My son was diagnosis with chiari malformation and a 6mm cyst. Is this dangerous at least the cyst part? He's 9 yrs old, should he have any surgery pleasehelp

Chiari surgery. Based on the age of the child, the presence of a chiari malformation and the cyst i would recommend a consultation with a pediatric neurosurgeon and close follow up as the child reaches the teenage years.
Talk to MD. The answer really depends on the location of the cyst and the symptoms it is producing. Talk to your physician about the options for treatment. The chiari malformation is not a contraindication to anesthesia or surgery should you decide it is needed.
I'm not sure. The cyst- are we speaking of a malformation in the spinal cord like a syrinx or some other type of cyst? If you can find out, i'll be very happy to help you. Many cysts are benign and easy to leave alone. It does matter on location.