[Vierville]

Most growths are benign and some are just lumps of fatty tissue, but if it grows rapidly then I would say it IS an emergency and should be removed if Athena is young enough and in good enough health to cope with surgery.

Sometimes surgery is not a good idea as the impact of surgery on the hamster is worse than leaving the growth.

Also, I saw you mentioned that the growth doesn't have a 'stalk', but most growths are not external, they are under the skin or deeper, sometimes in the organs even.

A hamster can live with a growth or even multiple growths for many months without it being an issue.

Sadly, growths are extremely common in hamsters and I've had three hamsters so far who have had them.