Lymphoma and plasma cell neoplasms
Plasma cell neoplasms
Primary amyloidosis

Author: Nikhil Sangle, M.D. (see Authors page)

Revised: 3 April 2017, last major update March 2011

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PubMed Search: primary amyloidosis lymphoma

Cite this page: Primary amyloidosis. PathologyOutlines.com website. http://pathologyoutlines.com/topic/lymphomaprimaryamyloid.html. Accessed December 13th, 2017.
Definition / general
  • Monoclonal proliferation of plasma cells secreting free light chains (usually lambda), which are deposited as amyloid
  • Amyloid: fibrillary protein, 95% composed of nonbranching fibrils 7.5 to 10 nm thick with variable length in a β-pleated sheet conformation; 5% is serum amyloid P component, made of proteoglycans and highly sulfated glycosaminoglycans
  • Amyloid is deposited in various tissues causing local damage
Terminology
  • Due to primary amyloidosis (AL type), secondary amyloidosis (AA type) or familial amyloidosis (AF type)
Clinical features
  • Only primary amyloidosis is associated with plasma cell dyscrasias
  • Causes include overt multiple myeloma (20%), plasmacytomas of bone marrow or minor population of plasma cells
  • Rare (2,000 cases / year in U.S.), usually ages 60 - 70 years, 2/3 are men
  • Symptoms: weight loss, fatigue, heart failure, peripheral neuropathy, nephrotic syndrome (1/3), bleeding (acquired factor X deficiency due to its binding to amyloid protein)
  • 90% have serum or urine monoclonal protein, although electrophoretic spike may be small; detect with serum / urine immunofixation or serum free light chain ratio analysis if amyloidosis suspected
  • Biopsy is 80% sensitive in rectum and abdominal wall fat, 50% in bone marrow (may be confined to blood vessel walls only)
  • Median survival 1 - 2 years; death due to amyloid related cardiac disease, renal failure, infection, hemorrhage
  • Patients with plasma cell myeloma and amyloidosis have shorter survival than amyloidosis alone
Case reports
Treatment
  • Alkylating agent chemotherapy
Microscopic (histologic) description
  • Pale pink amorphous material, "apple green" birefringence with Congo red stain and polarized light microscopy
  • Check vessel walls in bone marrow biopsies for amyloid deposition
Electron microscopy description
  • Fine, linear, nonbranching fibrils