HEMANGIOSARCOMA

•prevalence of dermal HSA in cats is highly variable ranging from none to most common site of HSA

•HSA often occurs in unpigmented skin or white cats due to exposure to ultraviolet light

•sex predisposition: male

•median age 12.5 years

•site predilection: dermis and subcutis of head (especially pinna) or inguinal subcutis

•tumor cells are immunoreactive to factor-VIII related antigen and vimentin

•treatment: wide surgical excision as traditionally unresponsive to chemotherapy and relatively radioresistant

•prognosis is guarded with local tumor recurrence rate of up to 50% following histologically complete resection and metastatic rate of up to 25% at the time of diagnosis

HEMANGIOMA

•sex predisposition: male

•median age 10 years

•pigmented skin with no site predilection although other papers report a predilection for white-haired areas

•tumor cells immunoreactive for factor-VIII related antigen and vimentin

•no local tumor recurrence following complete resection