Table 1.
Common Precursor Lesions and Molecular Features of Type I and Type II Carcinomas
| Type I tumors | Common Precursors | Most Frequent Mutations | Chromosomal Instability (CIN)a |
|---|---|---|---|
| Low-grade serous CAb | Serous borderline tumor | KRAS, BRAF | Low |
| Low-grade endometrioid CA | Endometriosis | CTNNB1, PTEN | Low |
| Most clear cell CAc | Endometriosis | PIK3CA | Low |
| Mucinous CA | Mucinous borderline tumor | KRAS | Low |
| Type II tumors | |||
| High-grade serous CA | Not recognizedd | TP53 | High |
| High-grade endometrioid CA | Not recognized | TP53 | High |
| Clear cell CAc | Not recognized | ? | ? |
| Undifferentiated CA | Not recognized | ? | ? |
| Carcinosarcoma | Not recognized | TP53 | ? |
a
Low vs. High chromosomal instability (CIN) refers to comparison between low-grade and high-grade carcinomas within same histologic type
b
CA: Carcinoma
c
Criteria for classification of clear cell CA subsets into Type I vs. Type II categories are uncertain. It is thought that most clear cell carcinomas behave like Type I tumors while some clear cell carcinomas, presumably high-grade, may be Type II tumors.
d
Some high-grade serous CAs may be associated with tubal intraepithelial serous carcinoma