Is this black spot worrisome?

[Hsb0234]

My last barred rock was severely disabled and passed away in January. This has me freaked out because I’ve bonded with this girl, and I don’t want to lose another one. I never noticed this black spot and recently it’s been getting bigger I think? It’s basically all black, idk what else to say about it but I’m scared. Is it cancer? Just a birth mark? I never noticed it before so maybe it’s growing? I’m really worried. She eats, drinks, everything seems normal, just this spot.

 

[Eggcessive]

How long has it been there? It might be a bruise or old blood under the scale, but I would keep an eye on it. Chickens can get melanoma, but it is very rare, and it would thicken and have multiples.