CT Appearance of Uterine

CT Appearance
Uterine
Javier
Ronald
JorgeJ.
leiomyomas,
most
common
primary
commonly
pelvic
modality
these
tumors
for
CT
not
other
scans,
and
their
calcification,
by
secondary
changes,
infection,
necrosis,
CT
are
found
per-
first
with
be
their
findings
including
fatty
they
may
familiar
the
is the
examinations
leiomyomas
describe
of the
frequently
and
(CT)
become
authors
one
However,
symptoms,
Because
should
are
Ultrasonography
tomographic
indications.
The
as fibroids,
in women.
leiomyomas.
computed
radiologists
appearance.
myomas
found
accompanied
during
formed
known
tumors
for evaluating
are
incidentally
istic
l
Casillas,
MD
C. Joseph,
MD
Guerra,
Jr. MD
Uterine
on
of
noted
character-
of uterine
cystic
leio-
degeneration,
degeneration,
and
sarcomatous
degeneration.
INTRODUCTION
U
Uterine
leiomyoma,
countered
one
of the
as an incidental
for other
indications
most
common
finding
or in the
pelvic
on computed
workup
tumors
in women,
tomographic
of patients
with
(CT)
a pelvic
is often
scans
mass.
en-
obtained
It is there-
fore important
for radiologists
to become
familiar
with the spectrum
of their appearance.
In our 6-year experience,
which
encompasses
over 6,000
CT scans of the abdomen and pelvis,
we have encountered
97 cases of histologically
proved
uterine
leiomyomas.
The purpose
of this article
is to review
the CT findings
of these tumors, with emphasis
ed within
them.
GENERAL
U
significance
leiomyomas
fibrous
tissue
but
among
Clinically,
as a palpable
to compression
myomas
may
are commonly
from
smooth
terms:
degrees
of attenuation
detect-
black
and
called
muscle
other
fibroids,
cells
although
of the
dark-skinned
they
derive
( 1 ) . They
uterus
populations
not
occur
from
more
(2).
uterine
leiomyomas
are commonly
symptomless,
but they may occur
mass, accompanied
by bleeding
or pain, or with symptoms
secondary
of the mass on the bladder,
uterus,
or rectum.
Patients
with leiopresent
with hypermenorrhea,
although
the exact
mechanism
by
which
these tumors
produce
rhea is a common
indication
Index
of different
CHARACTERISTICS
Uterine
frequently
on the
Myoma.
854
.3 1 5
abnormal
bleeding
for surgery;
other
Uterine
#{149}
neoplasms.
854
.3 1 5
is still unknown.
indications
include
Uterine
neoplasms,
#{149}
CT,
Hypermenorrapid tumor
854
. 1 2 1 1
Uterus,
#{149}
CT,
854.1211
RadloGraphics
I
From
and
the
Received
1990;
the
10:999-1007
Department
Department
May
ofRadiology.
of Radiology,
7, 1990;
revision
University
Jackson
requestedjune
ofMiami
Memorial
6 and
School
Medical
ofMedicine,
Center,
receivedjuly
Miami.
20;
161
From
acceptedJul
1 NW
the
12th
1989
23.
Ave.
Miami,
RSNA
scientific
Address
reprint
FL 33136
assembly.
requests
toJ.C.
casNA,
1990
999
Figures
1-3.
possible
locations
(2)
(1)
Diagram
illustrates
of leiomyomas
Pathologic
specimen
the various
in the
uterus.
of an intramural
leio-
myoma
(arrow)
. UC = uterine cavity. (3) Pathologic
specimen
of multiple
subserosal
leiomyomas (55 ) . Arrow
indicates
uterine
cavity.
2.
3.
growth,
pelvic
fertility
myomas
(1 ,2)
during
quency
pain,
.
pressure,
The presence
pregnancy
of malpresentation,
and
impaired
of multiple
increases
the
retained
leiofre-
placen-
(3).
Leiomyomas
can markedly
enlarge,
a characteristic
that makes
differentiation
of these
tumors from other
pelvic
or abdominal
masses
sometimes
difficult.
Almost
any intrapelvic
abnormality
needs
to be differentiated
from
ta,
this
and
premature
uterine
contractions
condition.
mors
sizes.
2% of
mors
develop
The
are commonly
multiple
and of various
A solitary
leiomyoma
is found
in only
patients,
and the number
of these tumay reach
the hundreds.
They rarely
after menopause.
location
is variable
a characteristic
Those
in the
embedded
uterus
within
.
whorled
surface.
These
tu-
sal.
sal
Frequently,
masses
uterus
respectively.
RadioGrapbics
.
the myometrium
are referred
to as intramural
(Fig 2) When
they occur beneath
the covering peritoneum
of the uterine
corpus,
they
are called
subserosal
(Fig 3) Some
leiomyomas occur
in immediate
proximity
to the endometrium
and are designated
as submuco-
of the
U
1)
.
Leiomyomas
are usually
sharply
circumscribed,
unencapsulated
but discrete,
round,
firm, gray-white
masses;
cut specimens
have
1000
of leiomyomas
(Fig
U
Casillas
et al
the
subserosal
protrude
and
Such
from
into
and
the
the
endometrial
leiomyomas
Volume
outer
may
10
submucocontour
cavity,
become
Number
6
4b.
4c.
Figures
4, 5.
(4)
CT scans
of the normal
uterus
(U).
B = bladder.
(a) Unenhanced
CT
the uterus.
(b) In a CT scan of the pelvis
obtained
before
intravenous
administration
of
the attentuation
of the uterus
(cursor
1 ) is 77.7 HU. (c) On the contrast-enhanced
scan,
the uterus has increased
to 1 26.5 HU. Attenuation
of the soft tissues
(cursor
2 ) has not
changed
(55.3 HU in b vs 5 1 .9 HU in c). (5) CT scan of postpartum
uterus
(U) reveals
a! cavity
(F and arrow).
pedunculated.
The subserosal
type may protrude
into the broad
ligament
to create
an intraligamentous
leiomyoma
(1).
Hyaline
degeneration
is seen in almost
all
uterine
leiomyomas.
Other
secondary
changes
include
cystic
degeneration,
calcification,
infection,
necrosis,
fatty degeneration, or sarcomatous
transformation
(1,2).
U
NORMAL
UTERUS
The uterus
ANATOMY
is a pear-shaped
OF THE
organ,
scan demonstrates
contrast
material,
the attenuation
fluid
in endometri-
tention
and on normal
anatomic
(Fig 4) (4) . On CT scans obtained
venous
administration
of contrast
normal
other
myometrium
pelvic
tissue
window
pears
smooth
enhances
tissues
settings,
in contour
(Fig
variations
after
than
(5) . At soft-
4c)
normal
and
intra-
material,
more
4b,
the
of
significantly
uniform
uterus
ap-
in at-
tenuation,
although
central
uterine
fluid may
be seen in the absence
of disease
or in the
postpartum
uterus
(Fig 5).
usually
identified
on CT scans
in the midline
between
the bladder
and the rectum,
depending on the degree
of bladder
and rectal
dis-
November
1990
Casillas
et al
U
Ra4ioGrapbics
U
1001
5.
y.
Figures
(6) CT scan shows enlarged
uterus
(U),
with a lobulated
contour,
secondary
to a leiomyoma
(arrow)
. (7) CT scan of another patient demonstrates
a submucosal
leiomyoma
(arrow)
producing
deformity
of the endometrial
cavity. (8) CT scan obtained
due to hydrocolpos
secondary
to cervical
stenosis incidentally
reveals
a small calcified
uterine
leiomyoma
(arrow)
. (9) CT scan obtained
through
the
midabdomen
in a patient
with increasing
abdominal
girth demonstrates
a giant abdominopelvic
soft-tissue
mass
1002
U
RadioGrapbks
6-9.
(M
) and associated
U
Casillas
bilateral
et al
hydronephrosis
(H).
Volume
10
Number
6
10, 11.
Figures
cystic
(10)
areas. (11)
in pathologic
found
CT scan
demonstrates
CT scan shows
specimen.
U CT CHARACTERISTICS
LEIOMYOMAS
. Uterine
Deformity
Enlargement
An
uterus
enlarged
contour
have
(Fig
a uniformly
6)
with
solid
size
of
usually
with
be a prominent
feature,
uterine
enlargement
is difficult
with CT; therefore,
uterine
size
useful
criterion
for the differential
of leiomyoma
lobulations
uterine
be seen
to diagnose
alone
is not
diagnosis
.
of the uterus.
however,
such changes
may
body or in the lower
segment
Leiomyomas
can also
an intracavitary
mass obliterating
cavity
(Fig 7).
Leiomyomas
can be small
(Fig
occur
the
as
uterine
and
(1
,
The
tendency
are
,
noted
within
most
common
in cases
involve
broad
of hyaline
liquefication,
and
or an ovarian
cyst.
of
of leio-
areas
degenin ex-
practically
all of the original
involved
and converted
into
cavity,
a state that clinically
pregnancy
in
patients
Degeneration
seen
. It may
2 ,4)
were
3 5) . Calcifica-
,
be
is the
is toward
treme
cases
mor is thus
large
cystic
ulates
Cystic
changes
tumor.
(1
may
degeneration
eration
a
pills
changes
secondary
of the
or if the
control
Hyaline
myomas
minimal
(4) Alterations
in contour
or
are identified
more often
in the
fundus;
in the
masses.
all
.
may
large
Hyaline
tenuation
values
similar
to those
of uninvolved
uterus
(6)
Although
uterine
enlarge-
ment
birth
indicates
cells
diminish
in size after
can increase
suddenly
pregnancy
or cystic
Arrow
No malignant
usually
They
tion
.
at-
leiomyomas.
attenuation.
during
taking
CT findings
consistency,
of uterine
high
arche
and
menopause.
uterine
Leiomyomas
degeneration
atypically
Contour
a deformed
common
.
with
OF UTERINE
and
are the most
leiomyomas
hyalmne
a leiomyoma
tua
sim-
A leio-
myoma
with
necrosis
or degeneration
may be
seen on CT scans
as a low-attenuation
mass in
the uterus
(Fig 1 0) Occasionally,
areas
of
high attenuation
may be seen in atypical
.
leiomyomas
of the
uterus
(Fig
1 1).
8) or giant
(Fig 9) homogeneous
or inhomogeneous,
pelvic
or abdominopelvic
masses.
The
growth
of uterine
leiomyomas
is estrogen
,
pendent.
November
They
do not
1990
appear
until
after
demen-
Casillas
et al
U
RadioGrapbics
U
1003
-1
E.,i
Figures
12-14.
(12) CT scan demonstrates
enlarged uterus (U) and popcorn
calcifications
in a
leiomyoma
(arrow)
. Note bilateral
ovarian
cysts (C)
(13) CT scan of a 4 1 -year-old
patient
shows multiple
subserosal
and intramural
uterine
leiomyomas;
most of them are calcified
(arrows).
(14) CT scan reveals uterine
leiomyoma
with calcification
of solid mass type (arrow)
. Contour
deformity
of the uterus caused by other smaller
leiomyomas
(arrowheads)
is also evident.
.
.
Calcification
Calcification
is likely
to occur
in leiomyomas in the presence
of circulatory
disturbances,
such as those
commonly
found
in
older women
(2)
This dystrophic
calcificalion of solid
mass type usually
has a mottled
appearance
with no well-defined
curvilinear
rim (Fig 1 2) There
are, however,
calcificalions
in leiomyomas
that have a well-defined,
thin, high-attenuation
rim with relatively
littie internal
calcification,
and they can be
mottled,
whorled,
or streaked
(Fig 13).
Although
uterine
leiomyomas
are apt to be
multiple
in a given
patient,
calcification
may
14.
.
.
be present
in only
1 4) The soft-tissue
.
one of the tumors
(Fig
mass of an individual
leiomyoma
is frequently
ume of the calcification,
the fact that calcification
larger
than the volmerely
reflecting
may be limited
to
only
a part of the tumor
(7).
The presence
of calcification
in a uterine
mass is the most specific
sign of a leiomyoma
(6); however,
this finding
is reportedly
common
(7)
In one series,
calcifications
were found
in only 3%-5%
of leiomyomas
(8). In our experience,
10% ofuterine
un-
.
myomas
1004
U
Ra4ioGrapbics
U
Casillas
et al
contained
leio-
calcifications.
Volume
10
Number
6
16a.
16b.
15, 16.
(15a)
CT scan of an infected
and partially
within
the mass (arrow)
and peripheral
rim of calcification.
crotic area (arrow).
(16) CT scans of a 42-year-old
patient
ing and lower abdominal
pain. (a) Section
through
fundus
cavity (arrow) . (b) Section
through
lower pelvis shows the
cervix. At surgery an ulcerated,
submucosal
pedunculated
vix was found.
Figures
.
Infection
and
Infection
is more
leiomyomas
frequently
mass
(2)
the uterine
cending
leiomyoma
Necrosis
common
because
insufficient
.
in submucosal
their blood
to support
supply
is
the tumor
Their
exposed
position
adjacent
to
lumen
predisposes
them to as-
infection.
Occasionally,
is infected,
the central
when
core
the
may
necrosed
leiomyoma
shows pocket of gas
(15b)
Pathologic
specimen
shows a large newith a 1 -month
history
of heavy vaginal
bleedof the uterus
(U) shows
fluid
in endometrial
leiomyoma
(arrow)
protruding
through
the
uterine
leiomyoma
protruding
through
the cer-
torsion
of the pedicle,
farction,
degeneration,
tial infection
(Fig 1 6)
zarre
tumors
tures
blood
ment
or omentum,
supply,
and
to the uterus.
called
‘
adhere
‘parasitic”
.
with subsequent
necrosis,
and
Occasionally,
to surrounding
inpotensuch
bi-
struc-
develop
an auxiliary
lose their original
attachThey are sometimes
lelomyomas
(1).
be filled
with purulent
material
or gas
(Fig 15) (8).
Subserosal
and submucosal
leiomyomas
may become
pedunculated
and may undergo
November
1990
Caslllas
et al
U
RadioGraphics
U
1005
Figure 17.
CT scans of a leiomyosarcoma.
(a) Section
through
the upper
pelvis shows
the mass (M ) to the right of the rectosigmoid (R ) . (b) Sections through the lower
pelvis show the mass (M ) extending
into
the ischiorectal
fossa and displacing
the rectum to the left. B
bladder.
(c) Pathologic
specimen.
At surgery,
a large mass arising
from the lower segment
of the uterus
and
extending
into the ischiorectal
fossa was
found.
Leiomyosarcoma
was diagnosed
from
histologic
results.
to differentiate
myosarcoma
There
is no
a leiomyoma
on CT scans.
reliable
from
way
a leio-
C.
.
Sarcomatous
Degeneration
Leiomyosarcoma
tion of leiomyoma,
of cases. Malignancy
dom
diagnosed
preoperatively
it is impossible
mor
1006
U
RadioGrapbks
enlargement
suggest
Casillas
entity
Sudden
of a previously
should
U
this
leiomyoma.
growth
there
On CT scans,
to distinguish
or postmenopausal
uterine
mass
(Fig 17) (8).
because
symptoms.
a preexisting
accelerated
complica-
occurring
in less that 1%
in a leiomyoma
is sel-
are no characteristic
from
U
is an infrequent
this
et al
on the significance
tenuation
though
formity
these
static
of a
possibility
tu-
CONCLUSION
This report
illustrates
the
ances
of uterine
leiomyomas,
that
uterine
are the
masses,
ic CT sign
various
CT appearwith emphasis
of various
may
be seen
enlargement
most common
calcification
degrees
within
of at-
them.
Al-
and contour
CT findings
is the
most
deof
specif-
of a leiomyoma.
Noncalcified
leiomyomas
may be confused
with
other
pelvic
masses
on CT scans.
Distinguishing
between
such
leiomyomas
and a
malignant
uterine
neoplasm
is difficult.
Differentiation
of interstitial
leiomyoma
from
Volume
10
Number
6
riowledgments:
Vdepartment
! secretary,
for their
of this
bins
Bill Burke,
assistance
in the prepara-
SL.
Female
genital
SL, ed. Pathology.
Saunders,
1967;
tract.
book
1134-1135.
:
ofgynecology.
Williams
U
Figure 18.
CT scan shows
(M ) with cystic component
uterus
(U) . This mass
to that of a leiomyoma.
a large
ovarian
inseparable
mass
from the
has a CT appearance
5.
similar
6.
adenomyosis
is also difficult,
especially since these two lesions
are frequently
associated
(9), and is probably
beyond
the
current
resolution
of CT. Other
pathologic
conditions
involving
the uterus,
such
dometrial
or cervical
carcinoma,
may also
coexist
with uterine
leiomyomas.
In addilion,
extrauterine
masses,
in particular,
a variety of solid or cystic
ovarian
tumors,
may
be misdiagnosed
as subserosal
or pedunculated uterine
leiomyomas
(Fig 18).
Although
it is useful
to be familiar
with
the
different
appearance
mas on CT scans,
that CT is not the
ating or diagnosing
raphy
(US)
of uterine
imaging
study.
When
findings
from US are indeterminate,
magnetic
resonance
imaging
is the next
choice,
because
it offers
greater
sensitivity
(1 0) and specificity
than CT.
November
1990
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U
Ra-
RadioGrapbks
U
1007