blue tang with lump

Hi im new to the forum so i have no idea what i am doing but ill give it a go.
We had a white spot epidemic go through the tank and started treatment straight away, which i am still doing as i ceased to early and didnt kill it all, however in the first outbreak our blue tang got a lump on his body which looked like something under his skin as it was the same colour blue as his skin. Now the lump has moved to his top black fin but has stayed blue, so he has a blue lump on his black fin.
I spoke to our LLS but he cant identify it so im asking for help here, he also said its probably a parasite to just remove it with tweezers but im not sure about doing that in case i make it worse.
Also we have clowns, an angel, butterfly, lipstick tang, blenny and a ribbon eel in the tank who are all doing fine with no lumps. And the tang is feeding very well and darting around the tank with no problems but he is rubbing on rocks a bit (which can be normal sometimes) and he doesnt have any white spots.
Thanks in advance for the help.

 

I'm thinking it has to other be parasitic or fungal,do you think it could be what's called calaflour

 

ive tried goggling what you said but cant find it, do you mean the cauliflower disease if so it says that the lumps are white whereas this is definantly blue.. im not sure but getting worried about her

 

Can you please post an image.

 

If it has moved, I would think it's an internal parasite.

 

ok i managed to get a picture but its probably the worst ever, we are going to try and catch her and have a closer look so ill try and get one then, i just dont want to stress her out.
im thinking it might be an internal but which one and could it move to her fins?

 

that is new and weird, good luck

 

ok we managed to get a better picture, it seems to protrude out of the skin.