Hard Lump

3 year old English staffy appeared with this hard under the skin lump around 2 weeks ago. We were supposed to have it checked yesterday, but the little guy was too needle phobic to be sedated (yes, even with oral meds given at home first)

We will try again on Monday, and I know it could be anything and hard to know without a biopsy but was wondering if anyone would have an idea if I should be concerned.

Pictures of how it looks no flash vs flash

Thanks x