Sick Midas.. thoughts?

It seems I've got a little black cloud following me as far as fish lately. I'm posting this for a friend. She has a 12 year old, full grown female Midas cichlid that has suddenly developed some interesting problems. The fish is housed in a 140gallon with a canister filter, heater, all the usual stuff. Not a whole lot of decorations, rocks and some plastic plants, but the fish is a terrible digger.

About a week ago she developed a slight enlargement of the tissue at her shoulder, just beneath the start of the dorsal. It was slightly red, but the scales were smooth, she was eating and her usual behavior had not changed appreciably. As the days went by she developed five small pin-point red marks on her skin just at the scale overlaps and the swelling enlarged. It is now quite large, about 1/4" raised from the rest of her body and covers an area about 1" by 3" down the fish. The scales are still smooth. She's lethargic, still eating okay but not as hungry as usual. The gills also seem to be slightly darker red, but this is hard to be sure. Nothing has been changed to this tank in probably a year. A 30% water change is done by a professional maintenance guy every week, no changes in water quality in ages.

Sorry I cant provide any photos, I'll try to work on that in the next few days. Do we have any ideas? I can only think up one disease that causes swelling in tissues and that's Cryptobiosis.. caused by a protozoan infection. Anything else, besides a tumor?

Thanks for the help
>Sarah

Thanks for the suggestions.. I wonder what was the other board? Maybe its one I already frequent and just didnt see the thread. If you could post the website I'd be really grateful!

The midas is the only fish in the tank actually since she's a little uneven tempered.. The last time she had a 'tankmate' was a year and a half ago, which is the last time she was given feeders.. they were extra Least Killifish that I had breed in my tanks and couldnt find room for. I know those were clean since I raised them. Her diet is usually cichlid pellets, both animal and veggie types, and perhaps once a month or so she'll get a treat of Cichlid Chow (frozen spirulina, daphnia, brine shrimp and a little beefheart is what's in those I believe).

I did raise the temperature and I'm considering suggesting that my friend treat with Kanamycin sulfate (Kanacyn on the market.. which is very hard to get now actually). I'm pulling filter material from the canister and setting it up in a highflow tank to try to keep the bacteria alive.. I imagine I'll feed them with Ammonia.

I'd like to go the salt route but it would take a whole lot of salt at this point I think, and she seems to get worse each day. I know its a little silly but this fish is so old that its like a child for my friend. Hopefully we'll pull this out.

Thanks for the help!
>Sarah

Thanks so much for the help.. I'm pretty sure I found the right thread under DaisyDarko handle. The picture she had of the lump of her fish is remarkably similar to the lump I'm seeing.. location is just different. I'm sad to see that the person from the other board lost her fish though..

For now I've increased oxygen content with an air pump and started a course of Kanamycin sulfate at 150 mg/ml. It has 'seemed' to help the fish out, she has started eating again and is behaving a good deal better..not nearly as lethargic. It looks like, from the other board, that if the lump turns purple its a sign that the end is near.

If I had to guess I'd call this an internal bacterial infection that is causing a cyst, probably filled with lymphocytes.

Thanks again for the help! I really appreciate it!

>Sarah