Baker’s cyst

A fluid-filled lump behind the knee. A Baker’s cyst is caused by increased pressure in the knee joint due to a buildup of fluid in a disorder such as rheumatoid arthritis. Most Baker’s cysts are painless, and some disappear spontaneously. Occasionally, a cyst may rupture, producing pain and swelling in the calf that can mimic a deep vein thrombosis (see thrombosis, deep vein). Diagnosis of a Baker’s cyst is confirmed by ultrasound scanning. Treatment is rarely needed.

 

Online Medical Dictionary: Your essential reference to over 5000 medical terms.