Professional and Linguistic Assessments Board (PLAB) Practice Exam

What appearance is indicative of a chocolate cyst in ultrasound imaging?

1. Ground glass appearance, unilocular

2. Multiple solid masses

3. Homogeneous echogenicity

4. Complex fluid collection

The correct answer is: Ground glass appearance, unilocular

The characteristic appearance of a chocolate cyst on ultrasound imaging is described as having a ground glass appearance, typically presenting as unilocular. This type of cyst is often associated with endometriosis and contains thick, old blood, which gives it a distinctive echogenicity that resembles ground glass. In ultrasound imaging, the ground glass appearance is due to the high protein content and the density of the hemosiderin pigment within the cyst. This phenomenon results in the cyst appearing as a homogeneous, less reflective area that does not present as simply fluid-filled but rather has some internal echogenicity, which is different from other fluid collections that might appear anechoic or only with thin walls. In contrast, other options do not accurately describe the typical features of a chocolate cyst. Multiple solid masses would suggest a different pathology, while homogeneous echogenicity might imply a simple fluid-filled cyst without the unique content that defines a chocolate cyst. A complex fluid collection typically indicates the presence of septations or debris, which also does not align with the classic presentation of a chocolate cyst on ultrasound.