Primary Amyloidosis
Definition
- Plasma cell neoplasm (rarely lymphoid neoplasm) that secretes abnormal immunoglobulin that deposits in tissues and forms a beta-pleated sheet
Alternate/Historical Names
- Immunoglobulin light chain (AL) amyloidosis
- Myeloma associated amyloidosis
Diagnostic Criteria
- Symptomatic amyloid deposition in organs
- Extracellular amorphous, hyalinized, eosinophilic material
- Often interstitial or in blood vessel walls
- Confirmed as amyloid by Congo Red stain
- Alternate method: electron microscopy
- Deposits should be present prior to development of symptomatic plasma cell burden
- Diagnostic biopsies usually abdominal fat-pad, bone marrow, or rectum
- These are used because of accessibility, rather than predisposition to disease
- Reported sensitivity of abdominal fat pad aspiration highly variable
Dita Gratzinger MD PhD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Initial posting/updates : 9/1/07, 4/16/10
