Best Answer - Chosen by Voters
Wow, I've seen about a dozen or so teratomas in my time and most usually include hair, bones, even eyes, and sometimes organ tissue like liver, kidney, or other "stuff". They're easy to treat, and often the treatment includes steroidal meds that can cause hair thinning. In fact, most of the treatments include agents that can thin hair. Also, because the teratoma is located on the ovary, like an ovarian cyst, your system could be giving off hormones that thin hair.
Yes, most of the current material does indicate the potential for hair loss or thinning but the good news is the teratoma can be removed and hopefully without removing the ovary, and with a laparoscope so the scar will be minimal.
Further good news, your internist could consider testosterone therapy for hair growth but fair warning, you could get a very hairy snooge and butt. It can also cause facial hair so be conservative at first.