Skin nonmelanocytic tumor
Vascular tumors
Bacillary angiomatosis


Topic Completed: 1 January 2017

Minor changes: 6 November 2020

Copyright: 2001-2021, PathologyOutlines.com, Inc.

PubMed search: bacillary angiomatosis [title] skin

Joel Tjarks, M.D.
Sara C. Shalin, M.D., Ph.D.
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Cite this page: Tjarks J, Shalin S. Bacillary angiomatosis. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticbacillaryangiomatosis.html. Accessed April 18th, 2021.
Definition / general
  • Reactive vascular proliferation due to infection by Bartonella henselae or Bartonella quintana
  • Most commonly affects immunocompromised individuals (especially those with HIV)
Essential features
  • Lobular proliferation of capillaries with ectatic vessels lined by prominent endothelial cells
  • Neutrophils, lymphocytes and histiocytes are frequently present
  • Purplish grey bacterial colonies may be seen
Epidemiology
  • May affect adults and children
  • Most commonly affects immunocompromised individuals
Sites
  • Can occur in any cutaneous site
  • Rarely occurs in mucosa or internal organs
Etiology
  • B. Henselae is acquired via cat scratch or bite in 2/3 of cases
Clinical features
  • Red, smooth papules and nodules which are widely distributed
  • May mimic Kaposi sarcoma and pyogenic granuloma clinically
Laboratory
  • PCR and IHC may be helpful in identifying organisms
Case reports
Treatment
  • Antibiotics - typically doxycycline
Clinical images

Images hosted on other servers:

Papules on face, chest, abdomen and back; mass lesion on face

Exophytic lesion on neck

Small, cherry angiomata-like lesions and nodules

Microscopic (histologic) description
  • Lobular proliferation of capillaries with ectatic vessels lined by prominent endothelial cells in edematous stroma
  • Neutrophils, lymphocytes and histiocytes are frequently present
  • Purplish grey bacterial colonies may be seen, especially near neutrophils
  • Peripheral collarette may be seen (low power histologic image mimics pyogenic granuloma)
  • Warthin-Starry special stain will highlight Bartonella organisms
Microscopic (histologic) images

Contributed by Tammie Ferringer, M.D.

Bacillary angiomatosis profile



Contributed by Nathan Lee, M.D.

Bacillary angiomatosis



Contributed by Mark R. Wick, M.D.

Breast skin

Steiner stain, breast

Positive stains
Differential diagnosis
  • Kaposi sarcoma: spindled vascular proliferation with slit-like vascular spaces, plasma cells, HHV8 positive, lacks purplish grey bacterial colonies
  • Pyogenic granuloma: lobular proliferation of capillaries, but typically somewhat less inflamed (unless ulcerated) and no purplish grey bacterial colonies
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