. Author manuscript; available in PMC: 2020 Aug 19.

Published in final edited form as: Cancer. 2019 Dec 15;125(Suppl 24):4623–4629. doi: 10.1002/cncr.32544

TABLE 2.

Major Morphologic Types of Ovarian, Tubal, and Peritoneal Cancer

Type	Percent of Total	Molecular Characteristics	Clinical Characteristics
High-grade serous	70%	TP53^mut, PIK3CA^mut Copy number variability	Serous tubular in situ carcinoma² precursor; primary type in peritoneal carcinoma
Low-grade serous	3.5%	Approximately 50% KRAS^mut and approximately 20% BRAF^mut	Precursor is serous borderline cancer Frequent psammoma bodies
Clear cell	10%	ARID1a^mut, PIK3CA^mut, PIK3CA^amp	Endometriosis can transition into clear cell
Endometrioid high grade	10%	ARID1a^mut, PIK3CA^mut, PTEN LOH, β-catenin^mut	Can have borderline cancer precursor; some relationship to endometriosis
Endometrioid low grade		TP53^mut	Recategorized with high-grade serous
Mucinous	3.6%	80%⁺ KRAS^mut	Intestinal type only; some question regarding whether this is observed only in borderline and early-stage disease; late stage presentation most commonly not ovarian primary tumor

Abbreviations: amp, amplification; LOH, loss of heterozygosity; mut, mutation.