Differential
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
ARTHUR
Diagnosis C. FLEISCHER,’
of Pelvic A. EVERETTE
Masses
JAMES,
JR.,1
by Gray JAMES
B. MIULIS,2
An approach to the sonographic differential diagnosis of pelvic masses based on their size, location, internal consistency, and definition of borders is presented. Diagnostic schemes were derived from correlating the sonographic features with histomorphology in 170 surgIcally proven pelvic masses. Besides separating pelvic masses Into the conventional categories of cystic, complex, and solid, gray scale sonographic features of a pelvic mass can be used to subcategorize these masses into a more useful differential diagnoses. Although the features seen on a sonographic Image were specific In only two types of pelvic masses (pattern specificity greater than 85%), the sonographic information can be effec-
not be ascertained an indeterminate
tively
tient’s
utilized
for establishing
masses. Among the various homogenously cystic adnexal
pattern,
whereas
differential
diagnoses
clinic
cystic,
Using of
pelvic
and
less
specific
and
Received
October
Presented American
25, 1977; accepted after revision meeting of the American Ray Society President Award.
Roentgen
© 1978
American
131 :469-478, September Roentgen Ray Society
1978
in figure
were
and
12 asymptomatic
1 , the sonographic
categorized
and
Similarly,
hospital
cised
as
definition
of
to
qualities
size,
borders.
location,
The
schemes
were formulated from initial relative to the sonographic
if the
exact
location
of
a mass
could
by sonography, it was designated as having location. Clinical information from the pa-
chart
was
surgery,
mass
used
in the
formulation
of a differential
were
the histomorphologic
independently
features
evaluated
II and
III,
Denver,
Cob.
scanned with a fully distended verse, and oblique sonograms
interest
in
bladder,
1
and
cm intervals. other
pelvic
wall musculature
pelvic
lesion
to
be
available
North-
Longitudinal, transthrough the area of
such
as the
were identified
investigated.
units
EDC,
of the uterus,
landmarks
lateral
rescanned
2.25 MHz or a 3.5 Most patients were
bladder. were taken
The location
pelvic
were
; Picker
ford, Conn.) using a standard nonfocused MHz transducer with medium internal focus.
The
were retrospecIn a few cases,
masses which were excised relatively intact submersed in a water tank. Patients were scanned with commercially Sonograf
of the ex-
by a pathologist.
accuracy of categorical and specific diagnoses tively analyzed as being correct or incorrect.
Optimal
urinary
spine
in relation
machine
transducer angulations were determined factory scans with routine gain settings
and
to the
settings
and
empirically after were obtained.
satisThe
artifactual echoes created within the distended bladder were used as a reference for the evaluation of the echogenicity of other soft tissue structures. Compound scanning was utilized for visualization of soft tissue interfaces, whereas simple sector scans
were
erties.
The
brated
using
American
performed
to evaluate
equipment
used
the standard
Institute
acoustical
in this
study
attenuation was
100 mm test object
of Ultrasound
periodically
endorsed
propcali-
by the
in Medicine.
Findings
Of the 198 patients examined for confirmation and/or characterization of pelvic lesions, 170 scans were considered positive for a pelvic mass. Twenty-eight patients failed to demonstrate sonographic evidence of a pelvic lesion. Only six patients with negative sonograms were later surgically explored. Two of these patients were later found to have disease; one had a small solid ovarian adenocarcinoma and the other had a dermoid cyst.
examination pelvic mass. or surgery consisted of subsequent
April 12, 1978. Roentgen Ray Society,
Boston,
‘ Department of Radiology and Radiological Sciences, Vanderbilt University 5chool requests to A. C. Fleischer. 2 Department of Obstetrics and Gynecology, Vanderbilt University School of Medicine,
Am J Reentg.nol
listed
mass
cystic).
Following
mass
Methods
at the annual
disease
diagnosis.
in obstetrics.
A total of 198 patients underwent sonographic because of either a palpable or clinically suspected Of these, 170 underwent laparoscopy, laparatomy, and are included in this study. A control group patients with negative scans who were found on
pelvic
JULIAN2
,
nantly
Prior to the development of gray scale imaging, soft tissue masses could be characterized into only three major groups: cystic, complex, and solid depending on their attenuation properties [2]. Seldom were the findings on conventional bistable B-mode images specific for a particular type of pelvic mass. Since the advent of gray scale sonography, subtle interfaces within and around soft tissue masses are more apparent, making more specific differential diagnoses possible [3]. In this study, observations correlating the sonographic appearance of surgically proven pelvic masses with their morphologic characteristics are utilized in a scheme for differential diagnoses of these masses. Subjects
CONRAD
image [4, 5]. If a mass did not fall into a specific category such as cystic, complex, or solid, it was classified according to its predominant sonographic component (e.g. complex, predomi-
experienced widespread cliniin the last decade, its use in been much less extensive [1]. of pelvic masses has made diagnoses comparatively more than
from
consistency,
(Unirad
difficult
be free
AND
used for prospective categorization observations of tumor morphology
with internal septation was highly specific for a pseudomucinous cystadenoma. Several pelvic masses such as dermoid cysts demonstrated more than one sonographic appearance and, therefore, had to be considered in more than one diagnostic category.
Although sonography has cal application in obstetrics gynecologic disorders has The morphologic variety gynecologic sonographic
to
the criteria
each
internal
of pelvic
extrauterine
visits
Sonography
volunteers.
sonographic patterns observed, masses were the least specific
a predominantly
Scale
469
September
1977.
of Medicine,
Nashville,
A. C. Fleischer Nashville,
Tennessee
0361
is the
Tennessee
1977
37232.
recipient Address
of the reprint
37232.
-803X/78/0900-0469
$00.00
FLEISCHER
470 ADNEXAL I.
LOCATION AND SIZE
UNILATERAL -UTERINE __________ or BlLATERAL’PELvO.ABD0MlNAL* I NDETERM
NATE
HOMOGENOUS
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
CYSTIC
IIESEPTATED
/
INTERNAL
SOLID FOCI PREDOMINATELY
CYSTIC SOLID
CONSISTENCY
N
MILDLY SOLID..IIEE
WELL .
BORDERS
Can
be uterine
ECHOGENIC ECHOGENIC
DEFINED
MODERATELY POORLY
*
ECHOGENIC
MODERATELY MARKEDLY
WELL
DEFINED
DEFINED
or eslrouferins
Fig.
1 .-Sonographic
criteria.
Of the pelvic lesions studied, categorical diagnoses (according to the criteria listed in figure 1) were correct in 91% of the cases, and histologically specific diagnoses were correct in 71% of the cases. When categorical diagnoses were considered, the most numerous errors were in complex pelvic masses (15%); the fewest errors were in the group of cystic pelvic masses (4%). Specific diagnoses were correct in 73% of the cystic pelvic masses and 73% of the solid lesions. When compared to the group of gynecologic masses, sonographic evaluation of obstetrical pelvic masses had a higher rate of correct specific (91%) and categorical (98%) diagnoses. Schemes for differential diagnoses are presented in table 1 . By listing some masses in more than one category, the schemes take into account the specificity of each pattern relative to a certain type of pelvic mass. The specificity of a certain sonographic pattern for a particular type of pelvic mass is listed for each commonly encountered mass (more than 10 cases) in table 2. Six patients were found to have pelvic lesions which were not related to an obstetric or gynecologic problem. These cases included lymphomatous masses, mesenteric cyst, ectopic pelvic kidney, massively distended urinarybladder, and distended fluid-filled loops of small bowel which simulated the findings of a complex pelvic mass. Although it is well known that the size of the female reproductive organs vary according to age, parity, and endocrinologic factors, a range of normalcy for these structures was ascertained from the patients who were found to be clinically as well as sonographically free of pelvic disease. In general, uteri in these patients were 68 cm long and 3-4 cm wide. Uteri of multiparous patients were found to be 1-3 cm longer and wider than those in nulliparous patients, whereas infantile uteri averaged 35 cm in greatest length and tended to be tubular in shape. These estimations of normal uterine size agreed with the measurements cited in a major gynecology textbook [5] and with the data recently recorded by Sample et al. [6]. The uterine lumen became particularly echogenic during menses, and this phenomenon was
ET AL. used to help localize the uterus in relation to abnormal pelvic masses. Although quite variable in location, the ovaries of seven patients were identified on transverse tomograms as almond-shaped structures lateral to the uterine corpus. Normal ovaries were 1 .5-3 cm long and 0.5 cm wide. Consequently, adnexal masses greater than 3 cm were considered abnormal. Internal structures as small as ovarian follicles could occasionally be identified in enlarged ovaries. Similarly, physiologic enlargement of corpus luteum cysts during the first trimester of pregnancy can be recognized. Table 1 presents the sonographic features of the most commonly encountered pelvic masses in each sonographic category. The sonographic criteria used (fig. 1) were chosen on the basis of their diagnostic value and reproducibility [7]. These schemes are intended to serve as an outline for the sonographic evaluation of pelvic masses, even though masses which defy categorization according to this method may be occasionally encountered. In such cases masses should be categorized according to their predominant sonographic component (e.g., complex, predominantly cystic mass of indeterminate origin). In addition, it should be mentioned that masses not specific to an obstetric or gynecologic disorder can mimic the sonographic features of a frank pelvic mass. Pertinent clinical data such as age, presenting symptoms, and physical findings must always be taken into account when formulating a differential diagnosis using sonographic findings. Cystic
Masses
Although physiologic (functional) ovarian cysts were the most frequent type of cystic pelvic mass encountered in this study, several other masses had similar sonographic appearance (figs. 2A-2C). The majority of benign cystic masses appeared as well defined, spherical, completely sonolucent masses (figs. 2A and 2B). On the other hand, inflammatory, neoplastic, or cystic masses which had undergone torsion frequently demonstrated an unusually thick wall or low level internal echoes corresponding to areas of organized hemorrhage, proteinaceous material, or cellular debris within the cystic mass (see fig. 3A) [8, 9]. Adnexal,
Homogenous,
Well Defined
Borders
Physiologic ovarian cyst. Sonographic evaluation of these masses led to a correct specific diagnosis in 17 of the 18 cases encountered. Physiologic or functional ovarian cysts appeared as well defined, spherical, and completely sonolucent masses which averaged 3.5 cm in diameter. In five cases, the cystic portion of the ovary could be delineated in close proximity to the unaffected portion. Unclotted blood within the cyst could be identified by its layering effect or by change in its position when the patient was scanned in a different position. Organized clot could be recognized as an echogenic area within a cystic mass. An unusually thick wall was preoperatively recognized in one ovarian cyst that had
SONOGRAPHY
OF
PELVIC
TABLE Sonographic Location.
Internal
consistency
Differential
and Definition
Diagnosis
MASSES
471
1 of Gynecologic
Common
Pelvic
Masses
Uncommon
Rare
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
of Borders
Cystic Masses: Adnexal, homogenous, fined borders
well dePhysiologic
ovarian
Denmoid cyst Paraovanian cyst
cyst
Serous cystademona* Hydnosalpinx
Uymphocele Appendiceal abcesst Mesentenic cyst Peritoneal inclusion cyst U reterocelet
Endometnioma(s)t
Pelvoabdominal, septated moderately well defined
,
well to borders.
Pseudomucinous oma
Adnexal
or pelvoabdominal,
solid
foci, well to moderately
cystaden-
(cancinoma)
Dermoid
noma)* Loculated Loculated
lymphocele pelvic abscess
cyst
Tubo-ovanian Ectopic
Complex masses: Uterine predom abledefinition
(carci-
well de-
fined borders
,
Senous cystadenoma
inantly cystic
,
abscess*
pregnancy
vanlntnautenine
pregnancy
Invasive
Pyometnium
trophoblastic
tumor
Adenomyosis Uterine, predominantly solid to moderately well defined dens
,
well borUterine
leiomyoma*
Uterine
leiomyosarcoma
Endometnial
Extrauterine, moderately
predominantly cystic, well defi ned borders.
Fluid-filled
Tubo-ovanian abscess* Ectopic pregnancy
Ovarian cystadenoma noma) Extrauterine, predominantly solid, well to moderately well defined bonders
Degenerated tic
Solid masses: Uterine, moderately echogenic, well defined bonders
Uterine
solid
Indeterminate, variable ityanddefinition .
t
May present as pelvoabdominal Can be multiple bilateral. multiple.
ovaniest
cys-
Endometnial sarcoma
Ieiomyoma*
Solid ovarian tumon broma, teratoma, carcinoma)
Polycystic
tumor*
Uterine
Extrauterine, mildly to moderately echogenic, moderately well defined borders
loops of bowel
(canci-
or partially ovarian
carcinoma
(fi-
adeno-
carcinoma
on
Ieiomyosarcoma
Pedunculated Lymphoma*
leiomyoma
echogenicBowel
Uymphadenopathy Intraperitoneal fat
Aetropenitoneal Ectopic
pelvic
tumor kidney
mass.
* Usually § Usually
undergone torsion. The clinical regression of functional ovarian cysts after a trial of estrogen suppression was documented by serial sonographic examination in two patients. Serous cystadenoma. Although two of the large serous cyStadenomas contained a few internal septae, the smaller serous cystadenomas (less than 5 cm) were unilocular and exhibited a sonographic appearance which was indistinguishable from other cystic adnexal masses (fig. 2B). This condition became clinically suspect in five patients when a palpable cystic adnexal mass failed to regress after appropriate therapeutic trial of estrogen Suppression.
Hydrosalpinx. The fallopian tubes in the nondistended state cannot be routinely identified by present-day scanners. However, when they become distended with inflammatory material or serous secretions, these structunes became sonographically detectable as unilateral on bilateral fusiform sonolucent adnexal mass(es) (fig. 2C). Involvement of the ovary as part of the inflammatory mass (tubo-ovanian abscess) could not be reliably distinguished from an inflammatory process involving only the oviduct (hydrosalpinx). When distended tubes contained pus, low level echoes within these structures could be identified Unilateral hydrosalpinx was frequently found as a sequel to pelvic inflammation occurring wit intra.
FUEISCHER
472
ET AU.
TABLE
Pattern No
Mass
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
Ovarian
Common
C a ses
pseudomucinous
cystadenoma
. .
19
Ieiomyoma
Endometnioma(s)
Tubo-ovanian
abscess
Physiologic
Serous
ovarian
cyst
cystadenoma
Hydrosalpinx Note. .
Ratio
-Masses
uterine
of the
with
number
fewer
than
of times
contraceptive
10 cases
a particular
pelvoabdom-
20
18
90
28
25
89
12
nodular uterine enlargement Multiple cysts of various sizes
to moderately
echogenic,
predominantly
cystic,
with echogenic extrauterine
focus
ad-
14
10
71
21
13
61
18 35
9 14
50 40 33
17 19
Complex, nexal Complex Complex,
18
Cystic,
adnexal
52
17
16
Cystic,
adnexal
52
12
23
12
Cystic,
adnexal
52
10
20
mass
displaye
d a certai
or previous
n sonographic
tubal
appearance
Well to Moderately
divided
by the
total
numbe
surgery.
Well
The numerous thin septae found within pseudomucinous cystadenomas led to a specific diagnosis in all 18 cases encountered. The complexity or arrangement of the internal septations did not bean any relation to the malignant properties of the mass (figs. 2E and 2F). However, masses which contamed markedly irregular internal septations or were associated with ascites were more frequently malignant than benign (figs. 2G and 2H.)
Moderately
Pattern Specificity (%)
r of times
that
Complex
paR em
was
encountered.
Masses
In general, complex masses contained both fluid and solid components. Consequently, this group consisted mainly of solid masses which had undergone cystic internal degeneration or cystic masses which contained organized clot, cellular debris, thick inflammatory fluid, or sebaceum. Uterine,
Predominantly
Cystic,
Variable
Definition
Borders
Pseudomucinous
Adnexal
No. of Specific Masses with Pattern
not included.
devices
Septated,
cystic,
Mildly
Endometniomas exhibited a similar sonographic appearance to other cystic adnexal masses except that they were usually multiple and of varied size (0.5-15 cm) (fig. 2D). Low level echoes were observed within two endometniomas which were later found to contain clotted blood.
Defined
Total No. of Masses with Pattern
septated
Endometrioma(s).
Pelvoabdominal,
Features
27 18
Dermoid cyst Ectopic pregnancy
Sonographic
Predominantly
inal,
Uterine
2
Specificity
cystadenoma.
or Pelvoabdominal, Well
Defined
Solid
Foci,
Well
to
Borders
Dermoid cyst. Even though these masses demonstrated a wide spectrum of morphologic and sonographic features, the finding of a well defined focus of high level echoes within a predominantly cystic adnexal mass identified a dermoid cyst in approximately 50% of the cases (fig. 3E). As recently described by Guttman [9] and confirmed in our study, the hair ball and sebum commonly found within these masses is highly echogenic both in vivo and in vitro. This factor might have contributed to an error of recognition of a denmoid cyst secondary to an inability to adequately delineate the boundaries of this mass. In one patient, a calcified fibroma adjacent to a follicular cyst was mistaken for a dermoid cyst. Only one-half of the dermoid cysts demonstrated by sonognaphy revealed radiographically demonstrable calcification. Ectopic pregnancy. This will be discussed in the section on complex masses, extrauterine and predominantly cystic.
Intrauterine pregnancy. Occasionally, an intrauterine pregnancy will be verified by sonography in a patient in whom this condition is not suspected. An intrauterine gestational sac is depicted as a rounded cystic mass within the uterine fundus. A small echogenic embryonic pole can be detected as early as 4 weeks after implantation. Uterine,
Predominantly
Defined
Borders
Solid,
Well
to Moderately
Well
Degenerated solid uterine tumor. Although uterine leiomyoma (fibroids) were the most commonly encountered mass in this category, other intrauterine tumors such as adenomyosis and endometnial carcinoma exhibited a similar sonographic appearance. Of the 25 leiomyomas in this study, only six demonstrated a complex sonographic pattern. The majority of these Ieiomyoma were found to have undergone cystic internal degeneration or calcific degeneration which was depicted by focal areas of echogenicity and distal acoustical shadowing. Extrauterine, Predominantly Defined Borders
Cystic,
Moderately
Well
Tubo-ovarian abscess. Moderately distended oviducts may be distinguished from other cystic adnexal masses because they retain their fusiform shape. However, when the oviducts become markedly distended, they assume a more rounded shape. A complex sonographic texture can be recognized (fig. 3A) when inflammatory fluid or cellular debris is contained within a tubo-ovanian ab-
SONOGRAPHY
OF
PELVIC
MASSES
473
-k
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
.-4
I,
U
.
A
_
j
..
Fig. 2.-Cystic pelvic masses. A, Transverse sonogram 4 cm above symphysis pubis showing homogenously cystic left adnexal mass (large arrow). Unaffected ovary (small arrow) and uterus (U) can also be identified. This physiologic ovarian cyst regressed after 1 month trial of estrogen suppression. B, Transverse sonogram 5 cm above symphysis pubis showing homogenously cystic right adnexal mass (arrow). This serous cystadenoma failed to regress after appropriate trial of estrogen suppression. Sonographic appearance is indistinguishable from ovarian cyst in A. c, Transverse sonogram 4 cm above symphysis pubis showing fusiform homogenously cystic, right adnexal mass (arrow). At surgery, massively distended oviduct 0, Transverse
or hydrosalpinx was found. sonogram 4 cm above symphysis
pubis
demonstrating
multiple
cystic
masses
of various
sizes
(arrows)
representing
multiple
endometriomas. Organized blood within these masses may emanate low level internal echoes. E and F, Longitudinal sonogram in midline (E) and transverse sonogram at level of umbilicus (F) showing large predominantly cystic pelvoabdominal mass with multiple internal septations (arrow). This appearance is highly specific for pseudomucinous cystadenoma. G and H, Transverse sonogram 4 cm above symphysis pubis (G) and 6 cm below xyphoid (H) depicting predominantly cystic pelvic mass (arrows) which
is associated
with
ascites
(asterisks).
At surgery,
patient
had malignant
scess. linear
pseudomucinous
The inflammatory fluid may layer out, causing a acoustical interface within the predominantly cystic mass (fig. 3A). Distended fluid-filled loops of small bowel may also simulate these findings even though, on occasion, a characteristic echo complex emanating from the valvuale conneventes or mucosa may be recognized
tients
[10].
with
Ectopic pregnancy. Because gestational sacs formed outside the uterus do not usually exhibit the easily recognizable oval ring seen with intrauterine pregnancies, this condition can be easily confused for other complex-appearing adnexal masses [11]. However, pa-
with
cystadenocarcinoma.
an ectopic
ascites,
pregnancy
and peritoneal
usually
implants.
present
with
the
fairly consistent clinical ble adnexal mass, and,
findings of amenorrhea, palpaif rupture and intrapenitoneal
bleeding abdominal
acute
The
fact
that
ectopic
makes
tions ning
has occurred, signs. approximately
gestations
differentiation
clinically techniques
differentiated
onstration
blood
loss
and/or
three-fourths
will of this
experience condition
of
vaginal from
from
this
condition
gestational
by sonographic
sac
patients
bleeding
missed
difficult [12]. However, if meticulous are followed, missed abortions
of a deformed
acute
which
abor-
scancan be dem-
is intna-
FLEISCHER
474
ET AL.
----------v-
rII
,..-
a.,
-
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
J
I.
A
B a
.
“p-
.-
I,’
/
.,..
Fig.
3.-Complex
A, Transverse abscess
contained
B, Transverse found
to have
perpendicularly
pelvic masses. sonogram 2 cm above symphysis pubis showing 20 ml of pus which layered in supine position.
sonogram small
to central
C and 0, Longitudinal
(arrows). uterus.
blood
u
uterus.
-
Ruptured
which
ectopic
was found
6 cm above symphysis
bowel
obstruction
secondary
pubis showing to adhesions
complex
left
complex with
adnexal
mass
with
linear
internal
left pelvic mass with linear echo interface markedly
distended
fluid-filled
jejunum.
emanated from valvulae conniventes (arrow). (C) and transverse scan 4 cm above symphysis pubis (D) showing of ectopic pregnancy was raised by sonogram even though by palpation
interface probably scan at midline
Possibility tubal
in region
pregnancy
of ruptured
was
subsequently
right
found.
interface
Echoes
seen
on
transverse
scan
centrally. Pattern
complex, mass was
probably
(arrow).
emanated
tubo-ovarian
At surgery,
of
poorly thought
This
linear
patient
echoes
was
oriented
defined retrouterine mass to represent retroflexed
from
small
fetus
and
clotted
oviduct.
E, Longitudinal scan at midline showing complex, predominantly solid mass anterior to uterus (U). Focus of high level echoes within mass (arrow) corresponded to areas of radiologically demonstrable calcifications. Dermoid cyst contained tooth and large amount of sebaceum. F, Longitudinal scan at midline showing cystic pelvic mass anterior to uterus (arrows). Mass also was dermoid cyst but contained predominantly cerebrospinal fluid. Variety of sonographic appearances of dermoid cysts is demonstrated in E and F.
uterine. Although an extrauterine complex adnexal mass can be identified in the majority of cases of ectopic gestation (12 of 14 cases), occasionally only secondary signs of an ectopic gestation such as free intrapenitoneal fluid or an enlarged uterus with an echogenic lumen can be found (figs. 3C and 3D). A negative sonogram, therefore, should not exclude further clinical evaluation of a patient suspected of having an ectopic gestation.
Extrauterine, Well Defined
Predominantly Borders
Solid,
Well
to
Moderately
Degenerated or partially cystic solid ovarian tumors. As stated previously, denmoid cysts demonstrate a wide variety of sonographic appearances. About one-third of dermoid cysts exhibited a complex, predominantly solid sonographic appearance which contained at least one focus of high level echoes (fig. 3E). Other solid ovarian masses such as dysgerminomas or sex cord tumors which characteristically contain areas of cystic internal degeneration also consistently demonstrated a complex sonognaphic appearance.
Solid
Masses
The majority of solid masses have an echogenic texture which can be enhanced by increased sensitivity settings. As observed in the in vitro and in vivo images of lymphomatous masses (fig. 4D) and a nondegenerated uterine leiomyoma (fig. 4A), the echogenicity of a mass seems to be related to the amount, arrangement, and elasticity of its stromal components [12-14]. Uterine,
Moderately
Uterine graphic
leiomyoma. appearance
Echogenic,
Well
As stated of these
Defined
Borders
previously,
masses
was
the related
sonoto the
amount and type of internal degeneration that had taken place within the mass. Their relatively homogenous histologic texture is mildly to moderately echogenic at routine gain settings (fig. 4A). These masses usually produce nodular enlargement of the uterine outline. The sonographic
localization
pregnancy
is of clinical
myomas
may
prohibit
vaginal
cause
delivery
of Ieiomyomas
importance significant
altogether
associated
since uterine
(fig.
with
cervical dystocia
4B).
Ieioand
Interest-
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
SONOGRAPHY
OF
leiomyomas found with pregnancy tend to become more sonolucent as the pregnancy progresses, perhaps because of increased blood flow to the uterus (fig. 4B). Predictions concerning the benign or malignant properties of a leiomyoma were not reliable, since patients with endometnial carcinoma and sarcoma exhibited sonographic findings similar to those with benign Ieiomyomata.
PELVIC
MASSES
Discussion
ingly,
Extrauterine,
Moderately
Mildly
Well
to Moderately
Defined
Echo
genic,
Borders
Solid ovarian tumor. In general, solid ovarian tumors are less common than cystic ones. Small solid ovarian tumors can sometimes be difficult to distinguish from surrounding soft tissue because of their acoustic similarity. Benign solid ovarian tumors included ovarian fibromas (Brenner tumor), whereas adenocarcinoma and metastatic ovarian tumors (including Knukenbeng tumor) represented the malignant varieties (fig. 4D).
Our experience concerning the sonographic evaluation of gynecologic pelvic masses agrees closely with that recently reported by Lawson and Albarelli [15]. In the majority of cases, sonography affords an accurate assessment of the presence, size, location, and internal consistency of a pelvic mass. These data, in turn, can be used to formulate the most likely diagnostic possibilities. Since only six patients with negative scans underwent surgery, the exact number of true and false negative cases could not be determined. A few pelvic masses were found to have a variety of morphologic consistencies, which explains their varied sonographic appearances. Most notable among these masses was the dermoid cyst which varied from completely cystic to a complex, predominantly solid pelvoabdominal mass. As a consequence of their lack of consistent features, such masses are considered in more than one sonographic category (table 1). Occasionally, certam
Indeterminate
Location
,
Variable
Echogenicity
and
Definition Bowel. Occasionally, large bowel filled with fecal material or large solid tumors of the gastrointestinal tract can be confused for a solid pelvic mass. These “pseudo” masses may be recognized by their peristaltic motion as detected by real-time scanning or by their cystic appearance after a water enema has been administered. In general, the nature of these masses is best documented by an abdominal radiograph or by contrast gastrointestinal series.
475
sonographic
features
were
specific
for a particular
type of pelvic mass (table 2). These include the thin internal septations seen within pseudomucinous cystadenomas and the echogenic appearance and nodular configuration of leiomyomatous uteri. The majority of errors in specification of mass lesions occurred in the complex and solid pelvic mass categories. These errors might be attributed to suboptimal scanning techniques (e.g. improper transducer angulation or gain settings) combined with the intrinsic acoustical similarity of some solid soft tissue masses compared to surrounding soft tissue structures. ,
FLEISCHER
Downloaded from www.ajronline.org by 129.64.99.141 on 09/25/14 from IP address 129.64.99.141. Copyright ARRS. For personal use only; all rights reserved
476
Although the exact role of sonography is yet to be established, its noninvasive and atraumatic qualities make it particularly desirable for the initial evaluation of a child orwoman with a pelvic mass [16-18]. Sonography permits determination of the size, location, and internal consistency of abnormal soft tissue masses and provides an objective means for serial examination of the size of a mass during or after therapy. The ability to make a specific diagnosis by sonography is particularly useful when a pelvic mass is found concomitant with an intrauterine pregnancy or when nonsurgical management is considered. Lymphadenopathy or ascites associated with a pelvic neoplasm can also be detected by sonography and have significant clinical importance [19]. The schemes presented here have proved effective in formulating a differential diagnosis of a pelvic mass based on its clinical presentation and sonographic features.
We express our appreciation to Ann Lindsey for obtaining many of the images, Sally Oliver for typing the manuscnipt, and John Bobbitt for photographic support. REFERENCES .
Am
W: Sonognaphy
13:457-466,
in gynecology.
Radiol
Clin North
1975
2. Morley P, Bannett W: The use of ultrasound in the diagnosis of pelvic masses. Br J Radiol 43 :602-616, 1970 3. Kossoff G, Gannett W, Aadovanovich G: Gray-scale echognaphy in ob-gyn Aust Radiol 18 :63-1 1 1 1974 4. Fleischen A, Brown M, Wilds P: Gray-scale sonography in the morphological diagnosis of selected gynecologic tumons, in Ultrasound in Medicine, edited by White D, New York, Plenum, vol 2, 1976, pp 213-218 5. Novak E, Woodruff A: Gynecological and Obstetrical Pathology. Philadelphia, Saunders, 1974 .
6. Sample W, Lippe B, Gyepes M: Gray-scale ultrasonognaphy of the normal female pelvis. Radiology 125 :477-483, 1977 7. Kossoff G, Garrett W, Carpenter A, Jellins J: Principles and classification of soft tissue by gray-scale echognaphy. Ultrasound Med Biol 2 : 89-1 05, 1976 8. Cunningham J, Wonton W, Cunningham M: Gray-scale echogenicity of soluble protein and protein aggnegates (an in vitro study). JCU 4 :417-420, 1976 9. Guttman P: In search of the elusive benign cystic tenatoma: “tip 10.
of iceberg”
Dowling
,
sign.JCU
A, Fleischen
5:403-406,
A, James
1977
AE Jn: Sonographic
pattenns
of distended fluid-filled bowel. In preparation 1 1 Conrad M Johnson J James AE Jn: Sonography in ectopic pregnancy, in Ultrasonography in Obstetrics and Gynecology, edited by Sanders AC, James AE Jr, New York, Apple.
,
,
ton-Centuny-Crofts,
12. Hellman
1977,
U, Pritchard
13. von Minsky pelvic
New York,
Obstetrics.
1971
U: Experimental
echoes
from
p 113
J: Williams’s
Appleton-Century-Cnofts, tissue
ACKNOWLEDGMENTS
1 Cochnane
ET AU.
with
investigation
particular
neoplasms
attention
(abstn.)
into the origin to
Obstet
signals
Gynecol
of
arising
31 :586,
1968
14. Fields tion
5, Dunn
of tissue
with
F: Correlation biological
of the echographic composition
and
visualizaphysiological
state. J Acoust Soc Am 54 :809-812, 1973 15. Lawson T, Albanelli J: Diagnosis of gynecologic pelvic mass by gray-scale ultrasonognaphy: an analysis of accuracy and specificity. Am J Roentgenol 128 : 1003-1006, 1977 16. Carter B, Kahn A, Wolpent 5, Hammenschlag 5, Schwartz A, Scott A: Unusual pelvic masses: a comparison of CT and ultnasonognaphy. Radiology 121 : 383-390, 1976 17. HaIler J, Schneiden E, Kassnen G, Staiano 5: Ultrasonognaphy in pediatric gynecology and obstetrics. Am J Roentgenol 128:423-429, 1977 18. Taylor K: Current status of toxicity investigations. JCU 2:149-154,
1974
19. Rochester D, Bowie staging lymphomas.
J, Hunzman Radiology
C, Hester 124 :483-487,
E: Ultrasound 1977
in