Post History

Plausibility of "multi-type transmissible animal cell tumor" to form more complex structures. 

There's apparently a type of transmissible cancer that came from [new world dogs](https://en.wikipedia.org/wiki/Native_American_dogs) thousands of years ago, [the Canine transmissible venereal tumor](https://en.wikipedia.org/wiki/Canine_transmissible_venereal_tumor).  As I understand, this self replicating surviving cancer has DNA from new world dogs no longer found in the current canine population.  It's its own "thing", not from a virus, radiation, or chemical phenomena.  

I would like to postulate the possibility of more than just one type of cell metastasizing in a animal.  Would it be possible for multiple types of "cancer" cells (or at least host foreign animal cells) to work in unison to create new structures? For example, extending a cardio vascular system, or nervous system through out the tumor, or, at the most far fetched side of things, a new appendage, like a cancerous "ear" formation (like a bunch of ears starting to grow in an area on the dog/animal due to this foreign cell "infection"?). 

Even if this couldn't happen in general, would this be feasible with compatible immune systems, such as those found with inbred animals?