October 2016

I- N19



Signalment (JPC #1961061):  Unspecified breed and age, dog

HISTORY:  A small dermal mass

HISTOPATHOLOGIC DESCRIPTION:  Haired skin and subcutis:  Expanding the dermis and subcutis, elevating the mildly hyperplastic epidermis and compressing adnexa is a 5 X 10 mm, well-circumscribed, un-encapsulated moderately cellular neoplasm composed of spindle cells that form multiple blood-filled vascular spaces that are separated by variably thick bands of a fibrous connective tissue (collagen) matrix.  Neoplastic cells have indistinct cell borders, small amounts of eosinophilic fibrillar cytoplasm, oval to elongate nuclei with finely stippled chromatin and variably distinct nucleoli.  Anisokaryosis and anisocytosis are mild and there is less than 1 mitotic figure per 10 HPFs.  Multifocally vascular spaces are partially occluded by fibrin emboli along with small aggregates of dark granular pigment (hemosiderin). Multifocally there are low numbers of lymphocytes and plasma cells are scattered throughout the stroma as well as in the dermis surrounding adnexal structures. At the dermal-epidermal junction there are also multifocal melanin containing macrophages in the dermis (pigmentary incontinence). Apocrine glands and hair follicles are mildly ectatic and there is increased clear space with ectatic lymph vessels within the superficial dermis (edema).   

MORPHOLOGIC DIAGNOSIS:  Haired skin and subcutis: Hemangioma, breed unspecified, canine.


Signalment (JPC #1945545):  Unspecified breed and age, cat

HISTORY:  A dermal mass on the paw

HISTOPATHOLOGIC DESCRIPTION:  Haired skin and subcutis:  Effacing the deep dermis and subcutis and extending to deep and lateral borders is an un-encapsulated, infiltrative, densely cellular neoplasm composed of spindle cells which form variably sized blood-filled vascular spaces and often bulge into the lumen, occasionally wrap collagen bundles, and in more densely cellular areas are arranged in short, haphazard streams and bundles, all separated by a variable amounts of collagenous matrix.  Neoplastic cells have indistinct borders, small to moderate amounts of eosinophilic fibrillar cytoplasm, irregularly round to oval nuclei with finely stippled chromatin, and one to two variably distinct nucleoli.  There is moderate anisocytosis, anisokaryosis, and scattered single-cell necrosis, and the mitotic count is up to 5 per 10 HPFs.  Multifocally throughout the neoplasm, there are variably sized areas of hemorrhage and necrosis, and low numbers of scattered lymphocytes, plasma cells, neutrophils and hemosiderin-laden macrophages. Within the superficial dermis there are scattered lymphocytes, plasma cells, and macrophages containing melanin (pigmentary incontinence) as well as ectatic lymph vessels (edema). 

MORPHOLOGIC DIAGNOSIS:  Haired skin and subcutis:  Hemangiosarcoma, breed unspecified, feline.



Hemangiosarcoma (HSA)





Hemangioma:  Trauma induced bleeding may occur

Hemangiosarcoma (especially visceral)










Lymphangioma, lymphangiosarcoma:  Tumors of lymphatic endothelium; rare in all species

Feline ventral abdominal angiosarcoma

Scrotal hamartoma:  Rare, proliferative vascular lesion seen in older dogs with pigmented scrotal skin; not a true neoplasm; vascular hamartomas can occur anywhere in the skin (though the scrotum is the more common location)

Angiomatosus: Secondary to lymphedema; there is marked hypoplasia of the deep lymphatic vessels with an increase in extracellular matrix and inflammation; prominent vascular proliferation (neovascularization) in clusters; on EM proliferating vascular structures have a continuous basement membrane



Hemangiosarcomas:  Reported less commonly in the cow (may be associated with bracken fern), horse, pig, goat, chicken and sheep

Single case reports:


  1. Anwar S, Yanai T, Sakai H. Immunohistochemical detection of urokinase plasminogen activator and urokinase plasminogen activator receptor in canine vascular endothelial tumours. J Comp Pathol. 2015;153:278-282.
  2. Anwar S, Yanai T, Sakai H. Overexpression of peroxiredoxin 6 protects neoplastic cells against apoptosis in canine haemangiosarcoma. J Comp Pathol. 2016;155:29-39.
  3. Arenas-Gamboa AM, Mansell J. Epithelioid haemangiosarcoma in the ocular tissue of horses. J Comp Pathol. 2011;144:328-333.
  4. Cole PA. Association of canine splenic hemangiosarcomas and hematomas with nodular lymphoid hyperplasia or siderotic nodules. J Vet Diag Invest. 2012;24(7);759-762.
  5. Goldschmidt MH, Hendrick MJ. Tumors of the skin and soft tissues. In: Meuten DJ, ed. Tumors in Domestic Animals. 4th ed.  Ames, IA: Iowa State Press; 2002: 99-101.
  6. Gross TL, Ihrke PJ, Walder EJ, Affolter VK. Skin Diseases of the Dog & Cat. 2nd ed. Ames, IA: Blackwell; 2005:148-15, 399-401, 741-753.
  7. Gruntzig K, Graf R, Boo G, et al. Swiss canine cancer registry 1955-2008: Occurrence of the most common tumour diagnoses and influence of age, breed, body size, sex and neutering status on tumour development. J Comp Pathol. 2016;155:156-170.
  8. Jennings RN, Miller MA, Ramos-Vara JA. Comparison of CD34, CD31, and factor VIII-related antigen immunohistochemical expression in feline vascular neoplasms and CD34 expression in feline nonvascular neoplasms. Vet Pathol. 2012;49(3);532-537.
  9. Kakiuchi-Kiyota S, Arnold LL, Yokohira M, Koza-Taylor P, Suzuki S, Varney M, Pennington KL, Cohen SM. Evaluation of direct and indirect effects of the PPARγ agonist troglitazone on mouse endothelial cell proliferation. Toxicol Pathol. 2011;39(7):1032-45
  10. Kakiuchi-Kiyota S, Crabbs A, Arnold LA, Pennington KL, Cook JC, Malarkey DE, Cohen SM. Evaluation of expression profiles of hematopoetic stem cell, endothelial cell, and myeloid cell antigens in spontaneous and chemically induce hemangiosarcomas and hemangiomas in mice. Toxicol Pathol. 2013;41;709-721.
  11. Lindemann DM, Carpenter JW, Nietfeld JC, Gonzalez E, Hallman M, Hause BM. Multicentric T-cell lymphoma and cutaneous hemangiosarcoma in a captive cheetah (Acinonyx jubatus). J Zoo Wildl Med. 2015;46(4):961-966.
  12. Mauldin GA, Kennedy JP. Integumentary system. In: Maxie MG ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 1. 6th ed., Philadelphia, PA: Elsevier Saunders; 2016: 726-727.
  13. Muller G, Scott D, Miller W, Griffin C. Veterinary Dermatology. 6th ed. Philadelphia, PA: W.B. Saunders; 2001:1297-1301.
  14. Nambiar PR, Turnquist SE, Morton D. Spontaneous tumor incidence in rasH2 mice: review of internal data and published literature. Toxicol Pathol. 2012;40(4):614-23.
  15. Perez-Ecija A, Estepa JC, Barranco I, Rodriguez-Gomez IM, Mendoza FJ, Gomez-Laguna J. Verrucous hemangioma with pseudoepitheliomatous epidermal hyperplasia in an adult horse. Vet Pathol. 2014;51(5):992-995.
  16. Shoemaker M, Barrie M, Holman H, et al. Pathology in practice. J Am Vet Med Assoc. 2015; 248(2):153-155.

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