Systemic AL amyloidosis with high bone marrow plasma cells (BMPCs) infiltration: a case report and literature review

Light chain (AL) amyloidosis is a complex and often fatal disease caused by misfolded protein deposition characterized by monoclonal immunoglobulin light-chain fibrils in tissues and organs (1). This light chain protein, usually produced by a small and indolent plasma cell clone, is responsible for positive staining with Congo red when observed under polarized light, a gold standard for the diagnosis of AL amyloidosis (2).