Basically the subject says it all. I saw this scene as a kid and it terrified me. A nurse walks into a patients room to find this blob-alien type creature with arms and all I can remember is that the blob rips/tears off her leg.
What was this from? Does it ring any bells?
This might be a dumb answer, but could this be the Blob remake from the 90's?
You mean the 80s
uh, no. I'm pretty sure it was something else. The creature was like a ball with arms. (A basketball-sized ball)
Basket Case, maybe?
Was this the nurse?
(http://www.bmoviegraveyard.com/Misc/wotw.jpg)
hey, maybe that's it! What movie is that picture from?
It's from the old 80's War of the Worlds tv series. The episode is called "Unto us a child is born."
There are some dark blobby aliens in that series, but in that particular episode it was a human/alien hybrid that tore off the nurse's leg (with very human-looking hands).
Aside from that, the scenario is very much like you described. She walks into the room and the mutant baby thing reaches out from under the bed and rips her leg off and kills her before getting loose in the hospital.