Help please!

[elaipie]

One of my chickens started limping several weeks ago. When inspecting her I couldnt find any wounds or bumblefoot and thought she may have sprained her ankle. I kept her in a crate so she would rest her foot for several days but it didn;t get better. I let her out again and since the limping didn't get worse just let it go. She seemed fine and healthy otherwise.
Just in the last few days it suddenly got a lot worse. Her tail is pointing down, she is still running around but has a really hard time.
I inspected her foot again and couldnt find anything obvious but squuezed her foot pat a bit and noticed a small hard lump in her foot. it doesn't look anything like bumble and is not infected. More like a piece of cartilage or so..but it moves when I press against it.
I have a hard time believing that this causes her limping.
She did have bumbles in both feet last year..
Does anybody have any idea what might be going on with her?
Thank you!

 

[Eggcessive]

How old is she, and is she still laying eggs regularly? The hard particle in her foot could be scar tissue or just normal. How do her joints look--any swelling in her ankles or hocks? Can you feel of her breastbone for any loss of weight, and her lower belly for any swelling or fullness?

 

[elaipie]

She is only 1,5 years old, she is laying and behaving normally... No swelling or anything else that seems wrong with her legs....I don't think she lost weight and has a normal appetite. Could it be something more internal? Cancer or some other disease that's causing the limping?
Thank you for your help!