This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Endometriomas on ultasound appear as 
Select and explain. 
A. Solid with diffuse internal low-level echoes., B. Solid with focal internal low-level echoes., C. Cystic with diffuse internal low-level echoes., D. Cystic with focal hyperechoic internal echoes.
C: Cystic with diffuse internal low-level echoes.
Answer: C: Cystic with diffuse internal low-level echoes. 
Explanation: Endometrioma  classically is cystic with homogenous, low-level internal echoes, i.e ground-glass echogenicity.