My 8 year old son developed a lump to the side of his left knee 2 days ago.  The pediatrician thinks it is either a ganglion cyst or bakers cyst.  However I am taking him to an orthopedic surgeon to verify this with further testing.  I want to make sure 100% that this is what it is, and not some type of tumor.  It is some what moveable, but from what Ive read so are some type of soft cell sarcomas.   Any information you can provide would be helpful.  The lump goes Up and down, it is more long than wide, not a perfect circle, by any means.  More oblong.  Thank you.
Welcome to Chat Doctor. 1. Your description suggest me that it's a ganglion cyst, which is developed from a joint structures like tendon, ligament and nerve sheet.2.It's good to get it examined what you are doing, to evaluate the lesion / lump - an ultrasound examination will help.3. Ultrasound will help in evaluating the nature of the lump, its source and extensions.4. But ideal investigation of choice is MRI for one joined - which will give accurate diagnosis from which structure it comes from.5. Treatment is followup, if any discomfort a small incision and Chat Doctor.  Good luck. Hope I have answered your query.Anything to ask do not hesitate. Thank you.