They could be anything from encapsulated parasitic worms, cysts, to abscesses. I would have an experienced herp vet sample one of them and culture it to see if it's an infection, a cyst, abscess, etc. Your cham was most likely a wildcaught adult given the little "battle scars" from his life in the wild.
Whatever you do, don't let the vet just automatically start him on Baytril (antibiotic that can be hard on chams unless you monitor them carefully and hydrate them very well). Ask for a culture and sensitivity test or at least a biopsy to check for a parasite.