Editing Endometrioid tumor (section)

==Ovary==
[[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>{{Cite book|contribution=Chapter 16: Cancers of the Ovary|first=Carol L.|last=Kosary|pages=133–144|publisher=National Cancer Institute|title=SEER Survival Monograph: Cancer Survival Among Adults: US SEER Program, 1988-2001, Patient and Tumor Characteristics|editor1-last=Baguio|editor1-first=RNL|editor2-last=Young|editor2-first=JL|editor3-last=Keel|editor3-first=GE|editor4-last=Eisner|editor4-first=MP|editor5-last=Lin|editor5-first=YD|editor6-last=Horner|editor6-first=M-J|series=SEER Program|volume=NIH Pub. No. 07-6215|place=Bethesda, MD|year=2007|chapter-url=http://seer.cancer.gov/publications/survival/surv_ovary.pdf|url=http://seer.cancer.gov/publications/survival/}}</ref> ''Endometrioid tumor'' is labeled at bottom left.]]
Ovarian endometrioid tumors are part of the [[surface epithelial-stromal tumor|surface epithelial]] [[tumor]] group of [[Ovarian cancer|ovarian neoplasm]]s (10–20% of which are the endometrioid type).
[[Benign]] and borderline variants are rare, as the majority are [[malignant]].
There is an association with [[endometriosis]] and concurrent primary [[endometrial carcinoma]] ([[endometrial cancer]]).

On gross [[pathology|pathological]] examination, the tumor is cystic and may be solid and some arise in cystic endometriosis. In 40% of cases, endometrioid tumors are found bilaterally.<ref>{{cite book |editor1-last=Robbins |editor2-last=Cotran |title=Pathologic Basis of Disease |location=Philadelphia |publisher=Saunders |edition=7th |isbn=978-0-7216-0187-8 |year=2005 }}</ref>