Diagnostic ultrasound ( PDFDrive )

546 PART II Abdominal and Pelvic Sonography
benign conditions (such as small polyps or ibroids) improves
the patient’s quality of life, morbidity, and survival; further
investigation is warranted. 137
Other studies have assessed the endometrium in asymptomatic
postmenopausal patients and concluded that an endometrium
of 8 mm or less can be considered normal. 35-39 Most of these
reports have included a mixed group of patients, with some
undergoing HRT and some not undergoing HRT. In a theoretical
cohort of postmenopausal women aged 50 years or older who
were not bleeding or receiving HRT, Smith-Bindman and colleagues
40 recommended that biopsy should be considered if the
endometrium measures greater than 11 mm, because the risk
of cancer is 6.7% (similar to that of a postmenopausal woman
with bleeding and endometrial thickness >5 mm). If the endometrium
measures 11 mm or less, biopsy is not needed because
the risk of cancer is extremely low. 40 Using this cutof provides
an acceptable trade-of between cancer detection and unnecessary
biopsies prompted by an incidental inding. In a recent study by
Jokubkiene and colleagues, it was conirmed that even if endometrial
focal lesions are present, there is likely no malignancy.
In that study of 510 asymptomatic postmenopausal women, 11%
had workup for endometrium of 5 mm or greater, and 34 (7%)
underwent hysteroscopic surgery or ultrasound surveillance.
here were 14.5 surgical procedures per premalignant lesion
(endometrial hyperplasia) diagnosed, and two women developed
severe complications from hysteroscopy. 141 At our institutions
we currently use the more sensitive but less speciic threshold
of 8 mm.
The Obstructed Uterus: Hydrometrocolpos
and Hematometrocolpos
Obstruction of the genital tract results in the accumulation of
secretions and blood in the uterus (metro) and/or vagina (colpos),
with the location depending on the amount and level of obstruction.
Before puberty, the accumulation of secretions in the vagina
and uterus is referred to as hydrometrocolpos. Ater menstruation,
hematometrocolpos results from the presence of retained
menstrual blood. he obstruction may be congenital and is usually
caused by an imperforate hymen. Other congenital causes include
a vaginal septum or vaginal atresia, or a noncommunicating
rudimentary uterine horn. 142 Hydrometra and hematometra
may also be acquired as a result of cervical stenosis from
endometrial or cervical tumors or from postradiation
ibrosis. 143,144
Causes of Endometrial Fluid
Congenital (imperforate hymen, vaginal septum, müllerian
anomaly)
Current menstruation
Pregnancy
Recent instrumentation or trauma
Prior radiation
Infection
Cervical stenosis
Obstructing lesion (endometrial or cervical cancer)
Sonographically, if the obstruction is at the vaginal level, there
is marked distention of the vagina and endometrial cavity with
luid. If seen before puberty, the accumulation of secretions is
oten anechoic. Ater menstruation, the presence of old blood
results in echogenic material in the luid (Fig. 15.16). here may
also be layering of the echogenic material, resulting in a luid-luid
level. Infrequently, blood may distend only the cervix, which
has been termed hematotrachelos. 145
Acquired hydrometra or hematometra usually shows a
distended, luid-illed endometrial cavity that may contain
echogenic material (Fig. 15.17). Superimposed infection (pyometra)
is diicult to distinguish from hydrometra on sonography,
and this diagnosis is usually made clinically in the presence of
hydrometra. 144
In postmenopausal women endometrial luid is of particular
concern given their increased risk of endometrial cancer owing
to age. However, even in this population the accumulation of
endometrial luid is more likely to be from a benign than from
a malignant cause. A small amount of luid within the endometrial
canal, detected on TVS, may be a normal inding in asymptomatic
b
A B C
FIG. 15.16 Hematocolpos. (A) Sagittal TAS in a young patient with imperforate hymen shows the vagina distended with moderately echogenic
material due to blood, compressing the bladder (b) anteriorly. (B) and (C) Fluid with internal echoes due to blood distends the vagina in a 26-year-old
patient with benign vaginal stenosis. (B) is a TAS image and (C) is a translabial ultrasound image.