Symptoms may include swelling behind the knee, stiffness, and pain. If the cyst breaks open, pain may increase, and there may be swelling of the calf. Rupture of a<unk>  may also cause bruising below the medial malleolus of the ankle (Crescent sign).
Baker's cyst
Ganglion
Bartholin's cyst
Aneurysm
Tarlov cyst
Deep vein thrombosis
Askin's tumor
Neoplasm