Lung
Other nonneoplastic disease
Nodular amyloid (amyloidoma)
Author: Elliot Weisenberg, M.D.
Last author update: 1 October 2011
Last staff update: 21 August 2020
Copyright: 2003-2023, PathologyOutlines.com, Inc.
PubMed search: "nodular amyloid" OR "amyloidoma" pulmonary
See Also: Amyloidosis
Table of Contents
Definition / general | Case reports | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology images | Positive stains | Electron microscopy description | Differential diagnosisCite this page: Weisenberg E. Nodular amyloid (amyloidoma). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/lungnontumoramyloidnodular.html. Accessed May 29th, 2023.
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 of the Week #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 of the Week #197
Lung nodules - H&E
Congo red - polarizing microscopy
Cytology images
Case of the Week #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
