Lumpy Tiger Barb

Help I have a 22 gallon tank which has been up and running for 6 months now with very few problems but recently I noticed that the biggest and most dominant tiger barb has developed a lump but I have no idea what it is whether I should seperate her or which medication to use if any.

There are no other signs of disease she is feeding fine and is still charging around the tank like a loon

Any help anyone can give will be appreciated.

Ph 7.5
Amm 0

20% Water changed about every 2 weeks

Tank mates

9 danios (various types)
5 Rosy barbs
4 Green Tigers
3 Tigers

Hopefully a picture will follow if she will stay still for long enough

Best Picture I can get sorry

Bless him, could be bacterial.
http/www.fishpalace.org/danscomments.html#Lump

Thanks for that the link was helpful

I dont have a hospital tank, do you think it would be safe to leave her in with her mates or would that be risking others getting an infection if it bursts.

Well is always best to issolate, but if you can't you will have to medicate the whole tank, good luck.