Bacillary Angiomatosis

 Also associated with organ transplantation, systemic steroids, and leukemia

Clinical Issues

• Occurs in both adults and children

• Can involve any cutaneous site; uncommonly involves mucosal sites, deep soft tissues

• Typically presents with multiple lesions, often pyogenic granuloma-like


• Reddish brown, dermal-based nodular, hemorrhagic lesion


• Nodular to dome-shaped/polypoid, dermal-based vascular proliferation

• May have overlying epidermal ulceration and collarette (similar to pyogenic granuloma)

• Vessels are arranged in loose lobular configuration

• Endothelial cells show mild enlargement and oval to epithelioid shape

• No significant cytologic atypia or atypical mitotic activity

• Background stroma shows fibrosis, edema, and mixed inflammatory infiltrate with many neutrophils

• Infiltrate is composed of numerous neutrophils with nuclear dust, macrophages, lymphocytes, and focal collections of basophilic granular material (bacterial collections)

Top Differential Diagnoses

• Pyogenic granuloma
image Ulceration and peripheral epidermal collarette are typically present but lack organisms of BA

• Kaposi sarcoma
image Dermal tumor composed of slit-like vessels lined by atypical spindle cells

Bacillary Angiomatosis
Low-power examination of bacillary angiomatosis (BA) demonstrates a superficial dermal proliferation of blood vessels in a lobular configuration image associated with edema and inflammation.

High Magnification of Bacillary Angiomatosis
High magnification of BA demonstrates a proliferation of small blood vessels with swollen endothelial cells image surrounded by edema and inflammation image.

Warthin-Starry Stain in Bacillary Angiomatosis
Warthin-Starry silver stain preparation shows numerous clusters of bacterial organisms image around blood vessels.

Warthin-Starry Stain at High Magnification
Warthin-Starry stain demonstrates positive staining of numerous clusters image and single bacterial organisms.



• Bacillary angiomatosis (BA)


• Epithelioid angiomatosis


• Reactive vascular proliferation associated with Bartonella species bacterial infection


Infectious Agents

• Caused by infection with Bartonella (gram-negative coccobacilli) species, usually Bartonella henselae or Bartonella quintana
image Most patients have history of cat exposure (and may have preceding scratch or bite)

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Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Bacillary Angiomatosis

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