It might sacroiliac inflammation. I had a similar problem, and was diagnose with that. I got steroid injections in the joint between the sacrum and ilium, and have had much less trouble. Having the pain after sitting is a sign of this problem.
Have you mentioned your fear of a spinal tumor to any of the doctors?
Other than pain, you don't mention any of the other symptoms - https://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments/Spinal-Tumors
Have you had an x-ray done? Any other imaging?
Since your symptoms aren't constant, I'd say it's not likely to be a tumor, but definitely share your fears with your doctor. Also, work on your posture, and see if that helps.
My symptom has lasted for half a year and It doesn’t happen everyday. Maybe every other week or so.
It can happen from any position.. but mostly sitting
Thank you for answering.
I’ve been to my doctor, neurologist and a rheumatologist.. none of them have said anything about spinal tumors. They don’t seem that worried. My physical neurological exam showed nothing (they tested my reflexes, numbness etc) Is it possible to pass a neurological exam perfectly if you have a spinal cord tumor?
Would a spinal cord tumor even show symptoms like the one I have? Or is it more constant? I have no numbness or anything else but a mild lower back ache. I do have poor posture though.
It could be a pinched nerve, an inflamed disk, or a host of other things.
How often does it happen? Have you noticed it when getting up from a certain position, like sitting crossed-legs, or does it happen in any position? How long has it been going on?
If you're afraid of a spinal cord tumor, which of course is possible, but the chances of it being something else are much, much higher, then you should get it checked out. Not going to the doctor doesn't change the diagnosis.