How does a benign process typically affect the integrity of tissue planes?

• A. It crosses between planes
• B. Does not cross between planes
• C. It causes skin thickening
• D. It creates acoustic shadowing

Answer: (B)

Benign processes typically respect tissue planes, growing by expansion and pushing against adjacent tissues rather than invading across them. This means the planes stay intact on ultrasound, and the lesion often appears well-circumscribed with a smooth boundary. When a process is limited within its own plane, it preserves the separation between layers, which is a reassuring sign. In contrast, malignant or more aggressive processes tend to cross or disrupt these planes as they infiltrate surrounding tissue, leading to plane distortion or irregular spread. Features like skin thickening or posterior acoustic shadowing are not direct indicators of plane integrity and can occur with other conditions, so they don’t explain the typical behavior of benign lesions regarding tissue planes.