Clinicopathologic and proteomic characteristics of intratubular cytoplasmic AL amyloidosis

Light-chain (AL) amyloidosis is a severe complication of plasma-cell disorders or B-cell lymphoma, secondary to monoclonal Ig light chain (LC) deposition in tissues and organs. Kidney involvement is found in two-thirds of patients at diagnosis.1 AL amyloidosis frequently affects glomeruli and vessels, and the interstitium in roughly half of the cases.2 Originally, the term “amyloidosis” was used exclusively to describe extracellular deposits that generate birefringence under polarized light after Congo red staining.