My niece has a lump that has started one week ago?

My niece has a lump that has started one week ago. Saw ENT specalist and suggested she get a mri under sedation, she is 5 yrs old. Any ideas what it could be? the colour looks nasty. There is a 2 week wait before she can get a mri. Should we be concerned if it gets bigger / spreads in 2 weeks?

Age: 5
Female
Medications: