Ovarian tumors, or ovarian neoplasms, aretumors in theovary.^[1] Not all areovarian cancer.^[1] They consist of mainly solid tissue, whileovarian cysts contain fluid.^[2]

In 2020, theWorld Health Organization (WHO) divided ovarian tumours as 90% epithelial, 3% germ cell, and 2% sex cord-stromal types.^[3]

Tumor of the ovary vary remarkably as they may arise from any of the 3 cell types of the normal ovary.

Ovarian tumors are classified according to thehistology of the tumor, obtained in apathology report. Histology dictates many aspects of clinical treatment, management, andprognosis.

The most common forms are:

Type	Subtype	Relative incidence[5]	Percent malignant[5]	Comments	Micrograph
Germ cell tumor	Mature cysticteratoma	46.0%	0.17% to 2%[6]	Cystic, with elements of all 3germ layers (endoderm,mesoderm andectoderm).[7]
	Immature teratoma	2.5%	100%	Ateratoma that containsanaplastic immature elements, and is often synonymous withmalignant teratoma.[8]
	Other germ cell tumors	3.0%		Others mainly includedysgerminoma,yolk sac tumor,struma ovarii andsquamous cell carcinoma arising from a dermoid cyst, and malignant mixed germ cell tumor.[5]
Surface epithelial-stromal tumor	Serous tumor	25%	18.5%	Benign serous tumors of the right ovarian cyst are thinwalled unilocular cysts that are lined by ciliated pseudostratified cuboidal or columnar epithelium.[9]
	Mucinous tumor	15%	8.8%	Benign mucinous tumors of the ovary consist of simple, nonstratified columnar epithelium with basally-located hyperchromatic nuclei and resemble gastric foveolar epithelium.[9]
	Endometrioid tumor	1%	Almost 100%	Tubular glands, resembling endometrium.[10]
	Other surface-epithelial tumors	1.5%		Others include mainly malignant mixedMüllerian tumor,Brenner tumor and mixed epithelial tumor.[5]
Sex cord-stromal tumor	Ovarian fibroma	1.5%	0%	Spindle-shaped fibroblastic cells and abundant collagen.[11]
	Adultgranulosa cell tumor	1%	Almost 100%	Small, bland, cuboidal to polygonal cells in various patterns.[12]
	Other sex cord-stromal tumors	1%		Others include mainlyjuvenile granulosa cell tumor,thecoma andsclerosing stromal tumor[5]
Secondary/metastatic) tumor		2%	100%	Usually frombreast cancer,colon cancer,endometrial cancer,stomach cancer orcervical cancer.[13]

Mixed tumors contain elements of more than one of the above classes of tumor histology.

An 1882 article appearing inScientific American mentions the case of a patient atUniversity of Pennsylvania Hospital when Dr.William Goodell removed a 112 lbs tumor from a 31 year old patient, who weighted 75 lbs after removal from the tumor.^[14]

• International Ovarian Tumor Analysis trial

• Ovarian cancer

• Articles with short description
• Short description matches Wikidata