Extensive amyloid deposits in bone marrow aspirate smears

Amyloid light-chain (AL) amyloidosis is the most common form of systemic amyloidosis. It can cause progressive organ dysfunction and eventually death, mainly due to cardiac involvement. Amyloidosis may rarely present as extensive amorphous, purplish-blue deposits in marrow aspirate smears. Demonstration of congophilic property and apple-green birefringence under polarized light in aspirate smears can allow a rapid diagnosis of amyloidosis.