LIPOSSARCOMA BEM DIFEERENCIADO MESTASTÁTICO EM OSSO DE CÃO – RELATO DE CASO

Abstract

The authors describe the case report of a 9-year-old male Akita dog treated for intermittent lameness for several days. A simple radiograph of the limb revealed a significant, aggressive bone lesion in the right femoral shaft, with adjacent swelling. During radiographic positioning, the limb fracture occurred, and the patient underwent amputation surgery, with the presumptive morphological diagnosis of bone liposarcoma. A chest radiograph and abdominal ultrasound were used to investigate metastasis, both negative. Immunohistochemical studies for histogenic identification of the tumor, which stained positively for vimentin, S-100, and Ckit, confirmed the diagnosis of well-differentiated liposarcoma of bone. Although the patient recovered well after surgery, 25 days later he developed dyspnea and a nonproductive cough, as well as difficulty standing upright. Imaging tests were repeated, revealing nodules in the lung parenchyma and a neoplasm in the right perirenal region, consistent with foci of metastatic spread. An ultrasound-guided biopsy of the abdominal tumor revealed an undifferentiated mesenchymal neoplasm of fatty origin, consistent with metastasis. Due to the patient's deteriorating health, the owner opted for euthanasia. Although some authors have stated that liposarcoma has a low propensity to metastasize, in this study it was shown to be extremely aggressive. The well-differentiated histological type appears to have more aggressive behavior compared to the other subtypes, although the histological classification of liposarcomas is not yet well defined in the veterinary literature.