I have a large golf ball size lump on my back it use to be filled with Thick white pus and was squeezed then stopped being able to squeeze it. It  turned big golf ball size it now has red bumps in a circle and recently besides having red it is very tender like a pimple
Hi, Thanks for writing to Chat Doctor. It might be a sebaceous or Desmond cyst, which following the rupture, got infected and turned into an abscess now. You need to show it to a surgeon for its excision under cover of antibiotics now. Regards