A 45-year-old man came with a gradually increasing swelling in the popliteal region of his right knee for the past three months. A soft, fluctuant, non-tender swelling was palpable in the popliteal fossa
Ultrasound examination of the right knee shows a cystic lesion in the popliteal fossa with few floating echoes and a small echogenic nodule with acoustic shadowing suggestive of a calcification. A lateral radiograph of the right knee confirmed the finding of a small calcification in the popliteal fossa abutting the tibial plateau.
Baker's cyst
The condition is named after the 19th century British surgeon, Dr. William Morrant Baker who first described it in the late 1800s.