Head injury?

[Cry86]

My buff brahma who is not quite at laying age just had this mysterious bump appear . No symptoms she's inside now away from the rest.

I do have Guineas whose been randomly attacking certain chickens while free ranging. So its possibly an injury. I mean could be a tumor but I figured its a bit big for a tumor to just appear out of the blue.

Anyone else dealt with something similar?

 

[Wyorp Rock]

I don't believe I've seen anything quite like that.
Any signs of a scab or abrasion under the feathers on the head?

What does it feel like, hard/soft?

I'll tag in @Eggcessive to see if she may have some suggestions.

 

[Eggcessive]

How does the bump feel—hard like a knot, or puffy like fluid or air under the skin?

 

[Cry86]

No scab no abrasions feels like a normal head alittle poof feel if I massage it thats it. Otherwise its like she's a cone head

 

[Cry86]

I got a closer up pic