DOI:10.2214/AJR.04.0997
AJR 2006; 186:1039-1045
© American Roentgen Ray Society
CT and MRI of Adnexal Masses in Patients with Primary Nonovarian Malignancy
Wei-Chao Chang1,
Maya D. Meux1,
Benjamin M. Yeh1,
Aliya Qayyum1,
Bonnie N. Joe1,
Lee-may Chen2 and
Fergus V. Coakley1
1 Department of Radiology, University of California San Francisco, Box 0628,
M-372 505 Parnassus Ave., San Francisco, CA 94143-0628.
2 Department of Gynecologic Oncology, University of California San Francisco,
San Francisco, California 94143-0628.
Received June 24, 2004;
accepted after revision March 8, 2005.
Address correspondence to F. V. Coakley
(Fergus.Coakley{at}radiology.ucsf.edu).
Abstract
OBJECTIVE. The purpose of this pictorial essay is to review the
differential considerations when an adnexal mass is detected on CT or MRI in a
patient with a primary nonovarian malignancy.
CONCLUSION. Such adnexal masses may be metastases to the ovaries,
primary ovarian malignancy, or incidental benign disorders. Solid masses are
more likely metastases, but metastases can be predominantly cystic and primary
ovarian cancers can be solid. MRI may help characterize incidental benign
entities such as endometriosis, fibroma, and peritoneal inclusion cysts.
Keywords: abdominal imaging • CT • genitourinary tract imaging • MRI • oncologic imaging
Introduction
CT and MRI of the abdomen and pelvis serve a crucial role in the diagnosis
and follow-up of many nonovarian malignancies. Adnexal masses in these
patients are an imaging dilemma because they may represent metastases to the
ovaries, primary ovarian malignancy, or incidental benign pathology. Primary
ovarian malignancy can be associated with nonovarian cancer, the prototypical
example of the latter being the increased frequency of ovarian cancer in
patients with breast cancer due to mutations in the BRCA (breast cancer) gene.
Incidental benign masses are also an important consideration because
5–10% of women in the United States undergo surgery for a suspected
adnexal mass during their lifetime
[1]. Many of these benign
masses can be expected to occur with similar frequency in both oncologic and
nononcologic patients. For these reasons, this pictorial essay aims to provide
a practical review of adnexal masses seen on CT and MRI in patients with
nonovarian malignancy and highlights imaging features that assist in
differential diagnosis.
Metastases to the Ovary
Tumors may metastasize to the ovaries via direct extension or peritoneal
spread. Metastases to the ovaries account for 10% of ovarian cancers. The term
Krukenberg tumor is sometimes used as a synonym for metastases to the ovary,
but strictly this term refers to a metastasis consisting of mucin-filled
signetring cells in a cellular stroma, usually from a carcinoma of the gastric
antrum. By this definition, only 30% to 40% of ovarian metastases are
Krukenberg tumors [2]. In
practice, up to 65% of ovarian metastases are from primary colon cancers
[3]. Other common primary sites
include the stomach, breast, lung, and pancreas. Ovarian masses in patients
with breast cancer merit particular mention because of the prevalence of
breast cancer. In a series of 121 patients with breast cancer who underwent
resection of adnexal masses, 61 patients had benign and 60 had malignant
adnexal disease [4]. Of the
malignant cases, 44 were primary ovarian cancer and 16 were metastatic breast
cancer.
Metastases to the ovary are typically bilateral, solid, and strongly
enhancing (Fig. 1). However,
cystic and necrotic areas are common, such that the tumors may be
predominantly cystic and resemble primary ovarian cancer
(Fig. 2). The overlap of
radiologic appearances between primary ovarian cancer and metastases to the
ovaries is substantial, and confident imaging distinction between the two may
be impossible [5]. The clinical
or imaging context may be helpful because in patients with metastases to the
ovaries, the primary tumor is often clinically overt and associated with
findings of widespread metastatic disease
[6]. Ovarian lymphoma is
characterized by large bilateral minimally enhancing solid ovarian masses with
homogeneously low T1 and mildly high T2 signal intensity and without necrosis,
hemorrhage, or calcification
[7]. Systemic lymphomatous
deposits may suggest the diagnosis (Figs.
3A and
3B). Leukemic involvement of
the ovaries is rare, but the ovaries may be a site of relapse (Figs.
4A and
4B). Melanoma may metastasize
to the ovary (Fig. 5) or rarely
arise in situ because of malignant transformation of melanocytes in a mature
cystic teratoma. Pancreatic adenocarcinoma may metastasize to the ovaries, and
an appearance mimicking primary mucinous ovarian tumor has been reported
[8]
(Fig. 6).
View larger version (116K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A —37-year-old woman. Widespread adenopathy suggests diagnosis
of lymphoma; otherwise, masses shown in A are relatively nonspecific.
Axial CT image with bilateral solid lymphomatous masses (arrows) in
ovaries.
|
|
View larger version (84K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B —37-year-old woman. Widespread adenopathy suggests diagnosis
of lymphoma; otherwise, masses shown in A are relatively nonspecific.
Coronal image from PET scan shows extensive increased nodal activity.
|
|
Occasionally patients present with widespread peritoneal malignancy,
omental cake, and an elevated cancer antigen-125 (like ovarian cancer), but
the ovaries appear normal or only slightly enlarged (unlike ovarian cancer)
[9]
(Fig. 7). This radiologic
appearance is suggestive of primary (papillary serous) peritoneal carcinoma, a
malignancy that is believed to arise directly from the extraovarian peritoneal
epithelium. Recognition of the typical constellation of findings not only
suggests the diagnosis but may prevent inappropriate investigation for an
extraabdominal primary tumor. Distinction of primary peritoneal from ovarian
papillary serous carcinoma is otherwise largely academic, since both are
treated with cytoreductive surgery and platin-based chemotherapy and have a
similar prognosis [9].
View larger version (126K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 7 —67-year-old woman with abdominal discomfort and elevated cancer
antigen-125 levels. Axial CT image shows omental cake (asterisk) and
normal-sized ovaries (arrows) adjacent to uterine fundus (UT).
Findings suggest primary peritoneal cancer; diagnosis of poorly differentiated
papillary serous carcinoma of peritoneum with no involvement of ovaries
confirmed at surgery.
|
|
Primary Ovarian Cancer
View larger version (133K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 9 —47-year-old woman with breast cancer. Axial CT image shows right
adnexal mass with characteristic features of mature cystic teratoma (dermoid
cyst), including tooth-like calcification (vertical arrow), adipose
tissue (asterisk), and Rokitansky nodule (horizontal
arrow).
|
|
Most primary ovarian cancers appear as cystic masses that are frequently
large and bilateral (Fig. 8).
Features that suggest malignancy in an ovarian cyst are thick walls (> 3
mm) or septa, nodules, vegetations, or papillary projections. Malignancy in a
solid ovarian lesion is suggested by necrosis. Although these features are
usually detectable by contrast-enhanced CT, gadolinium-enhanced MRI is
slightly superior to both contrast-enhanced CT and Doppler sonography in the
characterization of adnexal masses
[10]. The administration of
gadolinium is important because it may reveal solid elements not appreciated
on the precontrast T1- and T2-weighted images. About 10% of ovarian cancers
have a genetic basis, and most of these are related to mutations in the BRCA
gene. The association between breast and ovarian cancer in women with
mutations of the BRCA gene is rare but important to recognize, particularly in
patients with a strong family history. Women with BRCA mutations have a
56–87% lifetime risk of breast cancer and a 27–44% lifetime risk
of ovarian cancer. Patients with hereditary nonpolyposis colon cancer (Lynch)
syndrome are also significantly more likely to develop ovarian cancer.
View larger version (131K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 10C —45-year-old woman with colon cancer. T1-weighted axial MR image with
fat saturation shows masses (arrows) of high-signal-intensity masses
remain, consistent with blood products rather than fat.
|
|
View larger version (124K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 10D —45-year-old woman with colon cancer. T2-weighted axial MR image
shows masses (arrows) of generally intermediate signal intensity.
Such "shading," in association with T1-weighted findings, suggests
endometriosis; diagnosis confirmed at laparoscopy.
|
|
Benign Masses
Benign adnexal masses occur frequently, so it is not surprising that
adnexal masses in patients with nonovarian primary malignancies are commonly
incidental and benign. Imaging can confidently establish a specific diagnosis
in many cases. Mature cystic teratomas (dermoid cysts) are the most common
benign tumor of the ovary and are often found incidentally. The presence of
fat, toothlike calcification or Rokitansky nodules in an ovarian mass is
essentially diagnostic of a mature cystic teratoma
(Fig. 9). Endometriomas have
nonspecific CT characters and are one of the diseases that are better
characterized by MRI (Figs.
10A,
10B,
10C, and
10D). MRI typically shows
adnexal masses of high T1 signal intensity that do not suppress with fat
saturation and may be associated with low T2 signal. Fibrothecomas are
mesenchymal tumors rich in fibroblasts and collagen that account for
4–5% of all ovarian neoplasms
[11]. Fibrothecomas are
typically solid and relatively nonspecific in appearance on CT. Minimal
enhancement and low T2-signal intensity (presumably because of the presence of
collagen) are MRI features that help in further characterization (Figs.
11A,
11B, and
11C). Findings of Meig's
syndrome (ovarian fibrothecoma with ascites and pleural effusion) may also be
seen. Peritoneal inclusion cysts are collections of ovulatory ovarian fluid
usually around the ovary that are trapped by peritoneal adhesions. Typically,
there is a history of endometriosis, pelvic inflammatory disease, or pelvic
surgery, such as ovarian transposition (Figs.
12A and
12B). The diagnosis should be
suggested when a normal-appearing ovary is seen abutting in the wall of an
adnexal cyst that conforms to the outline of the pelvic cavity in a
premenopausal woman [12].
Recognition should result in conservative therapy rather than
salpingoophorectomy.
View larger version (133K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 11C —53-year-old woman with breast cancer. Axial T1-weighted image with
fat saturation after intravenous gadolinium shows mass (arrow) to be
minimally enhancing. Fibrothecoma confirmed at resection.
|
|
View larger version (152K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 12B —42-year-old woman with history of ovarian transposition before
administration of radiotherapy for cervical cancer. T2-weighted sagittal MR
image shows cyst conforms to outline of peritoneal cavity. Transposed but
otherwise normal ovary (arrow) is abutting posterior wall of cyst.
Findings are those of peritoneal inclusion cyst.
|
|
Conclusion
The differential diagnosis for adnexal masses seen in patients with primary
nonovarian malignancy consists of metastases to the ovaries, primary ovarian
malignancy, or incidental benign pathology. Knowledge of the nature, stage,
and genetic basis of the primary tumor may help in assessment. In general,
solid components favor metastases, but frequent exceptions occur; metastases
may be predominantly cystic and some primary ovarian cancers can be solid.
Incidental benign disease is also an important consideration, and MRI may be
particularly helpful in the characterization of entities such as
endometriosis, fibroma, and peritoneal inclusion cysts.
References
- Curtin JP. Management of the adnexal mass. Gynecol
Oncol 1994; 55:S42
-S46[CrossRef][Medline]
- Holtz F, Hart WR. Krukenberg tumors of the ovary: a
clinicopathologic analysis of 27 cases. Cancer1982; 50:2438
-2447[CrossRef][Medline]
- Renaud MC, Plante M, Roy M. Metastatic gastrointestinal tract
cancer presenting as ovarian carcinoma. J Obstet Gynaecol
Can 2003; 25:819
-824[Medline]
- Curtin JP, Barakat RR, Hoskins WJ. Ovarian disease in women with
breast cancer. Obstet Gynecol 1994;84
: 449-452[Abstract/Free Full Text]
- Brown DL, Doubilet PM, Miller FH, et al. Benign and malignant
ovarian masses: selection of the most discriminating gray-scale and Doppler
sonographic features. Radiology 1998;208
: 103-110[Abstract/Free Full Text]
- Hann LE, Lui DM, Shi W, Bach AM, Selland DL, Castiel M. Adnexal
masses in women with breast cancer: US findings with clinical and
histopathologic correlation. Radiology2000; 216:242
-247[Abstract/Free Full Text]
- Ferrozzi F, Tognini G, Bova D, Zuccoli G. Non-Hodgkin lymphomas of
the ovaries: MR findings. J Comput Assist Tomogr2000; 24:416
-420[CrossRef][Medline]
- Young RH, Hart WR. Metastases from carcinomas of the pancreas
simulating primary mucinous tumors of the ovary: a report of seven cases.
Am J Surg Pathol 1989;13
: 748-756[Medline]
- Piura B, Meirovitz M, Bartfeld M, Yanai-Inbar I, Cohen Y.
Peritoneal papillary serous carcinoma: study of 15 cases and comparison with
stage III–IV ovarian papillary serous carcinoma. J Surg
Oncol 1988; 68:173
-178[CrossRef]
- Kurtz A, Tsimikas JV, Tempany CMC, et al. Diagnosis and staging of
ovarian cancer: comparative values of Doppler and conventional US, CT, and MR
imaging correlated with surgery and histopathologic analysis—report of
the Radiation Diagnostic Oncology Group. Radiology1999; 212:19
-27[Abstract/Free Full Text]
- Bazot M, Ghossain MA, Buy JN, et al. Fibrothecomas of the ovary: CT
and US findings. J Comput Assist Tomogr1993; 17:754
-759[Medline]
- Kim JS, Lee HJ, Woo SK, Lee TS. Peritoneal inclusion cysts and
their relationship to the ovaries: evaluation with sonography.
Radiology 1997;204
: 481-484[Abstract/Free Full Text]
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Top
Abstract
Introduction
