Wondering if bump on top of my head should be of concern

Around  6 months ago I noticed a bump on the crown of my head. It's about the size of a half dollar. I thought nothing of it at first and blamed it on me being unobservant of my own body for 22 years. Recently, it has become sensitive, but not painful to the touch. I have considered this lump sensitivity to be everything from where I wear my pony-tail to a brain tumor. I have terrible allergies and get headaches and migraines fairly often. Since my bad allergies cause things like fatigue, foggy concentration, head/sinus pressure it is hard for me to recognize any other symptoms I may be having due to this mysterious lump. I am pretty concerned about it but am hesitant to bring it up to a doctor in case I am over reacting. Any information you could give on these types of lumps that are sensitive that could potentially cause headaches and fatigue would be greatly appreciated. Thanks.

[cbrn07]

Let you doc look at it my sister gets bumps on her head all the time and they have always been a ganglion cyst (kinda like a hair fol. that has gotten stopped up and encapsulated itself) her family dr usually lances it in the office and removes the capsule .  if that is all it is the only thing you have to worry about is if he cuts it and opens the capsule (it stinks) but again if its moveable ask about the cyst.

[rumpled]

I would bring it up - it could be anything - better safe than sorry!

[LivingInHope]

I once noticed a lump on a man's head whom I worked with.  Years later, he got it checked out & let us know he had a brain tumor removed.  He didn't say what type, but I'm guessing meningioma.  A relative of mine has one between her eyes and I believe it has been a source of headaches for her.  But she got gamma knife and the tumor has shrunk.