I have a large bump under the skin on my right knee after a hard fall on my knee on cement.  It has been there for about a year as a direct result of my fall.  It does not hurt unless I kneel on it.  Sometimes it gets smaller when I put hard pressure on it for some time, but then it gets back to its large size again.  What is it?  Can I get rid of it?  I am 70 years old.
Hello, It indicates post-traumatic hematoma after blood collection from the injury, which may remain for a long period of times due to the lapse of initial management in resolving. Ideally, this should be evaluated with an ultrasound of the part and get surgery is done to cure it. Hope I have answered your query. Let me know if I can assist you further.