title: Diagnosing Light Chain Amyloidosis on Temporal Artery Biopsies for Suspected Giant Cell Arteritis.
abstract: Although still rarely diagnosed, amyloid light chain (AL) amyloidosis is the most common form of systemic amyloidosis. It is characterized by misfolded monoclonal immunoglobulin light chain fragments that accumulate extracellularly as amyloid fibrils, with consequent organ dysfunction. We report 2 such cases where initial symptoms and signs were identical to and mistaken for those of giant cell arteritis, associated with polymyalgia rheumatica. Neither patient responded to high-dose corticosteroids; instead, their temporal artery biopsies revealed amyloid deposits and other investigations confirmed a diagnosis of systemic AL amyloidosis. Review of the literature reveals similar cases of diagnostic confusion spanning 75 years. We have summarized the findings and learning points from cases reported in the past 30 years and highlight the need for increased awareness and investigation of this underrecognized syndrome.
authors.affiliation: Haematology (RG), Severn Deanery, Bristol, United Kingdom; National Amyloidosis Centre (SM, AW), University College London, London, United Kingdom; Departments of Histopathology (PM), Ophthalmology (SW), and Haematology (SM), Royal United Hospital Bath, Bath, United Kingdom.
authors.forename: Rosanna A M
authors.initials: RA
authors.lastname: Ghinai
authors.forename: Shameem
authors.initials: S
authors.lastname: Mahmood
authors.forename: Pinias
authors.initials: P
authors.lastname: Mukonoweshuro
authors.forename: Sally
authors.initials: S
authors.lastname: Webber
authors.forename: Ashutosh D
authors.initials: AD
authors.lastname: Wechalekar
authors.forename: Sally E
authors.initials: SE
authors.lastname: Moore
mesh_terms: D000368:Aged; D000686:Amyloidosis / Q000150:complications / Q000175:diagnosis*; D001706:Biopsy / Q000379:methods*; D003937:Diagnosis, Differential; D013700:Giant Cell Arteritis / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008297:Male; D018917:Optic Neuropathy, Ischemic / Q000175:diagnosis* / Q000209:etiology; D013699:Temporal Arteries / Q000473:pathology*