These are tumours derived from the mesenchymal stroma of the gonad and account for 5 - 10% of all ovarian neoplasms.
Many are endocrinologically functional, able to synthesise gonadal or adrenal steroid hormones. The ovarian stroma is sexually bipotential, so the hormones secreted may be male or female.
There are four main cell types:
- granulosa cells
- theca cell
- sertoli and Leydig cell
Granulosa-theca tumours are typically oestrogenic; Sertoli- Leydig, androgenic; and lipid cell tumours, virilising.
The characteristics of each tumour is described in the linked item.