Ultrasonographic features of endometrium in pre- and postmenopausal women

C. Tracy Suit, MDCornelia de Riese, MDSamuel Prien, PhDKelsey Kelso, BS

Background

The endometrium is a dynamic tissue Menstrual cycle Postmenopausal Exogenous hormones

Transvaginal US

Non-invasive Relatively inexpensive Good safety profile Readily available

Normal endometrium

Menstrual phase Days 1-5 <4 mm

Proliferative phase Days 6-14 4-8 mm

Secretory phase Days 14+ Up to 16 mm

Normal endometrium

In the follicular phase, the endometrium becomes relatively hypodense

As the cycle progresses the endometrium becomes more hyperechoic

Normal endometrium

Ovulatory period = trilaminar endometrium Echogenic basal layer Hypoechogenic functional layer Echogenic line

Usually disappears 48 hours after ovulation

Normal endometrium

Postmenopausal women Averages < 5 mm If on exogenous hormones, < 8 mm is

considered normal A small amount of fluid may be

considered normal

Premenopausal—Differential Diagnosis

Often due to normal proliferation under hormonal influences

Can include: Polyps Polypoid growths Hyperplasia or cancer Submucosal fibroids

Postmenopausal

Important distinction: symptoms Exogenous hormones

Postmenopausal—differential diagnosis

Polyps Hyperplasia or cancer Fibroids

Associated sonographic findings

Polyps: cystic spaces Hyperplasia: regular/homogeneous

echotexture Cancer: irregular margins, indistinct

borders between the endometrium and myometrium, heterogeneous echotexture, complex fluid

Study objective

To evaluate the predictive value of endometrial thickness and descriptive sonographic appearance on pathology in pre- and postmenopausal women

Methods

1903 gynecologic ultrasounds of the endometrium were performed between January, 2004 and January 2009

Stratification: Of these, 367 had pathology performed within 3 months of the ultrasound

The patients were then divided into either pre- or post menopausal after review of the chart

Methods

Each US was critically evaluated for: Endometrial thickness Descriptors of the endometrium

Hyper- or hypoechoic Heterogeneous Regular or irregular Ill-defined Secretory Presence of polyps, fluid or fibroids

Exclusion criteria

No corresponding pathology (EMB, curettage, or hysterectomy) within 3 months of the US

No measurement of the endometrial thickness or distortion by fibroids so that the endometrium could not be meaningfully evaluated

Patient less than 18 years old

Methods

Pathology was classified into groups: Benign: proliferative or secretory,

atrophic, or chronic endometritis Precancerous or cancerous: simple

hyperplasia with or without atypia, complex hyperplasia with or without atypia, endometrial cancer

Statistics

Endometrial descriptors were compared with pathology using a Chi-Square analysis

Endometrial thickness and age were compared using a Student’s t-test

Results

Overall: N=367 Postmenopausal group: N=76

Benign: 69 PreCA/CA: 7

Premenopausal group: N=291 Benign: 267 PreCA/CA: 24

Result: Postmenopausal group

Of the 7 women with pathologic findings: 1 with complex hyperplasia without atypia 6 women with cancer

Average endometrial thickness 20.3 mm Range 13.63 mm to 37 mm

Results: Postmenopausal group

Age Benign: 54 PreCA/CA: 62 There was a trend toward older age with

precancer or cancer Endometrial thickness

Benign: 9.7 mm PreCA/CA : 17.9 mm p<0.05

Results: Postmenopausal group

Descriptive terms No difference between groups

Results: Postmenopausal group

Results: Premenopausal group

Of the women with preCA/CA: 18 with simple hyperplasia

Ranged from 1 mm to 29 mm Average endometrial thickness 11.6 mm

6 with endometrial cancer Average endometrial thickness 24 mm

Results: Premenopausal group

Age: Benign: 39 preCA/CA: 43 Trend toward older age with diagnosis of

hyperplasia or cancer Endometrial thickness:

Benign: 8.9 mm preCA/CA: 15.0 p<0.01

Results: Premenopausal group

Descriptive terms If the endometrial stripe was described as

heterogeneous or irregular, the patients were significantly more likely to have hyperplasia or cancer (p<0.01)

Results: Premenopausal women

Conclusions

Confirmed that endometrial thickness is increased in pathological conditions such as hyperplasia and cancer

But hyperplasia was diagnosed often within the “normal” ranges, especially in the premenopausal women

Conclusions

In the postmenopausal group, complex hyperplasia and cancer were diagnosed with an endometrial thickness of 3 and 5 mm, respectively

Conclusions

In premenopausal women, the average endometrial thickness in women with pathology was still in the normal range for secretory endometrium

Conclusions

In addition, no simple hyperplasia was diagnosed in the postmenopausal group—when pathology was found, it was much more likely to have become frank cancer

Conclusions

Heterogeneity and irregularity in echo pattern were significantly more likely to be associated with hyperplasia or cancer in the premenopausal group. It may have not reached significance in the postmenopausal women due to the smaller sample size.

Conclusions

One weakness of the study is the low rate of pathology

Conclusions

DO THE EMB in symptomatic women High risk women – even very young Postmenopausal women

OUTLOOK

What can the sonohysterogram add? We need to correlate findings to

ethnicity, metabolic and exogenous as well as endogenous hormonal influences to further define high risk scenarios.