High grade tibiofibular canine osteosarcoma in a 5-year-old female rottweiler

Abstract

Osteosarcoma is a common neoplastic condition of the bone mostly affecting the appendicular bones in dogs. A five-year-old female Rottweiler was presented with a swollen left hind limb. Haematology showed mild nonregenerative anaemia, severe leukocytosis, and moderate neutrophilia with-out left shift, monocytosis, and severe lymphopenia. Fine needle aspirate (FNA) cytology revealed oval to spindle cells with marked cellular pleomorphism, anisocytosis, binucleation, and proteinaceous granules in the background while radiographic examination revealed osteolysis of the tibia and fibular with new bone formation. These findings are consistent with osteosarcoma. A diagnosis of osteosarcoma was made, based on the cytology and radiography. Surgical amputation of the complete left limb was carried out. However, the dog died of leptospirosis one month later. Post mortem examination revealed pulmonary metastasis of the osteosarcoma. Histopathology of the limb growth revealed oval to spindle cells with intracytoplasmic eosinophilic materials and osteoid matrix. Diagnosis and treatment of dogs affected by osteosarcoma should be comprehensive and complete, with adequate follow-up. The marked lymphopenia could be associated with poor prognosis, therefore an index for prognosis in osteosarcoma. The mortality, in this case, could have been related to leptospirosis and associated with the immunosuppression from tumour metastasis.