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Archived Issues of Radiology Rounds
MGH Department of Radiology Website
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Ultrasound in the Evaluation of Abnormal Vaginal Bleeding
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- Bleeding in post-menopausal women is abnormal and is the most common presenting symptom for
endometrial cancer
- Nearly all endometrial cancer (96%) is associated with a thickened endometrium
(>4mm in post-menopausal women), which can be measured by transvaginal ultrasonography
- Saline infusion sonohysterography is a sensitive technique for the detection of focal lesions but
does not provide histological data
- Gynecologists recommend that the imaging work-up of abnormal bleeding in post-menopausal
women should always be supplemented with histological information
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Although
most abnormal vaginal bleeding is caused by hormone imbalance, it can
be indicative of disease including polyps, myomas, endometrial
hyperplasia, and cancers of the cervix and endometrium. In
post-menopausal women, the greatest concern is endometrial cancer,
which is now the most common gynecological cancer. Therefore, it is
important to determine the cause of all cases of post-menopausal
vaginal bleeding. More than 90% of the cases of endometrial cancer
occur in women over 50 and this disease accounts for approximately 10%
of the cases of vaginal bleeding in post-menopausal women.
Post-Menopausal Bleeding
Transvaginal Ultrasound (TVUS)
The
first step in evaluation post-menopausal bleeding may be a TVUS or an
endometrial biopsy. Although TVUS is the least sensitive and specific
examination for the diagnosis of cancer, it is more sensitive than
biopsy for the detection of other abnormalities, such as polyps and
fibroids, that are more commonly the cause of bleeding. It is also the
least invasive method and results in little or no discomfort for most
patients. Endometrial cancer causes the endometrium to thicken, which
appears as a thickened hyperechoic stripe in transvaginal US images.
The thickness of the endometrial stripe can be measured accurately and
it has been estimated that 96% of post-menopausal women with
endometrial cancer will have an endometrial stripe greater than 4 mm.
At this threshold the false positive rate is 50%. TVUS can also show if
the endometrial lining is very thin. If so, the bleeding may be due to
endometrial atrophy.
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Causes of Vaginal Bleeding in
Post-Menopausal Women
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| Polyps |
30% |
| Sub-mucosal fibroids |
30% |
| Endometrial atrophy |
8% |
| Hyperplasia |
4-8% |
| Endometrial carcinoma |
10% |
Women who are being treated with tamoxifen are at increased risk of
developing endometrial cancer but TVUS can be misleading in these
patients. Tamoxifen can cause sub-endometrial cyst development, which
makes the endometrium appear thickened in transvaginal sonograms.
However, the sub-endometrial cystic tissue can be differentiated from
the endometrium itself in saline infusion sonohystograms.
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Transvaginal
ultrasound of a postmenopausal woman with vaginal bleeding shows an
abnormally thickened endometrium. Endometrial biopsy revealed
atrophic endometrium.
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Endometrial Biopsy (EMB)
Gynecologists recommend that EMB be selected as an initial screening
test for the evaluation of post-menopausal bleeding. Alternatively, it
can be performed if the thickness of the endometrial stripe is >4 mm
in post-menopausal women and >16 mm in pre-menopausal women. In
addition, it should be performed if the endometrial stripe is <4 mm
is post-menopausal women and no cause for bleeding has been identified
by TVUS (or TVUS and saline infusion sonohysterography) because there
is a small risk (1.2%) of endometrial cancer in these women.
Saline Infusion Sonohysterography (SIS)
Saline infusion sonohysterography (SIS) is a very sensitive ultrasound
technique for detecting focal lesions because a small volume of saline
(<20 ml) is used to distend the uterine cavity in order to improve
visualization of the endometrial surface. SIS is a minimally invasive
alternative to hysteroscopy and is appropriate for further evaluation
of patients in whom a focal abnormality is suspected from TVUS as well
as patients in whom no cause for the bleeding has been identified after
biopsy and TVUS. In addition, SIS may be useful when a thickened
endometrium has been identified by TVUS because SIS can differentiate
between diffuse and focal thickening.
It should be pointed out that if the cause of bleeding cannot be
identified after SIS and EMB and if bleeding persists in a
post-menopausal patient, it is possible that the results from
ultrasound imaging and biopsy are false negatives. Therefore, the
patient should be referred for hysteroscopy and endometrial biopsy even
if her endometrial stripe is <4 mm. If the hysteroscopy-guided
biopsy is negative, the post-test probability of endometrial cancer is
0.5%.
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Sensitivity, Specificity, Positive and Negative Predictive Values
for Endometrial Cancer in Post-Menopausal Women
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Sensitivity |
Specificity |
PPV |
NPV |
| Transvaginal Ultrasound (TVU) |
67% |
56% |
7% |
97% |
| Endometrial Biopsy (EMB) (blind)* |
87% |
98.5% |
82% |
99.1% |
| Saline Infusion Sonohysterography (SIS) |
89% |
46% |
16% |
97% |
| Hysteroscopy and Biopsy |
86% |
99.2% |
100% |
99.5% |
| *Numbers include inadequate samples as negative |
| (Clark, TJ, Mann, CH et al. 2002; Critchley, HO, Warner, P et al. 2004; Clark, TJ, Voit, D et al. 2002) |
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Techniques for the Evaluation of Abnormal Vaginal Bleeding
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Advantages |
Disadvantages |
| Transvaginal Ultrasound (TVUS) |
Minimal patient discomfort post-test
probability of endometrial cancer is 1.2% if endometrium <4 mm |
If endometrium is thickened, need biopsy to confirm diagnosis |
Endometrial Biopsy
(EMB) |
Provides histological diagnosis of cancer |
May fail due to cervical stenosis
May fail to provide sufficient tissue for histology
11% False negative rate |
Saline Infusion Sonohysterography
(SIS) |
Surveys entire uterus
More sensitive than TVUS for detecting focal abnormalities of endometrium
May detect focal thickening of endometrium
More sensitive than hysteroscopy for detecting fibroids
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May cause cramping sensation
Treatment not possible
Positive findings require histological confirmation
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| Hysteroscopy |
Can biopsy and/or remove focal lesions
More sensitive than SIS for polyp detection |
Patients describe procedure as markedly unpleasant
View may be obscured
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Sonohysterography
reveals an endometrial polyp originating from the posterior wall of the
uterine fundus. Color doppler demonstrates the vascular stalk
(arrow). The polyp was resected hysteroscopically.
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Menorrhagia
SIS
is also appropriate for the evaluation of ovulating women with
menorrhagia. In these women, the examination should be performed within
the first week following the end of menstruation. At this point in the
menstrual cycle the endometrium is in the proliferative stage and is
relatively thin. Therefore, abnormalities are less likely to be
obscured. SIS is contraindicated if the patient is pregnant, has a
pelvic infection, or has unexplained pelvic tenderness.
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The Saline Infusion Sonohysterography Procedure
SIS
is generally a well-tolerated procedure although some women experience
mild to moderate cramping either during the insertion of the catheter
into the cervix or during the infusion of saline into the uterus.
Therefore, patients should be advised to take medication that they use
for normal menstrual cramps approximately one hour prior to the
examination. If the patient is allergic to latex products, it is
important to provide that information in advance of the examination
because it is necessary to prepare somewhat differently to accommodate
these patients.
SIS takes approximately one hour and
is performed by a radiologist experienced in this technique with the
assistance of an ultrasound technologist. First, a TVUS evaluation is
performed to image the uterus, endometrium, and ovaries. Then a
speculum is introduced into the vagina, the cervix is cleaned and a
small balloon catheter (3 mm) is inserted through the vagina into the
center of the cervix using sterile technique. Once in place, the
balloon is inflated to secure it in position and the speculum
withdrawn. The TVUS device is then reinserted and approximately 10-20
ml of sterile saline is gently infused into the uterus while real-time
images are observed. The entire uterine cavity is surveyed and
representative images acquired. This phase of the examination lasts
10-15 minutes. In some cases, women experience cramping during the
first 24 hours following SIS. If this occurs, they should continue to
take medication for menstrual cramps. |
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Scheduling
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Further Information
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Transvaginal
ultrasound may be performed at Mass General West Imaging in Waltham, in
Chelsea, and on the main MGH campus. However, saline infusion
sonohysterography is only performed on the main campus. Appointments at
all locations can be scheduled by calling 617-724-XRAY(9729). In
addition, transvaginal (pelvic) ultrasound but not sonohysterography
can be ordered through the web-based Radiology Order Entry system, http://mghroe
.
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For further questions on ultrasound, please contact Susanna Lee, M.D., Ph.D.,
Assistant Radiologist in the Abdominal Imaging and Intervention
Division, at 617-726-8396. In addition, further information on the
evaluation of abnormal vaginal bleeding can be found at the MGH Primary Care Office Insite website.
We would like to thank Linda Duska, M.D., gynecological oncologist and
Isaac Schiff, Chief of the Obstetrics and Gynecology Service at MGH for
their advice on the work-up of abnormal vaginal bleeding in the
preparation of this article.
This article provided useful information about the appropriate use of imaging studies:
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References
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Critchley, HO, Warner, P, Lee, AJ, Brechin, S, et al. (2004) Evaluation
of abnormal uterine bleeding: comparison of three outpatient procedures
within cohorts defined by age and menopausal status. Health Technol Assess 8: 1-139
Goldstein, RB, Bree, RL, Benson, CB, Benacerraf, BR, et al. (2001) Evaluation
of the woman with postmenopausal bleeding: Society of Radiologists in
Ultrasound-Sponsored Consensus Conference statement. J Ultrasound Med 20: 1025-1036
O'Neill, MJ. (2003) Sonohysterography. Radiol Clin North Am 41: 781-97
Shipp, TD. (2005) Does ultrasound have a role in the evaluation of postmenopausal bleeding and among postmenopausal women with endometrial cancer? Menopause 12: 8-11
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