Histotype Grade Frequency (%) Pathogenesis Cell of origin Precursor lesion Common somatic mutations Type References
Brenner Low-grade <1 Stepwise FTE Benign Brenner tumor KRAS PIK3CA I [9,10]
Mucinous   5 Stepwise/ De novo Unknown Adenoma Mucinous Borderline tumor Teratoma Endometriosis BRAF KRAS RNF43 TP53 I [6,12]
Clear cell   5 Stepwise Endometrium Endometriosis Borderline tumor Adenofibroma ARID1A, KRAS, PIK3CA, PPP2R1A I [6,8]
Endometrioid Low-grade 10 Stepwise Endometrium Endometriosis Borderline tumor Adenofibroma CTNNB1 KRAS MLH2 MLH6 MSH1 PIK3CA PTEN I [6,13]
  High-grade   Stepwise Endometrium Endometriosis Borderline tumor Adenofibroma PPP2R1A TP53 II [6,13]
Serous Low-grade 5 Stepwise FTE Serous borderline tumor KRAS BRAF I [6,7]
  High-grade 70 De novo FTE Serous tubal intraepithelial carcinoma BRCA1 BRCA2 TP53 II [6,11,16]
Table 1: Principal histotypes of ovarian epithelial tumors.