Endometrioid tumors are a class of tumor characterized by a resemblance to

endometrium The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional laye ...

/ endometrial carcinoma, and over a third of cases have focal squamous differentiation.

Ovary

Incidence of ovarian cancers by histopathology

They are part of the surface epithelial tumor group of

ovarian neoplasm The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...

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 Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, f ...

and concurrent primary endometrial carcinoma (

endometrial cancer Endometrial cancer is a cancer that arises from the endometrium (the lining of the uterus or womb). It is the result of the abnormal growth of cells that have the ability to invade or spread to other parts of the body. The first sign is most o ...

). On gross 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.

Endometrium

Endometrioid carcinoma can also arise in the endometrium. Grades 1 and 2 are considered "type 1"

, while grade 3 is considered "type 2". File:Pie chart of relative incidences of endometrial carcinoma.png, Relative incidences of endometrial carcinomas by histopathology, being endometrioid in a majority of cases

Light microscopy

Light microscopy Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...

shows tubular glands, resembling endometrium.

Molecular biology

CTNNB1 and PTEN mutations

Ovarian and endometrial endometrioid carcinomas have distinct CTNNB1 and PTEN

gene mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitos ...

profiles. PTEN mutations are more frequent in low-grade endometrial endometrioid carcinomas (67%) compared with low-grade ovarian endometrioid carcinomas (17%). By contrast, CTNNB1 mutations are significantly different in low-grade ovarian endometrioid carcinomas (53%) compared with low-grade endometrial endometrioid carcinomas (28%). This difference in CTNNB1 mutation frequency may be reflective of the distinct

tumoral microenvironment A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s; the epithelial cells lining an

endometriotic cyst Endometriosis is a disease of the female reproductive system in which cells similar to those in the endometrium, the layer of tissue that normally covers the inside of the uterus, grow outside the uterus. Most often this is on the ovaries, fal ...

within the

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

are exposed to a highly oxidative environment that promotes tumorigenesis.

References

External links

{{DEFAULTSORT:Endometrioid Tumor Gynaecological cancer