What term describes a sonographic appearance with fluid and solid areas within the same mass?

The term that describes a sonographic appearance with both fluid and solid areas within the same mass is "complex." In the context of sonography, when a mass exhibits both cystic (fluid-filled) and solid components, it is referred to as complex. This appearance is significant because it can influence the diagnostic considerations and potential management of the mass.

In contrast, the other terms describe different echogenicity characteristics. Isoechoic refers to a mass that has similar echogenicity to the surrounding tissue, making it difficult to distinguish. Hypoechoic indicates that a structure reflects fewer ultrasound waves compared to surrounding tissues, appearing darker on the sonogram. Hyperechoic, on the other hand, describes a structure that reflects more ultrasound waves, appearing brighter. These terms do not convey the combination of solid and fluid that is central to the concept of a complex mass.