What are the characteristics of a simple ovarian cyst on ultrasound?

A simple ovarian cyst typically displays specific ultrasound characteristics that aid in its identification. It is predominantly anechoic, meaning that it appears dark on the ultrasound image due to the lack of internal echoes, which indicates that it is filled with fluid. The walls of a simple cyst are thin, allowing for a clear distinction between the cyst and the surrounding ovarian tissue. Additionally, a simple cyst will present with smoothly defined margins, further confirming its benign nature and distinguishing it from more complex cystic or solid lesions that may have irregular borders.

These attributes help in the differential diagnosis of ovarian cysts, as simple cysts are often benign and may be observed over time without intervention, while cysts exhibiting thickness, irregular margins, or internal echoes could indicate a more complex pathology, potentially requiring further evaluation or management.