Synchronous Appendicular Osteosarcoma and Chronic Lymphocytic Leukemia in a Golden Retriever

다국어 초록 (Multilingual Abstract)

An 11-year-old neutered male Golden Retriever presented with lameness of the left forelimb, anorexia, and lethargy. Computed tomography revealed a left humeral mass displaying an aggressive bony lesion with sclerotic changes, raising suspicion of a malignant bone tumor. A hemogram showed marked mature lymphocytosis and moderate nonregenerative anemia. Additional diagnostic methods, including bone marrow aspiration and flow cytometry, definitively diagnosed T-cell chronic lymphocytic leukemia (CLL). Left forelimb amputation was performed, and osteosarcoma was diagnosed based on histopathological examination. Chemotherapy with chlorambucil and prednisolone was initiated for the CLL. Three weeks after treatment, the patient’s clinical signs of anorexia and lethargy resolved, with improvement in lymphocytosis and resolution of anemia. To the best of our knowledge, synchronous osteosarcoma and chronic lymphocytic leukemia have not been reported in veterinary medicine. The concurrent occurrence of osteosarcoma and leukemia has seldom been reported in human medicine, and genetic predisposition is proposed to be a potential risk factor. This is the first documented case report of concurrent osteosarcoma and chronic lymphocytic leukemia detailing its clinical features and diagnostic processes.