That is exactly what happened to me! I had Chiari decompression surgeryin June, developed a csf leak in the hospital, but it stopped. For six months fluid still showed up on my MRI but no problems. Then I developed a small bump, but thought nothing of it,. I woke up 6 weeks ago with a bump at the back of my neck the size of an orange and immediaty went back to my neurosurgeon who told me I hd a csf leak that required surgery. After surgery the Dr said there had been a broken suture, it was repaired, I spent 5 days in bed in the hospital with a lumbar drain, and went home after 6 days. Receovery was much easier, and am back to work after three weeks. I feel much better than I did even after my initial surgery. Starnge all this happened 7 months after surgery, but as Dr said there must have been a pre existing condition that casued this.