Lymph nodes & spleen, nonlymphoid
Lymph nodes-infectious / parasitic disorders

Topic Completed: 1 June 2013

Minor changes: 3 April 2020

Revised: 1 February 2019, last major update June 2013

Copyright: 2003-2020,, Inc.

PubMed Search: Actinomyces [title] lymph nodes

Page views in 2019: 943
Page views in 2020 to date: 485
Cite this page: DePond W. Actinomyces. website. Accessed August 3rd, 2020.
Definition / general
  • Rare
  • Associated with poor dental hygiene (is a normal inhabitant of the oral cavity)
  • Causes lymphadenopathy
Gram stain
  • Gram positive, filamentous branching bacteria
  • Appropriate dental care and antibiotics
Case reports
Gross description
  • Tan-white cut surface, multiple pinpoint white spots
Microscopic (histologic) description
  • Marked capsular fibrotic thickening with thick fibrous bands dividing nodes into nodules
  • Also follicular hyperplasia, marked interfollicular fibrosis and multiple interfollicular microabscesses containing focal Actinomyces colonies with classic sulfur granules (may require deeper levels to identify)
  • No palisading of histiocytes around the abscesses
  • Numerous macrophages are present in germinal centers
Microscopic (histologic) images

Images hosted on other servers:
Missing Image

Various images

Missing Image

Cervical cytology

Differential diagnosis
Additional references
Back to top