Skin - Nonmelanocytic tumors
Vascular tumors
Bacillary angiomatosis

Author: Joel Tjarks, M.D. (see Authors page)
Editor: Sara C. Shalin, M.D., Ph.D.

Revised: 18 January 2017, last major update January 2017

Copyright: (c) 2001-2017, PathologyOutlines.com, Inc.

PubMed search: bacillary angiomatosis [title] skin

Cite this page: Bacillary angiomatosis. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/skintumornonmelanocyticbacillaryangiomatosis.html. Accessed January 21st, 2017.
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

Micro 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
Micro Images

Images hosted on PathOut server:

Contributed by Dr. Tammie Ferringer:

Bacillary angiomatosis profile



Contributed by Dr. Nathan Lee:

Bacillary angiomatosis



Contributed by Dr. Mark R. Wick:

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