Endometrial hyperplasia

See Endometrium for an introduction to the topic.

Endometrial hyperplasia, abbreviated EH, is a precursor to endometrial carcinoma.

Overview

The most widely used system is from the World Health Organization (WHO).

WHO endometrial hyperplasia classification of 1994 - overview

The WHO system of 1994 is based on determining:

1. Gland density (normal = simple hyperplasia, high density = complex hyperplasia).
2. Presence/absence of nuclear atypia.

Alternate classifications - overview

Two alternative grading systems exist, that are (currently) not widely used:

1. European group of experts (1999).
2. Endometrial collaborative group/Harvard (2000).

Both consist of two categories, as opposed to four found in the WHO classification.

European group of experts classification

1. Endometrial hyperplasia.
2. Endometrioid neoplasia.

Endometrial collaborative group/Harvard classification

1. Endometrial hyperplasia.
2. Endometrial intraepithelial neoplasia (EIN).

WHO classification

Management of endometrial hyperplasia

• Endometrial hyperplasia with atypia is usually treated with hysterectomy.
  • In women who want to maintain fertility it may be treated with progestin + short interval re-biopsies (q3 months).
• Endometrial hyperplasia without atypia is treated by:
  • Progestins + close follow-up OR hysterectomy.

Risk of progression to carcinoma as per 1994 system

Approximate risk of progression to endometrial carcinoma - Latta rule of 3s:

	Simple	Complex
Without atypia	1%	3%
With atypia	9% †	27% ‡

Notes:

• † 8% is the true number.
• ‡ 29% is the true number.

Ki-67

There is one paper that looks at Ki-67:

Diagnosis	Percent positive
Secretory phase endometrium	15%
Proliferative phase endometrium	42%
Simple hyperplasia	26%
Simple hyperplasia with atypia	23%
Complex hyperplasia	16%
Complex hyperplasia with atypia	42%

WHO system of 1994

Almost all hyperplasia is seen in the context of proliferative-type endometrium. Hyperplasia in the secretory-type endometrium is extremely rare and something diagnosed by or in consultation with an expert in gynecologic pathology.

Simple endometrial hyperplasia

• AKA simple hyperplasia.

Main article: Simple endometrial hyperplasia

Simple endometrial hyperplasia with atypia

Main article: Simple endometrial hyperplasia

Complex endometrial hyperplasia

• Abbreviated CEH.

Main article: Complex endometrial hyperplasia

Complex endometrial hyperplasia with atypia

• AKA complex atypical hyperplasia.

Main article: Complex endometrial hyperplasia

WHO system of 2014

The 2014 WHO system only has two categories:

• Hyperplasia without atypia.
• Atypical hyperplasia/endometrioid intraepithelial neoplasia.

Note:

• The newer WHO system dispenses with the terms simple and complex.

Other

Endometrial hyperplasia with secretory changes

General

• Rare.
• Secretory changes seen in 1-2% of endometrial hyperplasias/endometrial carcinomas.

Microscopic

Features:

• Secretory changes - includes at least one of three following:
  1. Stromal decidualization.
  2. Cytoplasmic vacuolization.
  3. Intraluminal secretions.
• Proliferative-type epithelium. †
  • Mitoses.
  • Nuclear atypia.
  • Pseudostratified epithelium.

Notes:

• † This is not precisely defined. I suppose it is some of the things Bell and Ostrezega mention (mitoses, nuclear atypia, pseudostratified epithelium).
  • Bell and Ostrezega give a laundry list for differentiating benign secretory endometrium from hyperplasia with secretory changes: focal architectural abnormalities, metaplastic ciliated & "clear" cells, sharp luminal border, epithelial pseudopalisading, nuclear atypia, vesicular nuclei, mitoses.

DDx:

• Secretory phase endometrium.
• Endometrium with hormonal changes.

Images:

• Endometrial hyperplasia with secretory changes (cap.org).

See also

• Endometrium.
• Endometrial carcinoma.
• Gynecologic pathology.