Lump on foot arch

I have a pea sized lump in the middle of my plantar fascia on my left foot. It is sore when pressed but doesn't really bother me when running unless I land on a protruding rock/tree root. I am currently putting the miles in training for the L50. My question is will I be doing and long term damage or is this likely to suddenly go one day? It hasn't improved or got any worse over the last 2-3 months.
Cheers

I know someone that has that, it sounds like it could be ledderhose syndrome or Plantar fibromatosis. So far it's not been a problem but I'd consult a specialist if it does.