BETTA TUMOR?! Help please!

Hi! I’ve had my betta for about 3 months now and she’s just beautiful. However, when I first got her she had a blue scale right behind her gill which I never thought anything of. I’ve noticed it change over time but today I’ve really noticed just how large it’s actually become. It’s now all white and there’s no blue tint anymore. If I look at her straight on it does bulge out of her side. I’m not sure what it is or if I should be worried about it. I’m thinking it could be a tumor?! I just don’t know and I need help. I attached pictures so you could see what I’m talking about! Please help!!

Hi and welcome to the forum

She's a lovely looking fish and the pictures are great. They show a white growth that could be a tumour or fungal infection. Is there any chance you can use a needle to carefully touch the white bit and see if it's hard or soft? You will have to catch the fish out to do this.
If the white patch is fungus it should be soft and a bit of it might come off when you touch it.
If the patch is firm or hard it is a tumour.

There is no real cure for tumours in fish but if it's fungus then it can be treated with Methylene Blue.

Is there any chance you can use a needle to carefully touch the white bit

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This is by far the most idiotic advice you have given to date dude. I can't even.................

I am now going to carefully read every post you make and call you out on every bad bit of advice.

well how else do you expect to identify it as a fungal infection or a tumour?

it doesn't have to be a needle but it needs to be something fine enough so you can touch the white bit without stabbing the rest of the fish. And most people have a sewing needle in their house so I suggest that. Use a toothpick if you want I don't care. But we need to know if it is soft and squishy or hard.

You can treat the tank with Methylene Blue and that will cure the fungus but it will wipe out the filter bacteria.

You can ignore it and not treat it and if it's a fungus it will kill the fish.

What ideas do you suggest Nick?
How would you proceed to identify this as a tumour or fungus?