In cats, what is the estimated incidence of osteosarcoma among malignant bone tumors?

• A. 10% to 20%
• B. 55% to 85%
• C. 70% to 90%
• D. 90% to 95%

Answer: (B)

The main idea here is how often osteosarcoma shows up as the type of malignant bone tumor in cats. In cats, primary bone tumors are uncommon, but when they occur, osteosarcoma is the most frequent histologic diagnosis. Unlike dogs, where osteosarcoma often constitutes the vast majority of malignant primary bone tumors, cats have a more diverse mix, with other sarcomas like fibrosarcoma and chondrosarcoma also appearing with noticeable frequency. This leads to a typical range reported in the literature of roughly 55% to 85% for osteosarcoma among malignant feline bone tumors. The range reflects real variation between studies, influenced by factors such as sample size, whether tumors arise in the jaw or limbs, and how tumors are classified. So the result is the mid-to-upper range that best represents how common osteosarcoma is as the malignant bone tumor type in cats.