Chapter 1 - Histopathology of Gynaecological Cancers
Ovarian tumours are classified based on cell types, patterns of growth and, whenever possible, on histogenesis (WHO Classification 2014).
There are 3 major categories of primary ovarian tumour: epithelial tumours (ETs), sex cord–stromal tumours (SCSTs) and germ cell tumours (GCTs). Secondary tumours are not infrequent.
The incidence of malignant forms varies with age. Carcinomas, accounting for over 80%, peak at the 6th decade; SCSTs peak in the perimenopausal period; GCTs peak in the first three decades. Prognosis is worse for carcinomas.
The staging classification has been recently revised (FIGO 2013 Classification) and ovarian, Fallopian tube and peritoneal cancer are classified together.
Stage I cancer is confined to the ovaries or Fallopian tubes. Peritoneal cytology/washing, tumour rupture or surface involvement warrants a Stage IC.
In Stage II, the disease involves one or both ovaries/ Fallopian tubes with extension to the pelvis below the pelvic brim (note: peritoneal cancer has no FIGO Stage I).
Most patients with ETs present at high stage (III-IV). In Stage III, the disease involves one or both adnexae and spread to the pelvic and abdominal peritoneum and/or retroperitoneal lymph nodes.
Stage IV includes patients with pleural diffusion and intraparenchymal liver/spleen or extra-abdominal metastases or extra-abdominal lymph nodes (LNs).
The revised FIGO staging system better reflects the prognosis of patients with ovarian cancer and LN metastases.
Revision Questions
- How many categories of ovarian tumour can be classified?
- If the disease is on the bladder peritoneum, is the patient staged as Stage IIA or IIB?
- If the disease involves the abdominal peritoneum and mediastinal LNs, is the patient staged as Stage IIIC or IVB?