Hemangiosarcoma

A malignant tumor of endothelium forming irregular vascular clefts and channels.

Gross Appearance:
•Ill-defined areas of intradermal hemorrhage which bleed extensively
•May be multicentric
•Extremely infiltrative
•Large areas of hemorrhage and necrosis

Histology:
•Neoplastic endothelial cells are large and bulge into the vascular spaces
•Proliferation of spindle cells

•Interwoven pattern resembling fibrosarcoma and leiomyosarcoma

Breeds At Increased Risk
Breed	Odds Ratio	95% Confidence Limit	Probability
Italian Greyhound	8.729	3.202 - 23.794	0.001
Whippet	7.333	2.998 - 17.936	0.001
Irish Wolfhound	5.114	2.269 - 11.528	0.002
American Pit Bull Terrier	3.763	2.209 - 6.410	0.001
Greyhound	3.654	1.884 - 7.086	0.001
Pointer	3.650	1.504 - 8.860	0.014
Saint Bernard	2.817	1.163 - 6.825	0.036
Golden Retriever	2.377	1.977 - 2.859	0.001
Beagle	1.715	1.197 - 2.457	0.006
German Shepherd	1.582	1.219 - 2.054	0.001
Mixed Breed	1.305	1.132 - 1.505	0.001

Breeds At Decreased Risk
Breed	Odds Ratio	95% Confidence Limit	Probability
Miniature Poodle	0.437	0.247 - 0.774	0.002
Husky	0.431	0.193 - 0.963	0.029
Cockerspaniel	0.395	0.241 - 0.647	0.001
Rottweiler	0.387	0.184 - 0.815	0.006
Lhasa Apso	0.370	0.138 - 0.989	0.042
Dachshund	0.326	0.122 - 0.872	0.013
Doberman Pinscher	0.271	0.135 - 0.543	0.001
Yorkshire Terrier	0.183	0.046 - 0.732	0.003
Shih Tzu	0.153	0.038 - 0.614	0.001

Sex Distribution (N=898)

Sex

Status

Percent

Male	(45.0%)
51.2%

intact

(28.1%)

32.6

neutered

(16.9%)

18.6

Female	(55.0%)
48.8%

intact

(23.9%)

18.8

neutered

(31.1%)

30.0

(normal sex distribution)

Anatomic Location (N=859)
Site	Percent
Hindlimb	20.5
Abdomen	18.4
Thorax	15.9
Forelimb	14.4
Neck	8.3
Head	7.8
Back	4.2
Multiple	3.8
Perineum	3.0
Scrotum	2.2
Tail	1.5