What characteristic appearance does a cystic mass have on ultrasound?

• A. Homogeneous with defined borders
• B. Hypoechoic with irregular shapes
• C. Anechoic with well-defined edges
• D. Echogenic with a solid core

Answer: (C)

A cystic mass is typically characterized by its appearance on ultrasound, which is anechoic with well-defined edges. Anechoic means that the mass does not produce echoes on the ultrasound image, resulting in a dark or black appearance. This occurs because the fluid within the cyst transmits the sound waves with little to no reflection. Well-defined edges indicate that the borders of the cyst are clear and distinguishable from the surrounding tissue, a trait that is often associated with benign cystic structures.

In contrast, other appearances such as homogeneous with defined borders suggest a solid mass rather than a fluid-filled cyst, while hypoechoic with irregular shapes would indicate a more complex or potentially malignant mass. Echogenic with a solid core refers to solid masses that reflect sound well and do not contain the characteristic fluid that identifies cysts. The clarity and anechoic nature of cystic masses play a crucial role in their identification and management in clinical practice.