Red cap oranda goldfish

Question
My goldfish has a growth on it's forehead.The growth is the same color of his skin, but in the middle underneath it, it is black. The black is round and has two lines, it is spider looking. The fish is fine eat and swims aroud.I'm really worried because it has gotten bigger.I think it is a male for I had gotten two at a time and this one is so much bigger.He is 6''long with tail and about 2 1/2" wide.The smaller one is fine, the only thing about her is that about 80% of the time she swims upside down but has always done that. I't funny but I guess i't ok. I hope you can help me with the goldfish with the growth. Sharon

Answer
Oranda goldfish have natural growths on their heads. This is called a wen. I would be more worried about why your other goldfish is swimming upside down. That is not normal, and is a very real sign that there is an issue. Most likely a swim bladder problem, cut back on the feeding and make sure you are doing enough water changes.