What does short vs long zone of transition between normal and abnormal bone indicate?

• A. Short zone indicates benign disease; long zone indicates more aggressive process
• B. Short zone indicates aggressive process
• C. Zone length is not informative
• D. Long zone indicates benign disease

Answer: (A)

The length of the zone of transition between normal and abnormal bone is a radiologic clue to lesion aggressiveness. A short, narrow zone with a sharp, well-defined border typically signals a benign process that expands by pushing surrounding bone and allows reactive bone to form. A longer, wide zone with ill-defined margins suggests an infiltrative, more aggressive lesion that replaces normal bone.

So, the statement that a short zone indicates benign disease and a long zone indicates a more aggressive process is the best interpretation. The other options imply that zone length is not informative or that the opposite associations apply, which doesn't fit how bone lesions interact with surrounding bone.