What is this lump on my rooster's back?

[Eggcessive]

Could you get some newer pictures? Does it look like there are feathers under the area? There are some skin cancers and other tumors that can be common. You could try to probe the area or lance it, if there seems to be any pus. If it doesn’t look like an abscess, I’m not sure that I would cut into it. Let us know if it gets larger or smaller.

 

[The Dim Side]

Could you get some newer pictures? Does it look like there are feathers under the area? There are some skin cancers and other tumors that can be common. You could try to probe the area or lance it, if there seems to be any pus. If it doesn’t look like an abscess, I’m not sure that I would cut into it. Let us know if it gets larger or smaller.

It's hard to compare it from the angle I was getting yesterday. I can't tell if it's bigger. But I think that discoloration is getting worse. But I also may have just not seen it all yesterday? I'm not sure! >.<

 

[Eggcessive]

Can you try to open the scab and see if you can get any yellow solid pus out, or if it only bleeds like tissue? It is looking more like a tumor to me by the crater like appearance, but an ingrown feather cyst may be possible. Here is a collection of tumors and cysts on chickens, with some possible diagnoses of a vet:
https://bitchinchickens.com/2023/12/04/avian-pathology-cases-42/