Lymph nodes - not lymphoma
Inflammatory disorders (non-infectious)
Amyloid

Authors: Jaya Balakrishna M.D. (see Authors page)

Revised: 3 November 2016, last major update November 2016

Copyright: (c) 2003-2016, PathologyOutlines.com, Inc.

PubMed search: amyloid lymph node
Cite this page: Amyloid. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphnodesamyloidosis.html. Accessed December 5th, 2016.
Definition / General
  • An uncommon disease caused by the deposition of abnormal proteins within the soft tissues
Essential Features
  • Extracellular deposition of amorphous, eosinophilic, hyaline substance
  • Amyloid is Congo red positive
Terminology
  • Amyloid, amyloidosis, amyloid lymphadenopathy
Epidemiology
  • Rare
Sites
  • Cervical, supraclavicular and mediastinal lymph nodes
  • Any lymph node group can be affected
Pathophysiology
  • Results from abnormal folding of proteins
  • Proteins that form amyloid can be (a) normal proteins that have an inherent tendency to fold improperly, associate and form fibrils and do so when they are produced in increased amounts and (b) mutant proteins that are prone to misfolding and subsequent aggregation
Etiology
  • As part of primary systemic amyloidosis
  • As part of reactive systemic amyloidosis
  • In uremic patients
  • In non Hodgkin lymphoma
  • As isolated primary deposits in lymph nodes
Clinical Features
  • Lymph node enlargement
  • In secondary cases, depending on the primary condition
Diagnosis
  • Histologic demonstration of amyloid
Laboratory
  • If associated with monoclonal proteins of B cell lymphoma, serum and urine protein electrophoresis will demonstrate monoclonal proteins
Radiology Description
  • None specific
  • Enlarged lymph nodes
Prognostic Factors
  • Generalized amyloidosis tends to have poor prognosis
Case Reports
Treatment
  • Treatment of the associated condition
  • Treatments inhibiting protein misfolding and fibrillogenesis are under study
Gross Description
  • Enlarged lymph node with firm waxy cut surfaces
Gross Images

Images hosted on PathOut server:

Contributed by Dr. Mark R. Wick

Micro Description
  • Hyaline-like amorphous eosinophilic depositions positive for Congo red staining
  • Polarizing microscope shows unique yellowish green birefringence
Micro Images

Images hosted on PathOut server:

Amyloidosis of lymph node

Contributed by Dr. Mark R. Wick



Images hosted on other servers:

H&E

Various images

Acellular, amorphous, eosinophilic amyloid deposits

Polarized light

Cytology Description
  • Hyaline-like amorphous material on cytology smears
  • Acellular and associated with connective tissue
  • Eosinophilic to blue / green with Pap stain, deep blue with Diff-Quik
Positive Stains
Negative Stains
Electron Microscopy Description
  • Clusters of round / oval nodules, often enclosed with cytoplasmic processes of macrophages or reticulum cells
  • Fibrils are nonbranching, 7.5 nm in diameter, form parallel bundles close to cytoplasmic membranes
Differential Diagnosis