I don't think this is fine but I've never met with this particular one and I don't know what it is. I've had some experience with external parasites but never in such a spot. It doesn't look like an embedded parasite to me either but I am no fish vet.
Tumors on fins, on the other hand, I've met with. Usually they will keep growing and will become the size from a cherry to a ping-pong ball. So, first we have to wait and see, as I don't think taking it to a vet and having a biopsy is an option ($$$$$$$). Usually, tumors can be removed by surgery or sometimes they go away on their own. Sometimes they form on fish exposed to heavy metals and other toxins in the water.
From the first pic, your fish is kind of mis-shaped, deformed. This is maybe merely another sign of bad genetics.
