Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the most common mass found in the popliteal fossa?

1. Hemangioma

2. Ganglion cyst

3. Baker's cyst

4. Abscess

The correct answer is: Baker's cyst

The most common mass found in the popliteal fossa is a Baker's cyst, which is also known as a popliteal cyst. This fluid-filled sac is typically associated with knee joint conditions such as arthritis or meniscal tears. The cyst forms when synovial fluid accumulates in the popliteal fossa, causing swelling. Baker's cysts can present as a palpable mass behind the knee, especially in individuals experiencing knee pain or inflammation. While other options such as ganglion cysts and abscesses can also occur in the knee area, they are less common specifically in the popliteal fossa compared to Baker's cysts. Hemangiomas, although they can occur in various locations, are not typically found in this area. Understanding the commonality of Baker's cysts in clinical practice is important, especially when evaluating patients with knee problems, as they can sometimes mimic other pathologies or provide insight into underlying joint conditions.