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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5786_Библиотеки_им_академика_М_И_Перельмана.pdf
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Fig. 18.1 Endometrioma with ‘ground-glass’ appearance of the cyst contents.
Gynaecological pathology: tubes and ovaries
systems included morphological features and later on additional criteria such as
patient age or menopausal status were incorporated.
9,18,21
All scoring systems have a number of false-positive and false-negative test
results, depending on the variables included and the characteristics of the
population. As the statistical probability of correctly identifying a malignant
neoplasm on the basis of scoring systems increases with tumour complexity,
there is a tendency to underestimate early carcinoma with few atypical morphological features. Little is known about tumour biology and the dynamics
of tumour growth and this is true especially for the progression from benign
to malignant disease. Therefore the incorporation of continuous variables such
as wall thickness is problematic.
Accurate assessment of an ovarian tumour includes morphological features
and it is necessary to assign an individual therapeutic strategy. Extensive use of
morphological scoring systems, however, may be associated with a reduction of
the detection rate for early cancer.
BENIGN AND MALIGNANT NEOPLASMS OF THE OVARY
Advanced ultrasound technology has clearly improved the description of
ovarian lesions. However, correct interpretation of sonographic findings
remains a challenge due to the histological diversity of ovarian tumours.
Genuine neoplasms alone are divided into 35 subtypes according to the WHO
classification.
Description of the ultrasound characteristics of every tumour would exceed
the capacity of this book. We have therefore focused our interest on the most frequent histological entities and the most pronounced sonographic features.
19
317
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Dysfunctional ovarian cysts
Dysfunctional ovarian cysts originate from the follicle and become clinically
important when they are larger than 5 cm and do not show signs of regression
during an observation period of 2 months. According to our own results, 95% of
these cysts disappear spontaneously.
In contrast to inflammatory changes, endometriosis and malignant neoplasms,
dysfunctional cysts are generally not attached to the surrounding tissue and therefore acute torsion is more likely to occur.
Follicle cysts
Stimulated by follicle-stimulating hormone (FSH), the Graaffian follicles
develop up to a size of 20–25 mm. If they fail to ovulate, the transition to follicular cysts is fluent. Diameters of 3 cm and more are considered pathological
but the maximum diameter usually does not exceed 10 cm. Luteinized follicular
cysts, however, which may occur during pregnancy, could even reach a diameter
of 25 cm.21 Follicular cysts are eventually found even in postmenopausal women,
where they have been described up to 6 years after menopause.20 The typical
Ultrasound in obstetrics and gynaecology
sonographic finding is that of a unilocular cyst with a smooth wall, no papillary
projections and echo-lucent cyst fluid.
Corpus luteum cysts
Histological characteristics of corpus luteum cysts and differentiation from follicular cysts are signs that ovulation has taken place. The corpus luteum cyst
develops from the corpus luteum due to excessive central bleeding. The sonographic finding is that of a solitary cyst, which consists of hypoanechoic as well
as hyperechoic components. The ultrasound appearance depends very much on
the age of the cyst and the period of time between bleeding and first description.
Haemorrhage may have a ‘web-like’ or more homogeneous hypoechoic appearance like endometriomas, and retracted blood clots adherent to the inner surface
of the cyst may also be seen (Fig. 18.2). The average diameter of corpus luteum
cysts is 5 cm but they may range from 2.5 to 16 cm.1 Evaluation of the flow profile of blood vessels in the cyst wall by means of colour Doppler sonography is
of little help as neovascularization with low impedance to blood flow also occurs
and therefore discrimination from malignant neoplasms is hardly possible on the
basis of Doppler flow indices. However, differentiation of true solid tumour components from coagulated and retracted blood clots can easily be achieved by use
of colour Doppler.
318
Thecalutein cysts
Thecalutein cysts may develop following prolonged stimulation by luteinizing
hormone or hCG. Multiple, bilateral thecalutein cysts (hyperreactio luteinalis)
11
are found in 25% of women with gestational trophoblastic disease.
Similar pathological findings are seen due to overstimulation by gonadotropins in patients
receiving infertility treatment. Massively enlarged, multcystic ovaries can be seen
on ultrasound examination. The cysts have a smooth wall and the cyst content is
hypoanechoic.
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Fig. 18.2 Haemorrhagic cyst with web-like cyst contents.
Endometriosis
Endometriosis is defined by the occurrence of vital endometrial tissue outside the
uterine cavity. According to the localization of the ectopic endometrium, endometriosis genitalis interna (adenomyosis uteri) can be distinguished from endometriosis
genitalis externa and endometriosis extragenitalis. One of the typical locations of
endometriosis genitalis externa is the ovaries.
25
Endometriosis is a disease of women of reproductive age and the most typical
period of first diagnosis is between 20 and 40 years of age.
Transvaginal sonography shows one or more uni- or bilateral cysts of varying size (Fig.
18.3). The characteristic finding is that of homogeneous internal echoes of medium
density, the so-called ‘ground-glass’ appearance. Internal septa occur in about 10–30%
and the cystic wall is usually smooth.8 On macroscopic examination, the internal echoes
represent brownish viscous cyst contents and the endometriosis cysts are therefore also
called ‘chocolate cysts’. The patho-aetiology of these endometriomas is cyclic bleedings,
which contribute to their unique macroscopic and sonographic appearance.
Gynaecological pathology: tubes and ovaries
Epithelial ovarian tumours
Serous ovarian tumours
Amongst the epithelial ovarian neoplasms, the serous tumours contribute the
most frequent entity (Fig. 18.4). About 25% of all ovarian tumours belong to this
histological group and out of these, 50–70% are benign. In up to 20% both ovaries
are affected, especially in elderly patients.
The sonographic findings vary from unilocular smooth-walled cysts without
internal echoes to complex multilocular tumours with papillary vegetations. Even
internal echoes can be found in cases of bleeding or partly mucinous cyst contents. The probability of malignancy grows with increasing cyst size and increasing complexity
26,27
(Figs 18.5, 18.6).
319
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Ultrasound in obstetrics and gynaecology
Fig. 18.3 Unilocular cyst with fluid level of hypoechoic and isoechoic cyst contents of an
endometrioma.
320
Fig. 18.4 Serous cystadenoma.
Mucinous ovarian tumours
Mucinous neoplasms belong to the largest ovarian tumours; diameters of 20–30 cm
frequently occur. Out of the entire group of mucinous neoplasms, 10–15% are
tumours of low malignant potential and 5% are ovarian carcinomas. Unlike serous
ovarian tumours, mucinous lesions are frequently multilocular, and solid components can also be found (Fig. 18.7). In benign conditions the cyst walls and septa
Fig. 18.5 Cystadenocarcinoma.
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Gynaecological pathology: tubes and ovaries
Fig. 18.6 Unilocular cyst with a regular wall and without internal echoes. Histology revealed
a serous ovarian carcinoma stage Ia.
are thin and regular. The most characteristic finding is that of internal echoes due
to the high viscosity of the mucinous cyst fluid. Compartments without internal
echoes due to rather serous liquid, however, do not exclude a mucinous tumour.
Fibromas and fibrothecomas
Thecomas, fibromas, fibrothecomas and their malignant counterparts consist of
varying proportions of stromal and thecal elements. All appear as predominantly
solid tumours (Fig. 18.8). The classic sonographic finding is that of a hypoechoic
321
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Ultrasound in obstetrics and gynaecology
Fig. 18.7 Mucinous adenocarcinoma.
322
Fig. 18.8 Ovarian fibroma.
mass with posterior acoustic shadowing. In contrast to pedunculated and broad
ligament fibroids, a separate ipsilateral ovary is not seen. Colour Doppler assessment might be useful to identify the pedicle of fibroids and to describe a true
solid tumour, but further differentiation is academic, as virtually all solid masses
are genuine ovarian neoplasms and therefore immediate surgical excision should
be considered.
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Germ cell tumours
Germ cell tumours contribute to about 30% of all ovarian tumours in western countries but only to 3% of malignant neoplasms. Malignant forms appear almost exclusively
in the first two decades of life, and two-thirds of malignant ovarian tumours during
this period of time are germ cell tumours. Germ cell tumours are able to mimic normal embryogenesis and to develop complex and highly differentiated structures.
15
Teratomas make up 95% of all germ cell tumours and out of these, the mature
cystic teratomas or dermoid cysts are the clinically most relevant subgroup.
Dermoid cysts are the typical tumours of women in their reproductive age and
therefore it is not surprising that 10% are first described during pregnancy. The
sonographic feature is that of a clearly demarcated inhomogeneous tumour. Other
components without internal echoes, poor echoes and also pronounced density of
internal echoes can be observed. These components typically show sharp margins,
while the cystic echo-free portion is frequently crescent shaped. Occasionally teeth
are described as echo-dense foci with typical acoustic shadowing. Elements such
as hair and apocrine glands producing sebum contribute to a hyperechoic homogeneous ultrasound image. Although the appearance of dermoid cysts is so characteristic, almost one-quarter of these tumours are overlooked when using sonography.
One explanation is that the echo patterns within the cystic teratomas are similar
to those of the neighbouring bowel and only careful examination identifies the
smooth-walled tumours, especially when they lack hypoechoic cystic components.
Gynaecological pathology: tubes and ovaries
ADNEXAL TORSION
Adnexal torsion is a rare event but may cause severe abdominal pain and an acute
emergency situation with peritonitis, leucocytosis and anaemia. Acute torsion most
frequently develops on the basis of pre-existing cystic ovarian enlargement or a
sactosalpinx, and an increased incidence in early pregnancy has been reported.
3,7
On a patho-aetiological basis the sequels of acute torsion can be explained by
the imbalance of continuous arterial blood flow and diminished venous return
within the adnexal mass. This causes rapid ovarian swelling due to oedema and
haemorrhage. When arterial blood pressure is exceeded by the surrounding tissue, intraovarian blood flow ceases completely, resulting in acute ischaemia and
necrosis. Therefore, in order to prevent the loss of the whole organ, early diagnosis
and immediate surgical intervention are of crucial importance.
Sonographic features are the description of a cystic adnexal mass, and eventually
signs of haemorrhage or an oedema of the cyst wall can be documented. The introduction of colour Doppler has facilitated differential diagnosis. In the initial phase of acute
torsion, high-resistance, low-velocity arterial flow and absent venous return have been
described which are finally followed by complete absence of intraovarian blood flow.
TUBES
The most important finding is that the normal fallopian tubes generally are not
visible by means of transvaginal sonography unless they contrast with the surrounding tissue in some way or other.
323
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Fig. 18.9 Fallopian tube floating in peritoneal fluid.
Ultrasound in obstetrics and gynaecology
Visualization is achieved and the full length of the organ can sometimes be
•
documented if the tubes are floating in abundant peritoneal fluid.
The tube itself can be altered as a hydrosalpinx or sactosalpinx and
•
becomes visible due to distension with fluid (Fig. 18.9).
Finally the artificial use of echogenic contrast agents such as Echovist
•
enables the examination of tubal patency.
324
NON-INFECTIOUS DISEASES OF THE FALLOPIAN TUBES
Tubal pregnancy
The incidence of ectopic pregnancies has increased in the past few decades and due
to improved diagnostic facilities, early detection of this potentially life-threatening
disease has become more and more common. Ectopic pregnancies are mostly located
within the ampullary, isthmic or interstitial part of the tube, but abdominal and ovarian pregnancies have also been described. The clinical symptoms are variable and
sometimes confounding but classically, irregular vaginal bleeding, abdominal pain
and a positive hCG test are found. Immediate transvaginal sonography is of crucial
importance if a tubal pregnancy is suspected. Exclusion of an intrauterine pregnancy
is the first diagnostic hint, but in 10–20% of patients a so-called pseudogestational
sac is described. This confounding picture contributes to retained blood within the
uterine cavity, but its central location in contrast to the more eccentric chorionic
cavity enables differential diagnosis. The tubal pregnancy itself can be identified as
an annular hyperechoic structure with a hypoechoic centre. In cases of intact ectopic
pregnancy, the yolk sac and even a vital fetus might be identified.
According to our own results, free fluid in the cul-de-sac can be found in three
out of four tubal pregnancies. In cases of ruptured ectopics and severe haemorrhage,
however, the echogenicity of the fluid is increased due to the contribution of blood.
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In up to two-thirds of patients with a tubal pregnancy, a corpus luteum gravidi-
tate can be identified and misinterpretation must be avoided.
Fallopian tube carcinoma
Primary carcinomas of the fallopian tube are a relatively rare event, comprising
about 0.3% of all gynaecological cancers.28 They are almost exclusively adenocarcinomas. More frequently, the tubes are secondarily affected by neighbouring
organs such as the ovaries and the endometrium.
Ultrasound images may show a complex ‘sausage-like’ cystic tumour with thick
walls and solid components. On colour Doppler the tumour is highly vascular and
the flow profile suspicious for malignancy.
Hydrosalpinx
Hydrosalpinx characterized by a tube filled with serous fluid is a phenomenon
rather than a disease as such, due to various reasons. The hydrosalpinx or sactosalpinx occurs following occlusion of the fimbriae with consecutive storage of
the serous secretion of the tubal endothelium (Fig. 18.10). This occlusion might
be due to adhesions caused by endometriosis or infections of the lower pelvis or
even in the senium caused by atrophy. The sonographic appearance is that of a
longish cystic tumour, sometimes shaped like a corkscrew, with a smooth wall
but without internal echoes. The clinical significance depends on patient age and
complaints. As long as the hydrosalpinx can be clearly separated from the ovary,
follow-up is easily performed by means of sonography.
Gynaecological pathology: tubes and ovaries
Fig. 18.10 Inclusion of the fimbriated end of a fallopian tube within fluid-filled
pseudoperitoneal cysts.
325
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INFECTIOUS DISEASES OF THE FALLOPIAN TUBES
Pelvic inflammatory disease most frequently develops due to ascending infections
from the lower genital tract. However, a direct transmission from neighbouring foci
such as diverticulitis or an appendiceal abscess is also possible.
Acute and chronic consequences of the inflammatory process can be described.
Acute salpingitis eventually presents as an ultrasound picture of a swollen tortuous
tube with a distended lumen and increased blood flow in the tubal wall. Salpingitis
may lead to damage of the organ structure of varying degree. Peritubal adhesions as
well as obstruction of the fimbriated end and intratubal stenosis are typical complications. The obstruction of the distal parts of the fallopian tubes results in the storage of fluid in the tubal lumen and contributes to the macroscopic appearance of a
hydrosalpinx.
Persistent inflammatory disease in the damaged and obstructed tubes may cause
a pyosalpinx. On ultrasound, internal echoes in the distended and corkscrew-shaped
tube are highly indicative of the purulent exudate and thickened mucosal folds may
also be identified due to chronic inflammation (Fig. 18.11).
Ultrasound in obstetrics and gynaecology
The most severe complication of a genital infection is the development of a
tubo-ovarian abscess. Other adjacent organs such as the bowel or the omentum
can be agglutinated to the abscess. Ultrasound findings depend on the extension of disease. In the beginning, the thick-walled dilated tube may be identified
adherent to and almost embracing the ovary. Eventually fluid–debris levels can
be documented in the distended tube. The structure of the ovary itself becomes
more indistinct and differentiation of stroma and follicles may be impossible.
Later on, ultrasound images usually show a complex mass with hypoechoic inhomogeneous components. As the neighbouring structures of fallopian tube and ovary
are almost merged, they can hardly be distinguished on ultrasound.
326
Fig. 18.11 Fimbriated end of a pyosalpinx.