Chapter 1 - Histopathology of Gynaecological Cancer
Primary ETs are classified based on histological type and into benign, borderline (atypical, non-invasive) and malignant. Carcinomas represent a heterogeneous group of different diseases.
Some carcinomas follow a benign–adenoma–carcinoma morphological and molecular pathway in the ovary: they are frequently unilateral, low grade (in most cases), and show lower levels of genetic anomalies. Staging is prognostically relevant.
High-grade serous carcinomas are usually detected at high stage and no macroscopic residual disease after debulking is the main prognostic variable. All show p53 mutations and genetic instability; BRCA genes are involved in hereditary and in some sporadic cases.
Endometrioid and clear cell carcinomas may arise in endometriosis. Borderline tumours are rare and clinically benign, but can be found associated with carcinomas. Grading is relevant in endometrioid carcinomas.
Mucinous carcinomas usually develop within borderline tumours (otherwise clinically benign) and behaviour is dependent on the presence of invasion and high grade of atypia.
Serous borderline tumours can develop from inclusion cysts. They can present as Stage >1 and may recur. Invasive peritoneal implants are markers for progression and represent evolution into low-grade serous carcinoma, which may also develop in the ovary and peritoneum.
High-grade serous carcinomas are the most frequent carcinomas. Unlike previously thought, they often do not arise in the ovary. The distal Fallopian tube is the site of origin in BRCA patients and it is commonly involved in sporadic cases. Serous intraepithelial carcinoma (STIC) is considered the precursor lesion; however, it can already metastasise.
Revision Questions
- What is the most frequent and more frequently disseminated type of ovarian carcinoma?
- What are the most important prognostic variables in serous carcinomas?
- What is considered the main precursor of clear cell carcinoma of the ovary?