Actually, there is a type of tumor, called a cholesteotoma, that grows within the middle ear cavity. The tumor is slow growing, and is benign. But the problem is, they have been know to break through the attic of the middle ear. The attic is actually very thin bone, from that point the brain and its fluid is now exposed, and fluid can then drain in to the middle ear cavity etc.
http://www.drhull.com/EncyMaster/C/cholesteotoma.html
But in your case I doubt you have anything to worry about. You would have a hearing loss if you did have a cholesteotoma, and secondly these thigs to not go unoticed.
Thank you for your comment. It has reassured me that I dont have a brain problem. I did see the doc and I have to take some ear drops, I have to go back again, so then I will mention to her about it smelling like vinager.
Cerebrospinal fluid ("brain liquid") does NOT drain into the middle or outer ear.
It DOES normally go into the INNER ear (the compartment where your hearing and balance organs are located), but the inner ear is surrounded by the hardest bone in the body. Fluid doesn't get from the inner ear into the ear canal. Thus, the drainage you are experiencing is NOT coming from your brain.
Brain cancer has nothing to do with ear infections, and vice versa.
But ear infections should be seen by, or discussed with, a doctor.
As for drainage smelling like vinegar, I don't know; please see your doctor. And good luck.
Nancy T.