Some Sort Of Fungus?

I'm not sure if you can tell by these pics, but at the base of the tail, not on the fin but where the body meets the tail fin, there are white swollen patches on both sides. I just noticed these yesterday and today they look the same. None of my books say anything about it and I've been told it could be a number of different things such as a parasite or a fungus. Because there's no sign of a wound I don't think it's an injury, but I can't be sure. Maybe someone can recognize it.

Can't tell in the pics much.
Do the pacthes look white and fluffy in appearance.

I know, out of the 10 pics I took, that's all I could get. He's obviously active he won't stop moving.

No, the patches don't appear fluffy, just swollen and ruffed up.

What colour are the patches as in one pic they look abit pinky.
Any excess mucas on the body or gills or the fish.
Any sign of flicking and rubbing.
Does the patch look sore in appearance.
Does the patch resemble a caulifower.

How many gallons or litres is the tank.
How many fish and which type.
Water stats in ammonia, nitrite, nitrate, and ph.