If a brain tumor gets large will it make a knot on your head?

Typically not: Brain tumors, no matter how huge they get, typically do not cause a knot on your head. Brain tumors can be deadly, yes. Masses (knots) on the outside of your head could be from infection, or bone or soft tissue cancers. Many of these types of cancers are treatable. I strongly encourage you to see a health care provider if you haven't already.

No: Brain tumor can't get thru skull so even largest ones won't produce knot on your head. Instead, large brain tumor will squish soft brain & push it out of way. Displaced brain under pressure causes problems eg headache, seizure, etc. Best to get checked out & monitored closely. Treatment options depend upon type of tumor.

Brain tumors : Are usually inside the skull and do not make "knots" on the outside. The size is less important than the location and the way it looks under the microscope.

No, but: Large benign brain tumors tend to "push" (displace) and "squash" (compress) the brain, while large "bad" (malignant) tumors tend to "eat" (replace) brain. There are instances of intracranial tumors, such as meningiomas, that can involve the skull and cause it to thicken and enlarge. Changes to bone can best be seen on ct (please see http://www.Conciergeradiologist.Com/ct-scan.Html).