Liposarcoma in the lung of a poodle dog

A 15-year-old intact female poodle dog was referred to a local animal clinic showing signs of dyspnea. A radiographic examination revealed multiple nodules in the lung. The following day, the animal died and a necropsy examination revealed multiple nodular masses of varying sizes in the lung. Microscopically, the tumor cells were composed of round to polygonal cells resembling adipocytes with little or no collagenous stroma. Most of the cells contained clear cytoplasmic vacuoles with the nucleus at the periphery while the other cells contained varying numbers of smaller vacuoles. The immunohisto-chemical evaluation yielded a positive reaction to S-100 and vimentin. Negative results were obtained for pancytokeratin, smooth muscle actin, desmin, epithelial membrane antigen and CD68. This case was diagnosed as a well-differentiated liposarcoma.