ABSTRACT
A 10-year-old, castrated male, English cocker spaniel dog was presented for evaluation of a mass in the left forelimb. Physical examination revealed a solitary subcutaneous mass measuring 2.7 x 2.1 x 1 cm in size. Radiographs and ultrasonography showed a well-circumscribed, focally mineralized, non-invasive to muscle layer mass without signs of further bone invasion and periosteal reaction. Cytologic evaluation of the mass through fine needle aspiration revealed a mesenchymal cell type malignant tumor without distant metastasis. An excisional biopsy was performed for definitive diagnosis and the mass was diagnosed as cutaneous hemangiopericytoma. This case report presents disagreement between fine needle aspiration and histopathology during diagnostic procedures of cutaneous hemangiopericytoma in a dog.