Editing Surface epithelial-stromal tumor (section)

==Classification==
[[File:Ovarian tumors by incidence and cancer risk.png|thumb|300px|[[Ovarian tumor]]s by [[Incidence (epidemiology)|incidence]] and risk of [[ovarian cancer]], with surface epithelial-stromal tumors at top.<ref>- {{cite journal|last1=Vaidya|first1=SA|last2=Kc|first2=S|last3=Sharma|first3=P|last4=Vaidya|first4=S|title=Spectrum of ovarian tumors in a referral hospital in Nepal|journal=Journal of Pathology of Nepal|volume=4|issue=7|year=2014|pages=539–543|issn=2091-0908|doi=10.3126/jpn.v4i7.10295|doi-access=free}}<br>- Minor adjustment for mature cystic teratomas (0.17 to 2% risk of ovarian cancer): {{cite journal|last1=Mandal|first1=Shramana|last2=Badhe|first2=Bhawana A.|title=Malignant Transformation in a Mature Teratoma with Metastatic Deposits in the Omentum: A Case Report|journal=Case Reports in Pathology|volume=2012|year=2012|pages=1–3|issn=2090-6781|doi=10.1155/2012/568062|pmid=23082264|pmc=3469088|doi-access=free}}</ref>]]
[[File:Incidence of ovarian cancers by histopathology.png|thumb|300px|Ovarian cancers in women aged 20+, with area representing relative incidence and color representing [[5-year relative survival rate]].<ref name=SEER6215ch16 /> ''Surface epithelial-stromal tumors'' are labeled in center of the main diagram, and represent all types except the ones separated at top.]]
Epithelial-stromal tumors are classified on the basis of the [[epithelial cell]] type, the relative amounts of epithelium and [[Stroma of ovary|stroma]], the presence of [[wiktionary:Papillary|papillary]] processes, and the location of the epithelial elements. [[Microscope|Microscopic]] [[pathology|pathological]] features determine whether a surface epithelial-stromal tumor is [[benign]], a [[borderline tumor]], or [[malignant]] (evidence of malignancy and stromal invasion). Borderline tumors are of uncertain malignant potential.

This group consists of [[serous tumor|serous]], [[mucinous tumor|mucinous]], [[endometrioid tumor|endometrioid]], [[clear cell adenocarcinoma|clear cell]], and [[brenner tumor|brenner]] (transitional cell) tumors, though there are a few mixed, undifferentiated and unclassified types.

===Serous tumors===
{{Main|Serous tumor}}
[[File:Histopathology of lining of a benign serous tumor of the ovary.jpg|thumb|Histopathology of lining of a benign serous tumor of the ovary. Benign serous ovarian tumors are thin walled unilocular cysts that are lined by ciliated pseudostratified cuboidal or columnar epithelium.<ref name=Baradwan2018/>]]
*These tumors vary in size from small and nearly imperceptible to large, filling the [[abdominal]] cavity.
*[[Benign]], [[borderline tumor|borderline]], and [[malignant]] types of serous tumors account for about 30% of all ovarian tumors.
*75% are benign or of borderline malignancy, and 25% are malignant
*The malignant form of this tumor, [[Cystadenocarcinoma|serous cystadenocarcinoma]], accounts for approximately 40% of all carcinomas of the ovary and are the most common malignant ovarian tumors.	
*Benign and borderline tumors are most common between the ages of 20 and 50 years.
*Malignant serous tumors occur later in life on average, although somewhat earlier in familial cases.
*20% of benign, 30% of borderline, and 66% of malignant tumors are bilateral (affect both ovaries).

Components can include:
#cystic areas
#cystic and fibrous areas
#predominantly fibrous areas

The chance of [[malignancy]] of the tumor increases with the amount of solid areas present, including both papillary structures and any necrotic tissue present.

====Pathology====
*lined by tall, columnar, [[ciliated]] [[epithelial]] cells
*filled with clear [[serous]] fluid
*the term [[serous]] which originated as a description of the [[cyst]] fluid has come to be describe the particular type of [[epithelial]] [[cell (biology)|cell]] seen in these tumors	
*may involve the surface of the ovary
*the division between benign, borderline, and malignant is ascertained by assessing:
**cellular atypia (whether or not individual cells look abnormal)
**invasion of surrounding ovarian stroma (whether or not cells are infiltrating surrounding tissue)
**[[borderline tumor]]s may have cellular atypia but do NOT have evidence of invasion
**the presence of [[psammoma body|psammoma bodies]] are a characteristic microscopic finding of cystadenocarcinomas<ref>{{cite book | last1 = Cotran | first1 = Ramzi S. | last2 = Kumar | first2 = Vinay | first3 = Fausto | last3 = Nelson | last4 = Robbins | first4 = Stanley L. | last5 = Abbas | first5 = Abul K. | name-list-style = vanc |title=Robbins and Cotran pathologic basis of disease |publisher=Elsevier Saunders |location=St. Louis, Mo |year=2005 |isbn=978-0-7216-0187-8 |edition=7th}}</ref>

====Prognosis====
The prognosis of a serous tumor, like most neoplasms, depends on 
*degree of differentiation
**this is how closely the tumor cells resemble benign cells
**a well-differentiated tumor closely resembles benign tumors
**a poorly differentiated tumor may not resemble the cell type of origin at all
**a moderately differentiated tumor usually resembles the cell type of origin, but appears frankly malignant
*extension of tumor to other structures
**in particular with serous malignancies, the presence of malignant spread to the peritoneum is important with regard to prognosis.

The [[five-year survival rate]] of [[borderline tumor]]s and malignant tumors confined to the ovaries are 100% and 70% respectively.  If the peritoneum is involved, these rates become 90% and 25%.

While the 5-year survival rates of borderline tumors are excellent, this should not be seen as evidence of cure, as recurrences can occur many years later.

===Mucinous tumors===
[[File:Histopathology of lining of a benign mucinous tumor of the ovary.jpg|thumb|Histopathology of lining of a benign mucinous tumor of the ovary. Benign mucinous ovarian tumors consist of simple, nonstratified columnar epithelium with basally-located hyperchromatic nuclei and resemble gastric foveolar epithelium.<ref name=Baradwan2018>{{cite journal|last1=Baradwan|first1=Saeed|last2=Alalyani|first2=Haneen|last3=Baradwan|first3=Amira|last4=Baradwan|first4=Afnan|last5=Al-Ghamdi|first5=Maram|last6=Alnemari|first6=Jameel|last7=Al-Jaroudi|first7=Dania|title=Bilateral ovarian masses with different histopathology in each ovary|journal=Clinical Case Reports|volume=6|issue=5|year=2018|pages=784–787|issn=2050-0904|doi=10.1002/ccr3.1466|pmid=29744056|pmc=5930217}}<br>- [https://creativecommons.org/licenses/by/4.0/ Creative Commons Attribution 4.0 International (CC BY 4.0) license]</ref>]]
[[Mucinous tumor]]s:
*Closely resemble their serous counterparts but unlikely to be bilateral
*Somewhat less common, accounting for about 25% of all ovarian neoplasms
* In some cases mucinous tumors are characterized by more cysts of variable size and a rarity of surface involvement as compared to serous tumors	
*Also in comparison to serous tumors, mucinous tumors are less frequently bilateral, approximately 5% of primary mucinous tumors are bilateral.
*May form very large cystic masses, with recorded weights exceeding 25&nbsp;kg

====Pathology====
Mucinous tumors are characterized by a lining of '''tall columnar epithelial cells''' with apical mucin and the absence of cilia, similar in appearance with benign cervical or intestinal epithelia.  The appearance can look similar to colonic or ovarian cancer, but typically originates from the appendix (see [[mucinous adenocarcinoma]] with clinical condition [[Pseudomyxoma peritonei]]). Clear stromal invasion is used to differentiate borderline tumors from malignant tumors.

====Prognosis====
10-year survival rates for [[borderline tumor]]s contained within the ovary, malignant tumors without invasion, and invasive malignant tumors are greater than 95%, 90%, and 66%, respectively. One rare but noteworthy condition associated with mucinous ovarian neoplasms is [[pseudomyxoma peritonei]]. As primary ovarian mucinous tumors are usually unilateral (in one ovary), the presentation of bilateral mucinous tumors requires exclusion of a non-ovarian origin, usually the appendix.

===Endometrioid tumors===
[[Endometrioid tumor]]s account for approximately 20% of all ovarian cancers and are mostly malignant (endometrioid carcinomas). They are made of tubular glands bearing a close resemblance to benign or malignant endometrium. 15-30% of endometrioid carcinomas occur in individuals with carcinoma of the endometrium, and these patients have a better prognosis. They appear similar to other surface epithelial-stromal tumors, with solid and cystic areas. 40% of these tumors are bilateral, when bilateral, metastases is often present.

====Pathology====
*Glands bearing a strong resemblance to endometrial-type glands
**Benign tumors have mature-appearing glands in a fibrous stroma
**Borderline tumors have a complex branching pattern without stromal invasion
**Carcinomas (malignant tumors) have invasive glands with crowded, atypical cells, frequent mitoses.  With poorer differentiation, the tumor becomes more solid.

====Prognosis====
Prognosis again is dependent on the spread of the tumor, as well as how differentiated the tumor appears.  The overall prognosis is somewhat worse than for serous or mucinous tumors, and the 5-year survival rate for patients with tumors confined to the ovary is approximately 75%.

===Clear cell tumors===
[[File:Ovarian clear cell carcinoma -a- very high mag - cropped.jpg|thumb|right|[[Micrograph]] of an ovarian clear cell carcinoma. [[H&E stain]].]]
[[Clear cell adenocarcinoma|Clear cell tumor]]s are characterized by large epithelial cells with abundant clear cytoplasm	and may be seen in association with endometriosis or endometrioid carcinoma of the ovary, bearing a resemblance to clear cell carcinoma of the endometrium. They may be predominantly solid or cystic. If solid, the clear cells tend to be arranged in sheets or tubules. In the cystic variety, the neoplastic cells make up the cyst lining.

====Prognosis====
These tumors tend to be aggressive, the five year survival rate for tumors confined to the ovaries is approximately 65%.  If the tumor has spread beyond the ovary at diagnosis, the prognosis is poor

===Brenner tumor===
[[File:Brenner tumour4.jpg|thumb|right|[[Brenner tumour]]. [[H&E stain]].]]
[[Brenner tumor]]s are uncommon surface-epithelial stromal cell tumors in which the epithelial cell (which defines these tumors) is a transitional cell.  These are similar in appearance to bladder epithelia.  The tumors may be very small to very large, and may be solid or cystic.  Histologically, the tumor consists of nests of the aforementioned transitional cells within surrounding tissue that resembles normal ovary.  Brenner tumors may be benign or malignant, depending on whether the tumor cells invade the surrounding tissue.

===Small cell tumors===
[http://www.sc-ovca.org/ Small cell ovarian cancer (SCCO)] are generally classified into epithelial tumors<ref>[http://atlasgeneticsoncology.org/Tumors/OvaryEpithTumID5230.html Atlas of Genetics and Cytogenetics in Oncology and Haematology - Ovary: Epithelial tumors]. Retrieved June 2014. By Lee-Jones, L. Atlas Genet Cytogenet Oncol Haematol. 2004;8(2):115-133.</ref> associated with distinctive endocrine features.<ref name=":0">{{Cite book|title=Small Cell and Neuroendocrine Cancers of the Ovary|last1=Kaphan|first1=Ariel A.|last2=Castro|first2=Cesar M. | name-list-style = vanc |date=2014-01-01|publisher=John Wiley & Sons, Ltd|isbn=9781118655344|editor-last=MPH|editor-first=rcela G. del Carmen MD |pages=139–147 |language=en |doi=10.1002/9781118655344.ch12 |editor-last2=FRCPATH|editor-first2=Robert H. Young MD|editor-last3=MD|editor-first3=John O. Schorge|editor-last4=MD|editor-first4=Michael J. Birrer}}</ref>

The World Health Organisation (WHO) recognises SCCO as two distinct entities: [http://www.sc-ovca.org/ Small Cell Ovarian Cancer of Hypercalcemic Type (SCCOHT)] and Small Cell Ovarian Cancer of Pulmonary Type (SCCOPT).<ref name=":0" />

Small cell tumours are rare and aggressive, they contribute to less than 2% of all gynaecologic malignancies.<ref name=":0" /> The average age of diagnosis is 24 years old, and the majority of patients also present with hypercalcemia (62%).<ref name="BakhruLiu2012">{{cite journal | vauthors = Bakhru A, Liu JR, Lagstein A | title = A case of small cell carcinoma of the ovary hypercalcemic variant in a teenager | journal = Gynecologic Oncology Case Reports | volume = 2 | issue = 4 | pages = 139–42 | year = 2012 | pmid = 24371647 | pmc = 3861231 | doi = 10.1016/j.gynor.2012.09.001 }}</ref> It typically present with a unilateral large tumor.<ref name="BakhruLiu2012" /> Most women die within a year of diagnosis.<ref name="BakhruLiu2012" />