What were the sensitivity and specificity of cytology for diagnosing a bone sarcoma?

• A. 97% sensitivity and 100% specificity
• B. 83% sensitivity and 82% specificity
• C. 50% sensitivity and 60% specificity
• D. 70% sensitivity and 90% specificity

Answer: (A)

Cytology for bone sarcoma is evaluated by how well it identifies disease (sensitivity) and how well it rules out disease in non-diseased cases (specificity). In this context, the reported performance is extremely high: sensitivity around 97% means that nearly all true bone sarcoma cases are detected by cytology, and specificity at 100% means there are no false positives among non-sarcoma lesions. So a positive cytology result showing malignant bone tumor features (such as malignant osteoblasts with osteoid production) is essentially definitive for sarcoma. A negative cytology still leaves a small chance of disease, so if clinical suspicion remains, histopathology or further workup is warranted. The other options reflect lower sensitivity and/or specificity, making them less consistent with the demonstrated diagnostic accuracy.