What Could It Mean If A Mole On My Lower Back Suddenly Feels Like A Painful Pinprick?

Hi there! I am 56 yr old male. I have always had numerous moles on my body. 2 of which were removed as a young child as they Could have turned cancerous. I am currently, in the past few days feeling a pin prick sensation (painful) from a small mole on my lower back. What might that mean if anything. Much thanks!