I was diagnosed very quickly last summer, immediately really.
But, a long time ago I felt pressure in my ears and asked to be referred to an ENT. The guy was an arrogant jerk. Gave me a once-over of a hearing test, scoffed at me and told me nothing was wrong.
When I have a spare minute, in all seriousness, I am going to write him a letter now telling him of my diagnosis and what an a** he was, if I can track him down. (Have changed health plans and don't remember his name.)
I doubt my problem was diagnosable then, as my hearing was fine, no other symptoms (I do have some fullness on both sides from allergies) and the tumor must've been teensy -- so I don't even consider it a misdiagnosis -- but there is no excuse for treating a patient that way. (I was in my 20s, very healthy, not a malingerer or alarmist -- it was the first time he'd met me!)
About five years ago, I had an episode of falling-down vertigo. It resolved quickly with no other symptoms and was assumed to be viral. Was that the tumor? Probably, but not necessarily -- they'd had five cases of vertigo virus that weekend at my physicians' group, so maybe that's what I had, too!
Last summer when I started complaining, I had a whole concert of symptoms all at once -- imbalance, dizziness, ear fullness, almost undetectable facial weakness. The ENT immediately ordered an audiogram -- very mild high-frequency loss -- and MRI -- and there it was. Though I will likely be treated by other surgeons in the end, I am grateful to him for his quick action.