Table 1.

Histological classification of ovarian tumours adapted from WHO

Primary tumours (95 %)	Surface epithelial-stromal tumours (65 %)	serous	benign	cystadenoma, papillarycystadenoma adenofibroma/cystadenofibroma
			borderline	papillary cystic tumour, surface papillary tumour, adenofibroma/cystadenofibroma
			malignant	adenocarcinoma, surfacepapillary adenocarcinoma, adenocarcinomafibroma
		mucinous	benign	cystadenoma, adenofibroma/cystadenofibroma
			borderline	intestinal type, endocervical-like
			malignant	adenocarcinoma, adenocarcinomafibroma
		endometrioid
		clear cell
		transitional cell (Brenner)
		undifferentiated and unclassified
	Germ cell tumours (15 %)	teratoma	biphasic or triphasic	mature
				immature
			monodermal	strumaovarii
		dysgerminoma
		Yolk sac tumour
		choriocarcinoma
		embrionalcell carcinoma
	Sex cord-stromal (10 %)	granulosa cell	adult
			juvenile
		thecoma-fibroma group	fibroma
			techoma
			sclerosing stromal tumour
			unclassified (fibrothecoma)
		Sertoli-Leydigcell
		steroidcell
	Miscellaneous (5 %)	small cell carcinoma, gestational choriocarcinoma, others
Secondary tumours (5 %)		stomach, colon, breast, lung, contralateral ovary