Which features define a simple cyst on breast ultrasound?

Which features define a simple cyst on breast ultrasound?

• A. Anechoic Interior With Posterior Acoustic Enhancement
• B. Internal Echoes With Dirty Posterior Shadowing
• C. Irregular Thick Walls With Septations
• D. Mixed Solid and Cystic Components

Answer: (A)

A simple breast cyst is fluid-filled, so its interior appears completely anechoic, with no internal echoes. Fluid also transmits sound well, producing posterior acoustic enhancement—brightening behind the cyst. These two features together are the hallmark of a simple cyst. The walls are typically thin and smooth, and there are no septations or solid components. If you see internal echoes, debris, posterior shadowing, irregular or thick walls with septations, or any solid-cystic mixture, the lesion is no longer simple and warrants closer evaluation.

A simple breast cyst is fluid-filled, so its interior appears completely anechoic, with no internal echoes. Fluid also transmits sound well, producing posterior acoustic enhancement—brightening behind the cyst. These two features together are the hallmark of a simple cyst. The walls are typically thin and smooth, and there are no septations or solid components. If you see internal echoes, debris, posterior shadowing, irregular or thick walls with septations, or any solid-cystic mixture, the lesion is no longer simple and warrants closer evaluation.