Synovial Cyst is very similar to a Ganglion one often sees on
the the back of one's wrist. It is a benign (non-cancerous)
problem. As can be seen in the above illustration, a synovial
facet cyst compresses the nerve root from above in stead of
from below (like the herniated disk also seen on the other side).
Unlike the bulging disk, Synovial Facet Cysts do not generally
resolve, and usually require surgery.