bilateral swelling of lower limbs for 15 days. Biopsy of abdominal fat shows apple-green birefringence on Congo red staining and that from tongue tissue shows features suggestive of amyloidosis. The patient was managed conservatively with diuretics, steroids, and oral melphalan.