Lung

Other nonneoplastic disease

Nodular amyloid (amyloidoma)



Last author update: 1 October 2011
Last staff update: 12 September 2023

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PubMed search: "nodular amyloid" OR "amyloidoma" pulmonary

See Also: Amyloidosis

Elliot Weisenberg, M.D.
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Cite this page: Weisenberg E. Nodular amyloid (amyloidoma). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungnontumoramyloidnodular.html. Accessed February 22nd, 2024.
Definition / general
  • Rare, presents as asymptomatic nodule
  • Usually in asymptomatic elderly with nodule on chest Xray, but no evidence of systemic disease
  • Good prognosis; typically doesn't progress to lymphoproliferative disorders
  • Nodular involvement may be associated with systemic involvement
Case reports
  • 85 year old woman with asymptomatic pulmonary nodules (Case #197)
Gross images

Contributed by Dr. Sajna V.M. Kutty, MVR Cancer Centre and Research Institute, Kozhikode, Kerala, India

Rib tumor

Microscopic (histologic) description
  • Well circumscribed amyloid, often with lymphocytes (T cells) and plasma cells
  • Granulomatous reaction to amyloid common, often calcification and ossification
Microscopic (histologic) images

Contributed by Dr. Sajna V.M. Kutty, MVR Cancer Centre and Research Institute, Kozhikode, Kerala, India

Amyloid deposits

Apple green birefringence



Case #197

Lung nodules - H&E

Congo red - polarizing microscopy

Cytology images

Case #197

Fine needle aspiration of lung nodule

Positive stains
  • Congo red staining: glassy, salmon pink amorphous material with apple green birefringence under polarized microscopy
  • Clonal restriction of plasma cells (kappa or lambda staining, not both)
Electron microscopy description
  • Amyloid fibrils
Differential diagnosis
  • Primary pulmonary lymphomas with amyloid production: < 1% of pulmonary lymphomas have amyloid deposits, usually age 70+ years with marginal zone or SLL / CLL subtypes, often with lymphatic tracking and reactive lymphoid follicles; the presence of evenly distributed lymphocytes in the nodule and invasion of the pleura is specific for lymphoma
  • Hyalinizing granuloma: history of exposure to Histoplasma or TB, collagen is Congo red negative
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