This is a group of rare tumours that recapitulate the supportive cells of the gonads. They are divided into four categories:
- Granulosa-stromal tumours (25-30% of cases)
- Sertoli-stromal tumours
- Mixed tumours
- Steroid tumours
Overall, sex cord-stromal tumours make up 8% of all ovarian neoplasms. As a group, they can occur over a wide age range.
The most common type, with fibroma (4%), granulosa cell (2%) and thecoma (0.5%) making up the majority of cases. They typically occur in post-menopausal women and cause post-menopausal bleeding due to hormone production. Granulosa cell tumours contain granulosa cells (small round blue cells, cleaved nuclei) in a stroma of theca and spindle cells; thecomas contain theca cells (vacuolated cytoplasm) and spindle cells; fibromas contain spindle cells only.
Sertoli-stromal tumours are either Sertoli-Leydig tumours which contain tubules lined by Sertoli cells with a stroma that contains Leydig and spindle cells, or Sertoli cell tumours which lack the Leydig cells. Poorly differentiated Sertoli-Leydig cells contain spindle cells only.
This is an uncommon group; an important member is gynandroblastoma which contains both granulosa cell and sertoli cell components of at least 10%. It usually occurs in young adults.
Steroid tumours include stromal luteoma and Leydig cell tumours. They often occur in post-menopausal women. Macroscopically these tumours are yellow. Microscopically the tumour is made up of cells with eosinophilic cytoplasm; Leydig cell tumours contain Reinke crystals.