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

8.

427-442.

BG, Arger PH, Mintz ME. Leiomyomas in study. Radiology

Moss

AA, Mihara

K, Goldberg

H,

Glazer G. Review: computed tomography ofgynecologic diseases. AJR 1983; 141: 76-773. Kormano MJ, Goske MJ, Hamlin DJ, et al. tenuation

and

necologic

organs

diol 1981; Walsh JW.

contrast

enhancement

and tumors

1:307-311. Comparison

in CT. EurJ

Ra-

and

in the evaluation

pelvic masses. Clin Diagn Ultrasound 2:229-242. Elkin M. Genital tract calcification.

M, eds.

At-

of gy-

of ultrasound

tomography

er SR, Elkin

Plain

film

of 1979; In: Bak-

approach

to

abdominal calcifications. Philadelphia: Saunders, 1983; 123-135. Fleischer AC, Entman 55, Porrath SA, James AE. Sonographic evaluation of uterine mal-

formations and disorders. In: Saunders R, James AE, eds. The principles and practice of ultrasonography

cology. 9.

in obstetrics

3rd ed. Norwalk,

Crofts, 1985;

leiomyo-

it is important to remember primary modality for evaluleiomyomas. Ultrasonog-

is the first-line

7.

uterus. text-

164:375-380. BH,

computed

as en-

of the Novak’s

ed. Baltimore:

1981;

Coleman MC, Arenson RL, Toaff pregnancy: sonographic 1987;

uterine

10th

&Wilkins,

Lev-ToaffAS,

Gross

In: Rob-

3rd ed. Philadelphia:

Jones HW, Jones GS. Myoma In: Jones HW, Jones GS, eds.

‘A

radiCebal-

and Hilda

manuscript.

Robbins M

We thank

photographer,

mogr Hricak

1981;

gyne-

53 1-568.

Tada 5, Tsukioka

M, lshii

zunuma K. Computed tures of uterine myoma. 10.

and

Appleton-CenturyC, Tanaka tomographic J Comput

H, MifeaAssist To-

S(6):866-869.

H, Tscholakoff

D, Heinrichs

L, et al.

Uterine leiomyomas: correlation of MR, histopathologic findings, and symptoms. diology 1986; 158:385-391.

Casillas

et al

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Ra-

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1007