Interstitial amyloidosis in sporadic inclusion body myositis

Introduction/Aims Intracellular congophilic inclusions within muscle fibers, although nonspecific, are one of the pathological hallmarks of sporadic inclusion body myositis (sIBM). Extracellular amyloid deposits in muscle, on the other hand, are the canonical findings of amyloid myopathies, which occur with or without systemic amyloidosis. Methods We reviewed the muscle biopsy database (1998–2020) to identify sIBM patients with extracellular...