I have knee pain and the MRI shows a popliteal cyst, distal femor lesion. My doctor did a biospy and said it was inconclusive whether cancer is present, so he sent me to an orthopedic oncologist at a well known cancer hospital.
The oncologist told me he is 99% sure that it is not cancer, but a cyst.
He told me that the cyst made a hole in the bone and he wants to operate to
remove the cyst and fill in the hole with animal marrow or another substance that will fill in the bone and harden.

I did research on-line and found that the popliteal cyst can make a hole in the joint lining, but it seems that several people with this condition chose
steroid shots and draining instead of surgery. I also read that if the underlying cause of the cyst is not addressed (like arthritis or torn miniscus),
that the cyst may return even if surgery is performed.

The oncologist told me that if I do not have surgery the bone can break, or the bone marrow could become loose and enter my bloodstream. I did not read anything like this in my research so I am confused and scared about my choice of treatment.

If anyone can shed some light on this condition I would deeply appreciate it.

Thanks!