- Human pathology

Home > E. Pathology by systems > Reproductive system > Female genital system > Uterus > endometrial hyperplasia without atypia

endometrial hyperplasia without atypia

Tuesday 17 January 2017

benign endometrial hyperplasia; non atypical endometrial hyperplasia; simple endometrial hyperplasia


Definition: Endometrial hyperplasia without atypia is a proliferation of endometrial glands of irregular size and shape without significant cytological atypia.

Simple hyperplasia without atypia is characterized by cystically dilated glands of various shapes and sizes. There is mild increase in gland-to-stroma ratio. Progression to adenocarcinoma occurs only in about 1% of cases.

Endometrial hyperplasia is the result of excessive estrogenic stimulation of the endometrium. Associated conditions include obesity, polycystic ovary disease (including Stein-Leventhal syndrome), functioning granulosa cell tumors of ovary, and exogenous estrogens etc.


- By definition, there is no cytologic atypia and no significant complexity (glandular confluence with loss of individual glandular contours, cribriform or microacinar architecture)

- Gland to stroma ratio is greater than 1:1 (glands occupy more than 50% of the surface area);

  • these areas of "gland crowding" still contain small amounts of stroma in between glands, and the individual glandular contours can be easily distinguished
  • Glands are usually round or elongated; however, shape and size irregularity are common including cystic dilation

- Lining epithelium usually displays proliferative-type morphology with pseudostratified or mildly stratified columnar cells containing elongated cigar shaped nuclei
- Metaplastic change (tubal, mucinous, squamous, secretory) can be seen
- Cellular stroma with variable mitotic activity, uniformly distributed blood vessels



See also

- endometrial hyperplasia