<s>[INST] I have a hard lump on the outside of my right knee and pain that shoots through the inside of my knee. What is causing this? I am a 49 year old female and this has been bothering me off&on for about 3 years or more. The pain & irriation seems to get worse after I have been working in the yard, carrying grandchildren, etc., then lay down to rest. [/INST] Hi, dairy have gone through your question. I can understand your concern. If you have history of trauma then it can be hematoma.  Otherwise, it may be some benign cyst or tumor.  You should go for x-ray knee to know the origin of lump.  Then if required go for fine needle aspiration cytology. It will give you exact diagnosis. Then you should take treatment accordingly. Hope I have answered your question, if you have doubt then I will be happy to answer. Thanks for using Chat Doctor. Wish you a very good health. </s>