Zit (Spot) on Mole

Hi Doc.

I have 5 moles on the right side of my face and the biggest one had a small white ***** spot on it. I quickly got rid of it as it looked horrible but why would this happen? I've never had a spot on any of my moles before.

Though becuase of this, the mole expanded, it grew outwards, now it hurts.

I contacted ' Sk;n ' who do mole removals in the UK and they said they can remove it if i give the word.

Just wondering why a spot came about on the mole and is it normal?