Lump on Bettas side

Question
My blue betta, Mr. Spock, has been developing a lump on his right side, on
the bottom half of his body to the rear. It has been developing for several
months, and is now enormous. I read up about it, and I thought it could be
dropsy, but I keep the water in good condition, and dropsy would appear as a
bloat on both sides, wouldn't it? This is just a lump on one side of the fish. I
also read that he might be constipated and that feeding him peas would help,
but I did that for a week or so and nothing happened. Now Mr. Spock spends
most of his day lying on the gravel and only gets up to eat. I have a feeling
he's going to be gone soon. Do you have any idea what could be wrong with
him?? Thanks in advance. (By the way, I only bought him seven months ago,
so its not old age.)

Answer
I am having computer problems and can not be sure that my reply was sent so please forgive me if my reply sends twice.

Your fish could have a virus that is untreatable (but fish have been known to survive it) or a tumor. I hope it's not a tumor. It could be an internal parasite or an internal bacterial infection. I would try some anti-bactia medicated fish food incase it's an internal infection. If that doesn't work please contact me and I will give you another treatment to try