Amyloidosis

A disease associated with deposition of amyloid in tissues. There are multiple different types of amyloids but the one typically seen in hematologic disorders is the AL (Amyloid Light chain) type which usually is associated with an underlying plasma cell neoplasm. The AL amyloid is associated with plasma cell neoplasms and are usually monoclonal light chains (kappa or lambda) leading to linear nonbranching fibril aggregates measuring 7.5-10 nm in width and ultimately comprised of beta-pleated sheets which can be highlighted with the congo red stain in tissue.