[boris]

It might have been her sister, Teratoma...

teratoma

SYLLABICATION: ter·a·to·ma

NOUN: Inflected forms: pl. ter·a·to·mas or ter·a·to·ma·ta (-m-t) A tumor consisting of different types of tissue, as of skin, hair, and muscle, caused by the development of independent germ cells.

Teeth are occassionally part of the squamous components of an ovarian teratoma.

[MHGinTN]

Then there is the odd 'fetus in fetu' anomoly.

[AloneAgainNaturally]

Wierd seeing this thread on FR. My mother had this! She always had ehavy periods and I would say at around age 65 had a real bad attack, she thought it was her gallbadder. Turns out she had a fused twin. She had surgery done and it was exactly like your post describes. The "twin" was fused on her ovary and it had hair and teeth. She didn't want to say to much about it and frankly we all didn't want to know that much about it either since it is kind of gruesome.

But there you ahve it, this happened to my own mother about 5 years ago. The other thing I have thought of a LOT since then is that my mother is an exteemly agressive person. Well not in a bad way necessarily, what I mean by that is she is pretty bull headed. Also she is EXTREEMLY intelligent, and I mmean realy smart. Since we found out about the fused twin thing I have often wondered if she has such a strong personality because she has got extra cells in her brain? FWIW, I know form my own mother that this happens.