Vaginal endosonography in endometrial cancer

Ultrasonic assessment of the postmenopausal uterus

OBJECTIVES

To assess the role of different forms of ultrasound in the evaluation of peri- and postmenopausal uterus.

METHODS

B-mode ultrasound, colour and pulsed Doppler sonography, three-dimensional ultrasound and three-dimensional power Doppler sonography are non-invasive tools used repeatedly for assessing morphology and vascularity of the uterus and uterine lesions in peri- and postmenopausal patients.

RESULTS

The application of transvaginal colour Doppler to the peri- and postmenopausal patients for the screening for endometrial and myometrial malignancy may be a viable option if combined with ovarian screening in the same scan. In this way the capital costs would be shared and oncological preventive medicine for postmenopausal women could be initiated. Three-dimensional and power Doppler ultrasound offers improved visualisation of uterine lesions, displays an entire volume, offers accurate volume estimation and enables retrospective review of stored data. Interactive rotation of power Doppler rendered images provides improved visualisation of the uterine vasculature.

CONCLUSIONS

Further technological development of the ultrasound imaging techniques could result in reduction of both the potential risks and economic cost of the invasive diagnostic procedures in postmenopausal patients such as dilatation and curettage operations. Same techniques can be used for early detection of endometrial malignancy in asymptomatic postmenopausal women as well as for prediction of the depth of myometrial invasion.

Use of transvaginal sonography in the evaluation of endometrial hyperplasia and carcinoma

Published studies relating to the use of transvaginal sonography (TVS) in the evaluation of endometrial hyperplasia and carcinoma were reviewed. Approximately 80 percent of all curettage procedures performed for postmenopausal bleeding result in benign diagnoses, therefore, if a noninvasive modality such as TVS can be accurately used to determine endometrial thickness measurements below which pathology is less likely, sampling may be avoided. The largest study evaluating endometrial measurements in postmenopausal women with bleeding, known as the Nordic trial, found that for a cut-off value of < or = 4 mm, 96 percent sensitivity and 68 percent specificity was achieved. Another study evaluated endometrial echomorphology in addition to measurement and found that the combined approach improved the predictability of pathologic findings. TVS may also be used to assess the depth of myometrial invasion in patients already diagnosed histologically with endometrial carcinoma. Although MRI is considered the established tool in the presurgical evaluation of the patient with carcinoma, TVS was found to perform only slightly less accurately than MRI. The published studies regarding TVS and/or MRI are reviewed. Finally, the use of TVS in conjunction with a new modality, sonohysterography, in the evaluation of patients on tamoxifen therapy, is discussed. Although the published cut-off values for endometrial thickness measurements do not apply to this group of patients, a procedure whereby sterile saline is injected into the uterine cavity, via a thin catheter, provides additional information regarding endometrial contours. Once the procedure is performed, the supposed complex endometrial echo seen on TVS is often found to actually be located in the subendometrial myometrium and the endometrium itself is thin and regular. The role for TVS is well established in the search for endometrial hyperplasia and carcinoma, as well as evaluating the presence of myometrial invasion once the diagnosis is made.

Transvaginal sonography of the endometrium in women with postmenopausal bleeding

OBJECTIVE

The purpose of this study was to determine the value of screening transvaginal ultrasonography for the evaluation of endometrial abnormalities in women with postmenopausal bleeding.

MATERIALS AND METHODS

250 women with postmenopausal bleeding underwent transvaginal ultrasonographic examinations before undergoing dilatation and curettage. Women who had any pelvic symptoms or were on hormone replacement therapy were excluded.

RESULTS

In 151 women, the histologic diagnosis was atrophic endometrium. In these patients, the mean endometrial thickness was 3.4 +/- 1.2 mm. In 24 patients with endometrial carcinoma, the mean endometrial thickness was 16.5 +/- 6.2 mm. The measurement included both endometrial layers (i.e. double layer). Thirty six cases of other pelvic pathologic conditions were discovered on ultra sonography.

CONCLUSIONS

We believe that is reasonable to have a cutoff limit for normal postmenopausal endometrium at 5 mm. Endovaginal ultrasound is a valuable diagnostic instrument, as sensitive as dilatation and curettage, for detecting pathological conditions in the uterine mucosa.

Virulence factors in endometrial cancer

The majority of endometrial cancers are relatively benign and curable; there is a subset of virulent tumors that demands recognition. Factors that must be evaluated include: tumor grade, ploidy, steroid receptors, myometrial invasion, lymph node status, extrauterine disease or positive peritoneal fluid, and certain special tumors. These tumors of special virulence include: papillary adenocarcinoma, papillary serous adenocarcinoma, adenosquamous carcinoma, and clear cell carcinoma. Virulent tumors (approximately 20%) require special consideration and special treatment.

Endometrial carcinoma: transvaginal ultrasonography prediction of depth of myometrial invasion

Myometrial invasion greater than 33% negatively affects the prognosis of endometrial carcinoma. Since the endometrium is readily differentiated from myometrium via high-resolution transvaginal sonography (TVS), this prospective study was undertaken to evaluate the efficacy of TVS in determining the depth of myometrial invasion in women with endometrial adenocarcinoma. Eighteen subjects underwent TVS utilizing 5.0- and 7.5-MHz probes by a single examiner blinded to stage and grade of adenocarcinoma. Predicted TVS ratios were categorized as less than 33% or greater than or equal to 33% and compared to actual histologic invasion. Ultrasound predicted that TVS ratios greater than or equal to 33% are significantly associated with deep (greater than 33%) histologic invasion (P less than 0.01, Fisher's test). When histologic invasion was greater than or equal to 33%, TVS was 100% accurate with no false negatives. The two cases in which TVS ratios erroneously indicated invasion greater than or equal to 33% contained adenomyosis and leiomyomas. TVS is a highly accurate and convenient method for preoperatively evaluating myometrial invasion. Potentially this evaluation could influence the selection of therapy for poor-surgical-risk candidates or direct appropriate referral of patients with deeper invasion to a gynecologic oncologist.

Endometrial thickness as measured by endovaginal ultrasonography for identifying endometrial abnormality

Diagnostic curettage has for many years been the method of choice to diagnose endometrial cancer in women with postmenopausal bleeding. The costs for curettage performed today are huge, and approximately only 10% in this group of women will be diagnosed with endometrial cancer. Thus less expansive techniques to obtain endometrial samples have been evaluated, but all of them are invasive. The value of endovaginal ultrasonography for identifying endometrial abnormality in this group of women has not been evaluated until now. This study used endometrial thickness as measured by endovaginal ultrasonography as an indicator of endometrial abnormality. It was demonstrated in 205 women with postmenopausal bleeding that if the endometrium was less than 9 mm thick, no endometrial cancer was found at curettage. The mean endometrial thickness in those women with endometrial cancer was 18.2 +/- 6.2 mm as compared with 3.4 +/- 1.2 mm in those women with atrophic endometrium. If the cutoff limit for endometrial abnormality was 5 mm, the positive predictive value for identifying endometrial abnormality was 87.3%. If this limit had been used in this study, 70% of the curettage procedures could have been avoided.

Depth of myometrial invasion in endometrial cancer: preoperative assessment by transvaginal ultrasonography

Twenty-five patients with cancer of the uterus underwent transvaginal sonography (TVS) to assess depth of myometrial invasion. All scans were performed with a 5.0-MHz curvilinear array probe (Toshiba, Inc., Tustin, CA) within 1 week of hysterectomy. In 21 cases (84%) sonography correctly predicted the depth of invasion (within 15% of actual). Only one of three cases with cervical involvement was detected. Transvaginal sonography can accurately detect depth of myometrial invasion and is well suited as a screening test to detect high-risk patients for consultation or referral.