Ovarian epithelial tumors - benign & malignant. Germ cell and sex cord-stromal tumors. Classification.
Ovarian cancers are the 8th most common cancer in the developed world. There is a wide variety of cancers due to the presence of three cell types, multipotent surface epithelium, totipotent germ cells and sex cord-stromal cells, each of which give rise to different tumours. Let's take a look:
- Surface epithelial tumours
- Accounts for the vast majority of malignant ovarian tumours
- We have classifed these below:
- Serous tumours
- Benign or malignant (25% malignant e.g. serous cystadenocarcinoma)
- Include cystic and/or fibrous areas
- Lined by tall, columnar, ciliated epithelia, filled with serous fluid, involve surface of ovary
- Mucinous tumours
- Less likely to be bilateral than serous form, less common
- Characterised by more cysts of variable size
- Lined with tall columnar epithelial cells, no cilia
- Endometrioid tumours
- 20% of all ovarian cancers, mostly malignant (endometrioid carcinoma)
- Made of tubular glands
- Clear cell tumors
- Large epithelial cells with clear cytoplasm
- Seen in association with endometriomas or endometrioid carcinoma of ovary
- Brenner tumor
- Small cell tumors
- Germ cell tumours
- Account for 15-20% of all tumours, 5% of malignant
- Categories are based on histology, germinomatous tumours lack any form of histologic differentiation, while nongerminomatous germ cells display various differentiations:
- Germinomatous
- Germinoma (malignant)
- Dysgerminoma
- Seminoma (the testicular counterpart of dysgerminoma)
- Nongerminomatous
- Embryonal carcinoma
- Endodermal sinus tumor (yolk sac tumour)
- Choriocarcinoma
- Teratoma
- Mixed
- Sex Cord-Stromal
- Tumours derived from stromal component of ovaries (and testis), composed of granulosa, thecal cells and fibrocytes (basically, these are mesenchymal tumours)
- They come from Sex Cord, (in women these are the follicles), Gonadal stromal or can be mixed.
- The tumours are:
- In women: Granulosa cell tumour, Thecoma fibroma and sertoli-leydig cell tumour
- In men: sertoli cell tumour, leydig cell tumour and sertoli-leydig cell tumour
Gross: opened mature cystic teratoma (dermoid cyst) full of hair and greasy sebaceous material; the solid nodule in the wall is where hair, teeth or bone usually arise.
Image: “Mature Cystic Teratoma of the Ovary (5560431170)” by Ed Uthman from Houston, TX, USA, CC BY 2.0, via Wikimedia Commons.
Remember: one hallmark for several ovarian tumours:
- Psammoma bodies: serous carcinoma
- Call-Exner bodies: granulosa cell tumour (makes estrogen, so endometrial hyperplasia)
- Schiller-Duval bodies: yolk sac tumour (raised AFP)
- Hair, sebum and teeth: mature cystic teratoma (dermoid cyst), the commonest ovarian germ cell tumour, benign