Soft lump around anus

Question
Hi Heather,

I have a Syrian hamster for 2 months now and 3 days ago, I noticed a lump around its anus (near the tail).  

The lump measures about 0.7cm in diameter, and it is soft to touch.  When I touch it, it does not seem to cause the hamster discomfort.  The lump is pink in colour and has no fur.  It does not seem to be dirty etc.  The strange thing is, the lump can retract back so sometimes, my hamster's bottom looks as usual.  I am not sure what the sex of my hamster is - I *think* it is male, but I cannot be sure.

What is this lump?  I am a bit worried because I thought it might be piles (if hamsters get piles).  He has plenty of water and food for his cage, and seem to be in good health.

Thank you very much for your help.  I tried to put in as much info as possible.

Phoebe

Answer
What you may think is a lump sounds like a male hamster's testicles. They appear as soft lumps, or as one large lump with perhaps a small crease in the middle. It also looks like the hamster has a pronounced buttocks. You say they can retract, and this is exactly what testicles can do in a male. They grow and shrink in size throughout the day. Your hammy sounds like a perfectly healthy male to me.