AJR 2005; 184:1004-1009
© American Roentgen Ray Society
Characterization of Adnexal Masses with MRI
Ash Saini1,
Roberto Dina2,
G. Angus McIndoe3,
W. Patrick Soutter3,
Phillip Gishen1 and
Nandita M. deSouza1
1 Department of Imaging, Hammersmith Hospital, DuCane Rd., London W12 0HS,
England.
2 Department of Histopathology, Hammersmith Hospital, London W12 0HS,
England.
3 Department of Gynaecology, Hammersmith Hospital, London W12 0HS,
England.
Received May 5, 2004;
accepted after revision July 23, 2004.
Address correspondence to A. Saini.
Introduction
Thorough pretreatment evaluation is basic to the successful management of
suspected adnexal masses because the nature and timing of surgery can be
optimized if the nature of the lesion can be predicted. Although sonography is
indisputably the primary imaging approach
[1], MRI provides additional
information on the composition of soft-tissue masses using differences in MR
relaxation properties seen in various types of tissue
[2–4].
This information is invaluable in determining the character of soft-tissue
masses. In the pelvis, MRI has been shown to have a 91–93% overall
accuracy for differentiating benign from malignant adnexal tumors
[5] particularly when
gadolinium-enhanced techniques are used
[6]. This pictorial essay
reviews the key differentiating MRI features of adnexal masses by correlating
the MR appearances with the findings at histopathology.
Materials and Methods
MR images of 45 consecutive patients aged 28–87 years (mean ±
SD, 53.6 ± 16.0 years) with adnexal masses diagnosed at clinical
examination or on sonography were reviewed retrospectively. MRI was performed
on a 1.5-T scanner (Intera, Philips Medical Systems) using a four-channel
synergy pelvic phased-array coil. A reduction in bowel peristalsis was
achieved by intramuscular injection of 20 mg of hyoscine-N-butyl
bromide. Coronal and axial T1-weighted spin-echo images (TR/TE, 700/20), axial
and sagittal T2-weighted fast spin-echo images (TR/effective TE, 4,500/80),
and coronal STIR images (TR/TE, 3,000/30; inversion time, 165 msec) were
obtained with a 256 x 256 matrix, a 5- to 6-mm slice thickness, and a
30-cm field of view.
Results and Discussion
Solid lesions of a benign nature were characterized by fat, hemorrhage, or
fibrous components. Mature teratomas (dermoid cysts, n = 4) possessed
high fat content and contained derivatives of all three germ layers, with a
predominance of ectodermal components (Figs.
1A,
1B, and
1C). Fat was identified on STIR
images, although use of fat-saturated chemical shift techniques is preferable
to avoid confusion of fat with hemorrhagic lesions having the same T1
relaxation time as fat. T2-weighted images are invaluable for differentiation
in these cases. Hemorrhage was a predominant feature of endometriomas
(n = 7, Figs. 2A,
2B,
2C, and
2D) but also was seen in some
malignant tumors. Ovarian fibromas and cystadenofibromas share a similar
distinctive tissue component of dense fibrous tissue
[7]. They showed a distinctive
short T2 relaxation (Figs. 3A
and 3B), typically shorter than
that of skeletal muscle. Fibrothecomas are also of stromal origin with fibrous
component similar to fibromas. They had prominent myxoid degenerative change
and a less dense stroma, which increased the T2 relaxation time (Figs.
4A and
4B). Low signal intensity on
T2-weighted images also was seen within the fibrotic component of
cystadenofibromas (n = 3). Benign Brenner tumors (n = 2) are
histologically identifiable by islands of transitional epithelium in a dense
fibrotic stroma and so predictably had MR signal characteristics similar to
those of a fibroma (Figs. 5A
and 5B).
View larger version (159K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A. —40-year-old woman with mature teratoma. Coronal T1-weighted
spin-echo image (TR/TE, 700/20) shows bilateral partly solid, partly cystic,
multiloculated masses (arrows) with high signal intensity.
|
|
View larger version (158K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B. —40-year-old woman with mature teratoma. Coronal STIR image
(3,000/30; inversion time, 165 msec) shows nulling of high signal intensity,
indicating fat content (arrows). Dermoid cysts contain derivatives of
all three germ layers with predominance of ectodermal components.
|
|
View larger version (138K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1C. —40-year-old woman with mature teratoma. Photomicrograph of
histopathologic section obtained through mass shows locules of fat, together
with skin and appendages (hair follicles indicated by arrowheads). (H
and E, x80)
|
|
View larger version (151K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B. —46-year-old woman with endometrioma. Coronal STIR image (3,000/30;
inversion time, 165 msec) shows nulling of signal intensity in region
(arrow). T1 relaxation time of methemoglobin may be similar to that
of fat.
|
|
View larger version (167K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2C. —46-year-old woman with endometrioma. Sagittal T2-weighted fast
spin-echo image (TR/effective TE, 4,500/80) shows well-defined adnexal mass
with diffuse low signal intensity on periphery (arrow), corresponding
to hemorrhage.
|
|
View larger version (93K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2D. —46-year-old woman with endometrioma. Photomicrograph of
histopathologic section obtained through mass shows inner lining of
endometrial-type epithelium is lost and replaced by hemosiderin-laden
macrophages and hemorrhage (arrowhead). (H and E, x60)
|
|
View larger version (163K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A. —55-year-old woman with fibroma. Sagittal T2-weighted fast spin-echo
image (TR/effective TE, 4,500/80) shows well-circumscribed solid mass
(arrow) that is heterogeneous and low in signal intensity but
contains extremely low-signal-intensity components posteriorly.
|
|
View larger version (137K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B. —55-year-old woman with fibroma. Photomicrograph of histopathologic
section shows that low signal intensity represents fibroblastic cellular mass
in connective tissue stroma. (H and E, x400)
|
|
View larger version (132K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4A. —51-year-old woman with fibrothecoma. Sagittal T2-weighted fast
spin-echo image (TR/effective TE, 4,500/80) shows large, well-defined solid
mass with homogeneously intermediate signal intensity (solid arrow).
Degenerative cystic change is seen centrally with high-signal-intensity
component (open arrow). Loculated ascites (arrowhead) is
present and is common feature of these tumors.
|
|
View larger version (179K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4B. —51-year-old woman with fibrothecoma. Photomicrograph of histologic
section shows that mass was composed of elongated fibroblasts with fairly
abundant and vacuolated cytoplasm in loose stroma (compare with
Fig. 3B). (H and E,
x400)
|
|
View larger version (176K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5A. —68-year-old woman with Brenner tumor and cystadenoma. Coronal
T2-weighted fast spin-echo image (TR/effective TE, 4,500/80) shows bilateral
adnexal masses (arrows). Inferiorly, left-sided mass has solid
component (arrowhead) with very low signal intensity (relative to
that of skeletal muscle). Right-sided mass is cystic and multilocular. It
represents associated serous cystadenomas (compare with
Fig. 6A).
|
|
View larger version (144K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5B. —68-year-old woman with Brenner tumor and cystadenoma.
Photomicrograph of histologic section obtained through solid component shows
benign transitional epithelial clusters (Walthard's cell nests,
arrowheads) scattered in dense fibrous stroma, characteristic of
Brenner tumor. (H and E, x100)
|
|
View larger version (171K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6A. —52-year-old woman with serous cystadenoma. Sagittal T2-weighted fast
spin-echo image (TR/effective TE, 4,500/80) shows thin-walled unilocular cyst
with small nodule projecting from its anterior wall (arrow). Patient
had previously undergone hysterectomy.
|
|
Benign cystic lesions comprise serous or mucinous cystadenomas (n
= 5). Cystadenomas are the most common benign epithelial tumors and were
recognized as thin-walled unilocular or multilocular cysts (Figs.
6A and
6B). Borderline tumors
(n = 4) lacked stromal invasion and were mainly cystic with solid
components and papillary projections (Figs.
7A,
7B, and
7C). However, they often
lacked secondary features of malignancy such as ascites or omental cake.
View larger version (108K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6B. —52-year-old woman with serous cystadenoma. Photomicrograph of
histologic section reveals thin-walled simple cyst lined by bland serous
epithelium, confirming diagnosis. (H and E, x600)
|
|
View larger version (172K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 7A. —27-year-old woman with borderline serous tumor. Axial T2-weighted
fast spin-echo image (TR/effective TE, 4,500/80) shows well-defined
multicystic left adnexal mass (arrows) with numerous nodular
papillary projections (arrowhead) that extend into cystic
component.
|
|
View larger version (133K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 7B. —27-year-old woman with borderline serous tumor. Sagittal T2-weighted
image shows multicystic mass (solid arrows) with nodules
(arrowhead) in relation to residual normal-appearing left ovary
(open arrow).
|
|
View larger version (150K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 7C. —27-year-old woman with borderline serous tumor. Photomicrograph of
histologic section shows that projections are composed of fibrovascular cores
lined by stratified columnar cells, with no evidence of atypia. (H and E,
x400)
|
|
Malignant cystic lesions consist of epithelial ovarian tumors (n =
8) and were distinguished by their morphology (Figs.
8A and
8B) rather than by their
tissue signal intensity. The number and size of papillary projections and
presence of ascites have been described as important predictors of malignancy
[4]. Endometrioid
adenocarcinomas (n = 1) are cystic primary ovarian tumors that
resembled neoplasia found in the endometrium (Figs.
9A and
9B). They are often associated
with endometrial carcinoma of the uterus or endometriosis.
View larger version (187K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 8A. —63-year-old woman with serous cystadenocarcinoma. Sagittal
T2-weighted fast spin-echo image (TR/effective TE, 4,500/80) shows cystic mass
(solid arrows) with large papilliform solid component projecting into
it posteriorly (arrowhead) and breaching capsule (open
arrow).
|
|
View larger version (157K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 8B. —63-year-old woman with serous cystadenocarcinoma. Photomicrograph of
histologic section shows irregular papillary projections that extend into
cystic component (arrowhead). (H and E, x40)
|
|
View larger version (184K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 9A. —43-year-old woman with endometrioid adenocarcinoma. Sagittal
T2-weighted fast spin-echo image (TR/effective TE, 4,500/80) shows large
adnexal mass (solid arrows), predominantly cystic with solid
papillary components (arrowhead) within it. Uterus is bulky with mass
in endometrial cavity (open arrow).
|
|
View larger version (133K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 9B. —43-year-old woman with endometrioid adenocarcinoma. Photomicrograph
of histologic section shows malignant endometrial epithelium
(arrowheads) near surface of ovary with areas of necrosis. Uterine
lesion was entirely intramucosal and represented synchronous tumor. (H and E,
x100)
|
|
Malignant solid ovarian masses are less common than cystic tumors.
Granulosa cell tumors (n = 2) are slow-growing, predominantly solid
masses with variable amounts of cystic change
[8] and intratumoral hemorrhage
(Figs. 10A and
10B). An immature teratoma
(n = 1) did not contain any significant cystic component (Figs.
11A and
11B). Clear cell carcinomas
(n = 2) also were recognized as predominantly solid masses with more
modest cystic elements (Figs.
12A,
12B, and
12C).
View larger version (150K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 10A. —79-year-old woman with granulosa cell tumor. Sagittal T2-weighted
fast spin-echo image (TR/effective TE, 4,500/80) shows well-defined solid mass
(arrows) composed of large areas of homogeneous,
intermediate-signal-intensity tissue with scattered high-signal-intensity
cystic elements (arrowhead) seen centrally.
|
|
View larger version (150K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 10B. —79-year-old woman with granulosa cell tumor. Photomicrograph of
histopathologic section shows solid nest of granulosa cells with typical
convoluted and grooved nuclei. (H and E, x400)
|
|
View larger version (145K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 11A. —38-year-old woman with immature malignant teratoma. Axial
T2-weighted fast spin-echo image (TR/effective TE, 4,500/80) shows
well-defined solid mass in left adnexa (arrows) comprising areas of
mixed signal intensity. Normal ovary (arrowhead) is seen on right. Cx
= cervix.
|
|
View larger version (140K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 11B. —38-year-old woman with immature malignant teratoma. Photomicrograph
of histologic section shows that tumor consists of moderately differentiated
cells that are not terminally differentiated, indicating immature teratoma.
Tumor infiltration through muscular layer of adjacent colon
(arrowheads) is seen. (H and E, x400)
|
|
View larger version (175K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 12A. —50-year-old woman with clear cell carcinoma. Coronal T1-weighted
spin-echo image (TR/TE, 700/20) shows encapsulated adnexal mass with mucinous
cystic component (arrow) that has high signal intensity and large
solid element (arrowhead).
|
|
View larger version (159K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 12B. —50-year-old woman with clear cell carcinoma. Coronal STIR image
(3,000/30; inversion time, 165 msec) corresponding to A shows partial
nulling of mucinous cystic component of mass (arrow). Peripheral rim
of very low signal intensity (arrowhead) around solid component
represents hemorrhage.
|
|
View larger version (146K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 12C. —50-year-old woman with clear cell carcinoma. Photomicrograph of
histologic section reveals characteristic clear cells (vesicular nuclei and
prominent nucleoli with typical hobnailing). (H and E, x600)
|
|
Inflammatory masses (n = 3) also presented as complex adnexal
cysts. In these cases, the clinical history and examination were key in making
the diagnosis. A schematic for characterizing ovarian masses on the basis of
MRI features is given in Figure
13.
Conclusion
The ability to manipulate tissue contrast with MRI makes this technique an
invaluable tool in the assessment of complex adnexal masses, enabling
characterization of such masses and identification of features associated with
less common diseases.
References
- Funt SA, Hann LE. Detection and characterization of adnexal masses.
Radiol Clin North Am2002; 40:591
-608[Medline]
- Outwater EK, Dunton CJ. Imaging of the ovary and adnexa: clinical
issues and applications of MR imaging. Radiology1995; 194:1
-18[Abstract/Free Full Text]
- Huber S, Medl M, Baumann L, Czembirek H. Value of ultrasound and
magnetic resonance imaging in the preoperative evaluation of suspected ovarian
masses. Anticancer Res2002; 22:2501
-2507[Medline]
- Jeong YY, Outwater EK, Kang HK. Imaging evaluation of ovarian
masses. RadioGraphics2000; 20:1445
-1470[Abstract/Free Full Text]
- Sohaib SAA, Sahdev A, Van Trappen P, Jacobs IJ, Reznek RH.
Characterization of adnexal lesions on MR imaging. AJR2003; 180:1297
-1304[Abstract/Free Full Text]
- Hricak H, Chen M, Coakley FV, et al. Complex adnexal masses:
detection and characterization with MR imaging—multivariate analysis.
Radiology2000; 214:39
-46[Abstract/Free Full Text]
- Outwater EK, Siegelman ES, Talerman A, Dunton C. Ovarian fibromas
and cystadenofibromas: MRI features of the fibrous component. J
Magn Reson Imaging 1997;7:465
-471[Medline]
- Morikawa K, Hatabu H, Togashi K, Kataoka ML, Mori T, Konishi J.
Granulosa cell tumor of the ovary: MR findings. J Comput Assist
Tomogr 1997;21:1001
-1004[Medline]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Top
Introduction
Materials and Methods
