Histogenetically they are classified as sex cord-stromal tumours.

They are typically estrogen-producing and they occur in older women (mean age 59; 84% after menopause).

[1]) 60% of patients present with abnormal uterine bleeding, and 20% have endometrial carcinoma.

Grossly and microscopically, it consists of the ovarian cortex.

Microscopically, the tumour cells have abundant lipid-filled cytoplasm.