Conversation: The conversation between human and AI assistant.
[|Human|] I have a swollen area behind my knee. I can hardly walk because the pain is so bad in and behind my knee. The pain goes down my leg. The area hurts but also feels a little numb. I may have been stung by a wasp in that area several weeks ago. Would an infection from a wasp sting cause this problem
[|AI|]  Hello, I have studied your case and most probably you are having backer cyst enlargement. This is collection of fluid in the posterior part of the knee due to either a meniscus tear or a knee arthritis.  You should get MRI of the knee to see the cause than accordingly we can plan for further management. If there is meniscus cyst than you can remove it arthrscopically. If there is Backer cyst then you need to get it removed from posterior aspect of the knee joint.  I hope this answer will be useful for you. Let me know if there is any other followup questions. Thanks