Random thought whilst brushing my teeth

[onedrunkcat]

I was brushing my teeth this morning when a strange random thought pooped into my mind:  Why is that when some cells clump together and grow in a woman's uterus it is called, by some, life or a human being, but when other cells clump together and grow in say, the lungs or the breasts or some other organ, it's called cancer?

(I'm not trying to make a comment on anything, I was simply under-caffeinated when this popped into my head and I thought it was interesting.  Can one person's pregnancy be another person's cancer?  Probably).