CASE REPORT: LIPOSARCOMA WITH MICROVASCULAR PROLIFERATION IN A COCKATIEL (Nymphicus hollandicus)

A five-year-old female cockatiel weighing 117 g was presented with a fast-growing mass beside the uropygial gland. Excisional biopsy was performed and the mass measured [Formula: see text][Formula: see text]cm in size and weighed 30.6 g. On the surface of cut sections, the mass was yellow-brown with white or yellow colloidal substances and red exudate. Histopathology showed that the tumor mass was covered by the skin and located in the deep dermis and hypodermis. The tumor consisted of abundant vascular adipose tissue and lipoblasts with intracytoplasmic lipid droplets, which varied in size. Also, small, well-differentiated blood vessels, with varied degrees of congestion and dilation, were observed within the tumor. Histochemically, staining with Oil red O produced a positive reaction in which the lipid droplets presented a reddish color. Immunohistochemistry produced positive staining for Desmin and successfully marked the muscular layers of blood vessels. On the basis of these results, a rare case of liposarcoma with microvascular proliferation adjacent to the uropygial gland was diagnosed in a cockatiel.