Endometrial hyperplasia

See Endometrium for dating and benign pathologies.

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

The most widely used system is from the World Health Organization (WHO). The WHO system is based on determining:

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

WHO system

Simple endometrial hyperplasia

• Irregular gland shape.
• Variation of gland size.
• With or without atypia.
  • Most commonly seen without atypia.

Complex endometrial hyperplasia

• Increase in size & number of glands + irreg. shape.
  • Need cribriform architecture.
  • Two "touching" glands are likely one gland in section.
• Cell stratification.
• Nuclear enlargement.
• Mitoses common.
• May occur with atypia.

Notes:

• Normal gland-to-stroma ratio is 1:3.

Images:

• Endometrial hyperplasia (webpathology.com).
• Complex endometrial hyperplasia with atypia (webpathology.com).

Endometrial cancer vs. complex endometrial hyperplasia

• Complex endometrial hyperplasia: non-confluent (glands distinct from one another).
• Diagnosis of complex EH is based on histology (cytologic features).

Note: An alternative grading system from Harvard exists. It is not widely used. It defines a term called endometrial intraepithelial neoplasia (EIN).

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.

Endometrial carcinoma

Main article: Endometrial carcinoma

Endometrial hyperplasia (EH) is a risk for the development of endometrioid endometrial carcinoma.

Risk of progression to carcinoma

Approximate risk of progression to carcinoma:

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

See also

• Endometrium.
• Gynecologic pathology.