A soft, round, fluid-filled mass near a joint that is usually painless and may cause swelling or discomfort is most consistent with which lesion?

• A. Ganglion Cyst
• B. Synovial Sarcoma
• C. Lipoma
• D. Abscess

Answer: (A)

Soft, fluid-filled periarticular masses that are usually painless fit best with a ganglion cyst. These cysts arise from the joint capsule or tendon sheath and contain viscous, mucinous fluid similar to synovial fluid. They present as well-defined, mobile lumps near a joint and may transiently swell or cause mild discomfort, especially if they compress nearby structures. They often transilluminate and tend to fluctuate in size with joint activity.

Abscess would typically be painful, warm, red, and may have fever or signs of infection. Lipoma is usually a soft, mobile, subcutaneous fatty mass and not fluid-filled or specifically tied to a joint. Synovial sarcoma is a malignant tumor that usually presents as a deeper, often enlarging mass near a joint, may be painful, and lacks the classic cystic, fluid-filled character.