"My infant with Cysts in lymphatic system"

My 9 month old son suddenly (literally with in hours) had a lump size of a golf ball appear on his neck. Managed to rush to GP who said "keep an eye on it" so I went back next morning to see different GP. She sent us to my local hospital. They did x ray and ultra sound and saw more in his chest. We were then sent to Edinburgh Sick Kids for MRI. This showed how deep these were and that they had pushed his wind pipe over that much it looked like a C. The cysts were pressing on blood and oxygen vessels. Sick Kids Edinburgh referred us to Queen Elizabeth University Hospital Glasgow.

We arrived and had an operation three days later. My 9 month had to learn to hold his head up and crawl etc all over again after his 9/10 hour surgery. We were advised that the chances of it reoccurring were "very slim to nil". As a result of the surgery my son also had some nerve damage - especially to his eye which is now droopy and does not dilate. Just over 3 months later I noticed swelling again. I arranged to see the consultant a few weeks later. By now the swelling was a lump much like the previous and growing!  Their reaction was "that's disappointing" and is referring us for a mri.

This will be sent out in due course- which he advised may not be this side of the new year. I left in utter shock and unable to process the reality as I was expecting mri and more urgency. I phoned the next day to speak to him again as I feared I may not have caught all the information as we were in and out in minutes to be told that I would not get an appointment without having the MRI first (another 8-10 weeks away). I am really at a loss on what to do now due to previous experience- do I wait those 8 weeks and hope it's not grown internally as much as before (as it could have killed him the first time? I do not know the course of action to pursue. I have photos from the first and current lump - both as big as each other. The problem the last time was the growth internally. This current lump seems to be growing faster.

Update: The consultant apt for Feb has been pushed to the end of March! More delay