Pulmonary amyloidosis is a rare manifestation of amyloidosis, ​disease characterized by extracellular deposition of fibrillary protein in the lungs. With lung parenchymal involvement there are two distinct forms:

• nodular parenchymal amyloidosis
• diffuse parenchymal amyloidosis 

The disease can be primary or secondary where the term primary pulmonary amyloidosis is given when the disease is confined to the lungs.​