This is a hip replacement with a large diameter metal head made from chrome cobalt alloy. There is a large fluid collection and thickened necrotic tissue. This is referred to as a pseudotumour. It is not a malignant growth, and it is not cancer. I revised it to a titanium shell with X linked polyethylene liner, and titanium stem with a ceramic head.
![](https://i.ytimg.com/vi/4rxFT018i8M/maxresdefault.jpg)