<prompt> Which of the tumours are unique to pregnancyLuteomaSerous cystadenomaMucinous cystadenomaTeratoma  <response>: Physiological proliferation of luteal cells in response to gonadotrophins in pregnancy - Theca lutein hyperplasia of pregnancyPathological proliferation of luteal cells in response to gonadotrophins in pregnancy- Luteoma . Luteoma is a type of sex cord stromal tumours Ref: Robbins 8e p1051 