Pathology Outlines - Endometrial hyperplasia

Uterus
Endometrial hyperplasia
General

Author: Carlos Parra-Herran, M.D. (see Authors page)

Revised: 17 January 2018, last major update August 2016

Copyright: (c) 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Endometrial hyperplasia [title]

Table of Contents

Cite this page: Endometrial hyperplasia - General. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/uterusendometrialhyperplasiageneral.html. Accessed August 17th, 2018.

Definition / general

Definition: Proliferation of endometrial glands with an increase in the gland to stroma ratio compared to proliferative endometrium (> 1:1, glands represent more than 50% of the surface area)
The term "endometrial hyperplasia" includes lesions ranging from reversible glandular proliferations to direct cancer precursors (Semin Diagn Pathol 2010;27:199)
Incidence: simple - 142 / 100,000 woman-years, complex - 213 / 100,000 woman-years (both in the early 50s); atypical - 56 / 100,000 woman-years (in early 60s) (Am J Obstet Gynecol 2009;200:678)
Comparing curettage to subsequent hysterectomy, false positive rate of 1.8% and false negative rate of 13.2%; less accurate if use Pipelle endometrial sampler (Eur J Obstet Gynecol Reprod Biol 2011;159:172)
Previously classified based on WHO as simple vs complex, nonatypical vs atypical or EIN systems (J Gynecol Oncol 2010;21:97) - current WHO classification incorporates both systems and simplifies the terminology
Previous WHO system (endometrial hyperplasia) suffers from poor diagnostic reproducibility (Am J Surg Pathol 2008;32:691)

Etiology

Prolonged estrogenic stimulation with reduced progestational activity (usually near menopause or associated with anovulatory cycles)
Polycystic ovarian disease (Stein-Leventhal syndrome)
Ovarian granulosa cell tumors (functional)
Ovarian cortical stromal hyperplasia
Estrogen replacement therapy without progestational agents (Ann Epidemiol 2009;19:1)
Also associated with higher body mass index and obesity (J Reprod Med 2011;56:110)
Progression from normal to simple to complex hyperplasia associated with reduced levels of von Hippel-Lindau mRNA and protein (Int J Gynecol Cancer 2011;21:430)

Diagrams / tables

Images hosted on PathOut servers:

Courtesy of Dr. Carlos Parra-Herran

Prognostic factors

Usual predecessor to endometrial carcinoma, particularly younger women or those with well differentiated endometrioid adenocarcinoma, although most with hyperplasia do NOT develop carcinoma
Risk of developing carcinoma is greater with atypical hyperplasia and EIN
For nonatypical endometrial hyperplasia, risk was 1.2% at 4 years, 1.9% at 9 years, 4.6% at 19 years after diagnosis; for atypical hyperplasia, risk was 8.2% at 4 years, 12.4% at 9 years, 27.5% at 19 years (J Clin Oncol 2010;28:788)
Focal gland crowding, that does not fulfill all criteria for EIN, carries substantial risk of EIN and occasionally malignancy (Mod Pathol 2010;23:1486)

Treatment

Benign (nonatypical) endometrial hyperplasia: progestins or Levonorgestrel Intrauterine System / LNG-IUS (Jpn J Clin Oncol 2011;41:817)
Endometroid intraepithelial neoplasia / atypical hyperplasia: hysterectomy is the standard of care; progestins or LNG-IUS in candidates for fertility sparing treatment

Gross description