How do tumors grow things like eyes, teeth, brain tissue and organs when the human body often can’t grow those by itself?

Question

There was a post about a woman who grew a “homonculus tumor”, with brain tissue, teeth, a spinal nerves and other organs. But how? Human bodies can’t grow those things after birth, AFAIK. For example, once your adult teeth are in, that’s it. So how are tumors able to do this? Are the cells in tumors different from those found normally in human body?

In: 1354

Answer 1

The “homonculus tumor” you mention was a fake, by the way… so that explains how that worked. Others in the comments have explained the real thing