<s>[INST] My daughter has had 4 lymph nodes removed for cervical cancer that had spread to her lymph nodes..she apperars to have developed a fluid pouch that is the size of a lemon..for 2-3 weeks she has extreme pain  in the back of her leg that does not ease up..24/7 pain..could this be  a seroma? [/INST] Hi, Thanks for writing in. It is possible that there is thrombosis of the veins in her legs. This is an emergency condition, and she must get evaluated for it. The legs have deep veins and when there is any pressure effect of the cancer on the veins in the pelvis, it can cause the blood flow in leg veins to become slow. When this happens then the blood stops flowing and gets clotted in the leg veins. She can get a Doppler scan of lower limbs done for the venous system to know if there is deep venous thrombosis. The problem is that this clot can get dislodged at any time and reach the heart and then cause cut off of blood supply to lungs leading to death. If detected and confirmed then it can be treated by medicines to dissolve the clot and make the venous flow normal. Please do not worry. </s>