Corpus luteum cyst occurs due to:
Grandiose lutein cyst

Functional, non neoplastic.enlargement of the ovary.:,
Persistent corpus luteum cyst may cause local pain,
tenderness or delayed menstruation
Cysts are often palpable clinically
Usually resolve spontaneously

​Theca lutein cyst

They are associated tropphoblastic disease, chorionic gonadotrophin therapy (HCG) & clomiphene therapy.
They are bilateral and filled with straw coloured fluid.
They resolve spontaneously after elimination of the H mole, therapeutic curettage, destruction of chorio-carcinoma or discontinuation of gonadotrophin therapy.
HCG
HPL
Estrogen
Progesterone