Amyloidosis is a disorder in which amyloid is deposited extracellularly in organs and tissues. It is diagnosed on tissues samples as apple green in Congo red birefringence. Classification of amyloidosis depends on the protein type – AL, AA, ATTR, Ab2M, or polypeptide hormones. AL and AA are the most common.

AL Amyloidosis is composed of fragments of the light chains of immunoglobin molecules. It is produced by B lymphocytes (monoclonal gammopathy-primary), or neoplastic plasma cells (multiple myelomatosis).

AA Amyloidosis is reactive systemic or secondary is due to chronic or inflammatory processes. It is derived from plasma a1-globulins.
Causes are: inflammatory - Rheumatoid Arthritis, Ankylosing Spondylitis, Psoriatic Arthritis, juvenile chronic arthritis, Behcet’s syndrome; chronic infection - TB, leprosy, osteomyelitis, bronchiectasis, infection of decubitus ulcer; chronic inflammation - IBD, familial Mediterranean fever; or neoplasm – Castleman’s disease, Hodgkins, and renal cell.

Most often the pulmonary radiographic findings are normal. When they are present, there can be an interstitial diffuse, micronodular, reticulonodular, or linear pattern. There is often
nodular conglomeration or calcification. There can also be a pleural effusion (most often secondary to heart failure) and adenopathy with calcification.