CT and MR imaging of ovarian tumors with emphasis on differential diagnosis

MRI appearances of pure epithelial papillary serous borderline ovarian tumours

Borderline epithelial ovarian tumours (BOT) represent 15-20% of all non-benign ovarian epithelial neoplasms. Compared to malignant ovarian tumours, they usually present at a younger age and carry a far superior prognosis. Fertility-conserving surgery is an important treatment option for patients with BOT. Ultrasound and CT are both widely available and play roles in the initial investigation and staging of BOT, respectively. However, lack of soft-tissue contrast limits their ability to characterize BOT. MRI can facilitate recognition of pure epithelial serous BOT (SBOT), including the cystic papillary and surface papillary subtypes. An abundance of hyperintense papillary projections with low signal internal branching and ovarian stroma preservation with a hypointense ovarian capsular margin on T2-weighted imaging are features strongly suggestive of SBOT. In this review we will discuss the general morphological features of SBOT, the benefits and drawbacks of ultrasound and CT in the initial work-up, and the principal MRI features enabling recognition of surface papillary and cystic papillary SBOT.

Lesions of the ovary with T1-hypersignal

Pelvic magnetic resonance imaging (MRI) has been used successfully to diagnose ovarian masses that cannot be adequately evaluated using pelvic ultrasound. T1 hyperintensity is a common finding in an ovarian mass and has important diagnostic implications. The aims of this review are to list the substances that may produce high signal intensity on T1-weighted MRI, to explain the physical basis for causes of the high T1 signal intensity, and to describe common and uncommon T1 hyperintense ovarian lesions. The morphological findings, the imaging features of the additional sequences, and clinical variables can help in the differential diagnosis, and in some cases, enable a specific diagnosis, leading to appropriate management of the patient.

Differentiation of ovarian cancers from borderline ovarian tumors on the basis of evaluation of tumor vascularity in multi-row detector computed tomography--comparison with histopathology

OBJECTIVE

The aim of this study was to evaluate the feasibility of multi-detector row computed tomography (MDCT) in the differentiation between borderline ovarian tumors and ovarian cancer on the basis of tumor morphology and specific features of tumor vascularity in correlation with the results at pathology.

METHODS

A triphasic MDCT protocol was used for the analysis of tumor vascularity. The following features were taken into account: (1) The number of vessels in papillary projections, solid-tissue component, and septa (2 vs >2), (2) serpentine and chaotic configuration of vessels, (3) presence of microaneurysms, and (4) presence of arteriovenous microfistulas. Masses with at least 3 of 4 features were considered ovarian cancer (group A) and masses with 2 features or less as borderline tumor (group B). Radiological findings were compared with results of postoperative pathology.

RESULTS

Pathologic vessels were found in all 56 patients. Thirty-two patients were included in group A and 24 in group B. The results of pathology were as follows: in group A: 31 malignant tumors, including 31 ovarian carcinomas and 1 benign cystadenoma; in group B: 22 borderline ovarian tumors, 1 benign cystadenoma, and 1 ovarian cancer.

CONCLUSIONS

Morphological evaluation of tumor vascularity in MDCT seems to be an efficient method of differentiating between borderline ovarian tumors and ovarian carcinomas. Because of a small number of cases in the current study, a further research seems justified to confirm our results. The presented MDCT-angiographic criteria showed high sensitivity (97%) and specificity (96%) in differentiation of borderline ovarian tumors and ovarian cancers as compared with pathology. The presented CT-angiographic criteria of malignancy showed an excellent interobserver agreement.

Magnetic resonance imaging of pediatric pelvic masses

Both benign and malignant pelvic masses are encountered in the pediatric population. Although ultrasonography remains the modality of choice for initial evaluation of a pediatric pelvic mass, in selected cases magnetic resonance (MR) imaging can add important diagnostic information. MR imaging has several advantages over ultrasonography and computed tomography, including superior contrast resolution and an ability to characterize abnormalities based on unique tissue characteristics. MR evaluation assists in lesion characterization, presurgical planning, and staging when a malignancy is suspected. MR imaging also offers a nonionizing imaging modality for long-term follow-up of patients undergoing therapy for malignant pelvic masses.

Unique features and insights from mucinous tumors of ovary in childhood: clinicopathological study of 15 cases including four premenarchal cases

Mucinous tumors of ovary are primarily diagnosed in middle-aged and elder woman. They are very infrequent in the first two decades of life and exceedingly rare in premenarchal girls. We reviewed the past 20 years of our institutional pathology files and studied the clinicopathological features of the childhood ovarian mucinous tumor cases. The study concluded that ovarian mucinous tumor cases in childhood, including premenarchal cases, may not be as rare as people previously estimated and discovered some unique features of the tumors in this age group that are beneficial for better prognosis prediction and clinical management, as well as better understanding of pathogenesis of ovarian epithelial tumors.

Algorithmic approach to solid adnexal masses and their mimics: utilization of anatomic relationships and imaging features to facilitate diagnosis

Solid adnexal masses, while less common than their cystic counterparts, may present a challenge for radiologists given the wide range of histologic entities that occur in this region. Pelvic masses, especially when large, can seem overwhelming at first but application of an algorithmic approach allows for more confident assessment. This approach focuses first on the use of anatomic relationships and interactions of various pelvic structures to localize the mass' origin. For instance, the directionality of ureteral displacement can suggest if a mass is intra or extraperitoneal. Then, key discriminating imaging features, such as the presence of fat, hypervascularity, or low T2 signal on magnetic resonance imaging (MRI) can be applied to further narrow the list of diagnostic possibilities. Entities such as leiomyomas, nerve sheath tumors, congenital uterine anomalies, and vascular abnormalities (ovarian torsion or iliac vessel aneurysm) in particular are often accurately characterized with sonography and/or MRI. For solid adnexal masses in which a definitive diagnosis by imaging is not reached, information germane to clinicians regarding further management can still be provided, principally with regard to surgical vs. nonsurgical treatment.

Pelvic MRI as the "gold standard" in the subsequent evaluation of ultrasound-indeterminate adnexal lesions: a systematic review

OBJECTIVE

Incidentally discovered adnexal masses are common, posing a challenging diagnostic problem because imaging features of benign and malignant overlap. Thus, once an adnexal lesion has been detected, the primary goal of further imaging is accurate tissue characterization resulting in surgery only for lesions that are indeterminate or frankly malignant. This study aims to conduct a systematic review, following the PRISMA guidelines, and critically appraise pelvic MR Imaging as the preferred advanced second imaging test, as regards detection of ovarian cancer and assessment of indeterminate adnexal masses, with respect to pre-operatively improving the assignment of these patients to the appropriate level of care.

METHODS

A comprehensive computerized systematic literature search of English language studies was performed (from 2002 to 2012) of PubMed, EMBASE, Scopus, Evidence Based Medicine Reviews (Cochrane Database and Cochrane Central Register of Controlled Trials), and Google Scholar. Relevant article reference lists were hand searched.

RESULTS

Computerized database search revealed 37 citations of relevance, 10 of which fulfilled the inclusion/exclusion criteria. From the aforementioned, 8 articles were acquired (2 authors were contacted but did not respond) as well as assessed with AHRQ, QUADAS, and STARD evaluation tools. Finally, 6 papers (5 prospective and 1 retrospective) were included in the systematic review.

CONCLUSIONS

MRI with intravenous (IV) contrast administration provides the highest post-test probability of ovarian cancer detection. However, the preponderant contribution of MRI in adnexal mass evaluation is its specificity because it provides confident diagnosis of many benign adnexal lesions.

Ovarian Sertoli-Leydig cell tumors: MRI findings and pathological correlation

Background

To investigate the magnetic resonance imaging (MRI) characteristics of ovarian Sertoli-Leydig cell tumors (SLCT).

Methods

The clinical, MRI and pathological findings of five cases of SLCT were reviewed retrospectively. MRI appearances of tumors including laterality, shape and size, architecture, wall, septa and vegetation, signal intensity and contrast-enhancement pattern were evaluated and correlated with pathological findings.

Results

Two tumors were solid which appeared as low signal intensity on T1-weighted imaging (T1WI) and moderate on T2-weighted imaging (T2WI) with multiple small cysts in one of them. The remaining three SLCT were multilocular cystic with the irregularly thickened wall and septa, and with solid area and mural nodules in one of them. The cystic components had the same signal intensity as urine. All the solid components were intensely enhanced after administration of contrast medium. All five tumors were pathologically intermediate differentiation and at FIGO stage I.

Conclusions

SLCT demonstrate variable MRI morphological appearances. However, the irregularly thickened wall and septa, the moderate T2WI signal intensity and obvious enhancement in the solid components are three MRI features.

Ovarian mucinous cystadenoma coexisting with benign Brenner tumor: MR imaging findings

PURPOSE

The purpose of this study was to describe the MR imaging findings of ovarian mucinous cystadenomas coexisting with benign Brenner tumors.

MATERIALS AND METHODS

MR images with a 1.5-T unit obtained in five consecutive patients (age range, 51-72 years; mean age, 61 years) with surgically confirmed ovarian mucinous cystadenomas coexisting with benign Brenner tumors were retrospectively reviewed for the presence, configuration, and signal intensity of cystic and solid components of the lesions.

RESULTS

Tumors ranged in size from 7.5 to 22.1 cm (mean, 13.5 cm). In four patients (80%), the size of mucinous cystadenoma (range 6.4-22.1 cm; mean, 12.5 cm) was larger than that of Brenner tumor (range 0.2-9.1 cm; mean, 2.8 cm). All patients (100%) had cystic, and three (60%) had solid components. Four patients (80%) showed multilocular cystic, and one (20%) showed unilocular cystic appearance. MR imaging findings were classified into three patterns: (1) a bulky solid mass adjacent to the cystic component, (2) a mural nodule at the periphery of the cystic component, and (3) a cystic component without a detectable solid component. All four multilocular cystic areas exhibited "stained glass" appearances on both T1- and T2-weighted images, and all three solid areas showed homogeneous hypointensity on T2-weighted images.

CONCLUSION

Mucinous cystadenomas were often larger than the coexisting benign Brenner tumors. Mucinous cystadenomas coexisting with benign Brenner tumors should be considered when multilocular or unilocular cystic components are accompanied by homogeneously hypointense solid components on T2-weighted images.

MRI of ovarian masses

MRI provides exquisite views of the pelvic anatomy through its high spatial resolution and tissue contrast, and as such plays a key role in the work up of ovarian lesions, identifying features that distinguish benign and malignant lesions. In the case of primary tumors it enables local staging and detection of metastatic disease to help guide management options such as complex surgery or the consideration of neoadjuvant chemotherapy. Functional MRI techniques such as diffusion-weighted MRI (DW-MRI), dynamic contrast-enhanced MRI (DCE-MRI) and tumor-selective molecular imaging are currently being evaluated as possible predictive and prognostic biomarkers in the context of ovarian malignancy, and may play a larger role in routine clinical practice in the future. Herein we provide an overview of the conventional and advanced MRI techniques used to characterize ovarian masses and of the role that MR plays in the staging, treatment selection and follow up of patients with ovarian cancer.

Ovarian fibromas: MR imaging findings with emphasis on intratumoral cyst formation

PURPOSE

The purpose of this study was to assess MR imaging findings of ovarian fibromas with emphasis on intratumoral cyst formation.

MATERIALS AND METHODS

MR images with a 1.5-T unit obtained in 17 consecutive patients (age range, 18-87 years; mean age, 58 years) with 17 histologically proven ovarian fibromas were retrospectively reviewed for the size, configuration, signal intensity of solid components, and presence of cystic degeneration and edema within tumor. Size, number, and location of intratumoral cysts were also assessed.

RESULTS

The maximum diameter of tumors ranged from 3.3 to 19.1cm (mean, 10.9 cm). Seven (41%) tumors were multinodular. On T2-weighted images, solid components of tumors were heterogeneously mixed hypo- and hyperintensity in 16 (94%) tumors. Nine (53%) tumors demonstrated cysts and 16 (94%) demonstrated edema within tumor. The maximum diameter of the largest cysts ranged from 1.0 to 13.2 cm (mean, 6.4 cm), and the number of cysts per tumor ranged from 1 to 60 (mean, 15.6). Of the nine tumors with cystic formation, the predominant location of the cysts was peripheral in five (56%), exophytic in two (22%), central (11%) in one, and diffuse in one (11%).

CONCLUSION

Peripheral or exophytic cyst formation may be characteristic MR imaging features with ovarian fibromas.

Burkitt's Lymphoma Presented as Advanced Ovarian Cancer without Evidence of Lymphadenopathy: CT and MRI Findings

Burkitt's lymphoma is a rare non-Hodgkin's lymphoma which can occasionally involve the ovary and may cause confusion for the clinician since its presentation might mimic other much more frequent tumors. We present a case of a 23-year-old woman with sporadic Burkitt's lymphoma presented as advanced ovarian cancer with bilateral ovarian masses, peritoneal carcinomatosis, ascites, and marked elevation of CA-125. Liver involvement and atypical bone lesions, such as the cranial vault and the iliac wing, were also detected without evidence of lymphadenopathy. We describe the MRI and CT findings of simultaneous ovarian and bone lesions, which have never been reported in literature in a patient with Burkitt's lymphoma, before and after one cycle of chemotherapy. In evaluating any ovarian neoplasm in a young woman, Burkitt's lymphoma should be considered as a possibility, particularly if associated with bone lesions. MRI is the most useful tool to characterize the ovarian lesions and suggest the diagnosis before the histopathological results.

[Diagnosis and treatment of the epithelial ovarian cancer at the West African Cancer Center of Dakar]

INTRODUCTION

Epithelial ovarian cancer are the most frequent of ovarian cancer, their prognosis is very bad. The aim of this study is to describe the diagnosis, the treatment and to assess the survival rate of the patients.

METHODS

It was a retrospective study realized at the Cancer Institute of Dakar from December 2000 to January 2007. We have collected 117 patients with epithelial ovarian cancer. The mean age was 49 years. Patients were comprised: 22 stage I, 32 stage II, 35 stage III and 26 stage IV. Primary surgery was performed to 34 patients and the other patients were treated with chemotherapy and surgery. The survival rate was assessed by Kaplan-Meier method and the Logrank test had allowed to compare the survival among age and optimal surgery.

RESULTS

Optimal surgery R0 was done in 20 cases and surgical resection R2 was performed in 45 cases. Pathological exam had found 65 serous cystadenocarcinoma, 28 mucinous cystadenocarcinoma and 21 endometrioid cystadenocarcinoma, one malignant tumor of Brenner. Overall survival at five years was 13.3%. The survival among optimal surgery was 16.3 and 2.3% for suboptimal surgery. There was no significant difference of the survival among patients who were less than 40 years old (P = 0.334).

CONCLUSION

Prognosis of epithelial ovarian cancer is worse in Senegal as like as in the world. To improve the survival of our patients, we must detect the early diagnosis of these tumors and to introduce the neoadjuvant chemotherapy before optimal surgery.

Differential Diagnosis of Borderline Ovarian Tumors from Stage I Malignant Ovarian Tumors using FDG PET/CT

PURPOSE

Borderline ovarian tumors (BOTs) are more common in young women of reproductive age, and exhibit a better prognosis than malignant ovarian tumors (MOTs). Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) were compared in their ability to differentiate BOTs from stage I MOTs.

METHODS

Among 173 patients who had preoperative FDG PET/CT due to ovarian neoplasms between November 2006 and March 2009, there were 13 patients with BOTs or stage I MOTs. For differential diagnosis of the two tumors, cancer antigen-125 (CA-125) level, the longest diameter of tumors, metabolic indices including maximum standardized uptake value (SUVmax), and volumetric indices including metabolic tumor volume (MTV) were compared, respectively.

RESULTS

The BOT group (n = 7) was comprised of five mucinous and two serous tumors, and the MOT group (n = 6) was comprised of three endometrioid, two clear cell and one mucinous tumors. Among the comparisons between two groups, SUVmax of the BOT group was significantly lower than that of the MOT group (2.9 ± 1.5 vs. 6.6 ± 2.9, p = 0.0223); otherwise, no significant difference was found in age, CA-125, diameter, or MTV. By receiver-operating characteristic curve analysis, SUVmax of 3.7 was the best cutoff value to differentiate BOTs from stage I MOTs, with a sensitivity of 83.3 % and specificity of 85.7, and the area under curve of 0.893 (p = 0.0001, 95 % CI: 0.601∼0.993).

CONCLUSIONS

We demonstrated that SUVmax could distinguish BOTs from stage I MOTs, with a high sensitivity and specificity. Metabolic indices determined by FDG PET/CT were more suitable than volumetric indices for differential diagnosis of the two tumors.

Multimodality imaging of ovarian cystic lesions: Review with an imaging based algorithmic approach

Ovarian cystic masses include a spectrum of benign, borderline and high grade malignant neoplasms. Imaging plays a crucial role in characterization and pretreatment planning of incidentally detected or suspected adnexal masses, as diagnosis of ovarian malignancy at an early stage is correlated with a better prognosis. Knowledge of differential diagnosis, imaging features, management trends and an algorithmic approach of such lesions is important for optimal clinical management. This article illustrates a multi-modality approach in the diagnosis of a spectrum of ovarian cystic masses and also proposes an algorithmic approach for the diagnosis of these lesions.

Ovarian adenofibromas and cystadenofibromas: magnetic resonance imaging findings including diffusion-weighted imaging

BACKGROUND

Ovarian adenofibromas (AF) and cystadenofibromas (CAF) belong to the surface epithelial-stromal tumors, and may appear as solid, or solid and cystic masses mimicking ovarian cancers.

PURPOSE

To evaluate the capability of magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) with apparent diffusion coefficient (ADC) measurement for the diagnosis of ovarian AF/CAF.

MATERIAL AND METHODS

Magnetic resonance manifestations of 13 cases of ovarian AF/CAF were retrospectively evaluated. DWI was obtained in all 13 lesions, and mean ADC values in 11 lesions were compared with those in solid portions of 27 ovarian cancers. Results Neither case with AF/CAF revealed high signal intensity on DWI, whereas all ovarian cancers showed high signal intensity on DWI. The ADC values in the solid portions of AF/CAF were significantly higher than those of ovarian cancers (P < 0.001). A cut-off value of 1.20 × 10(-3) mm(2)/s for AF/CAF had a sensitivity of 82%, specificity of 93%, positive predictive value of 82%, and negative predictive value of 93%.

CONCLUSION

DWI with ADC measurement may be helpful in differentiating AF/CAF from ovarian cancers.

Teratomas: a multimodality review

Germ cell tumors (GCTs) may occur in both children and adults and include a broad array of histologic subtypes, such as teratoma, seminoma (known as dysgerminoma in the ovary and germinoma in the pineal gland), choriocarcinoma, yolk sac tumor, embryonal cell carcinoma, and mixed GCT. In adults, GCTs occur most commonly in the gonads. In children, sacrococcygeal tumors predominate. Teratomas are a common form of GCT. They are defined histologically as containing tissues derived from all 3 germ cell layers: ectoderm, mesoderm (most teratomas contain fat, an imaging hallmark, which is a mesodermal derivative), and endoderm. Teratomas are also classified as mature or immature, depending on the degree of differentiation of its components, and in adults, immature tumors are more likely to exhibit malignant behavior.

Influences of multiple genetic polymorphisms on ovarian cancer risk in Malaysia

OBJECTIVE

The identification of high-risk individuals can help to improve early cancer detection and patient survival. Risk assessment, however, can only be accomplished if the risk factors are known. To date, the genetic risk factors for ovarian cancer, other than mutations in the BRCA1/2 genes, have never been systematically explored in Malaysia. The present study aims to identify from a panel of cancer-associated single-nucleotide polymorphisms (SNPs), those associated with ovarian cancer risk in Malaysia.

METHODS

A total of 768 SNPs associated with various cancers among Asians were identified through a search of the relevant literature, and these SNPs were then screened for their association with ovarian cancer. A total of 160 Malaysian subjects were recruited for the study, including both ovarian cancer patients and controls. Genotyping was carried out using Illumina BeadArray platform.

RESULTS

A panel of 45 SNPs that are significantly (p<0.05) associated with ovarian cancer risk was identified. These ovarian cancer-associated SNPs were located in genes implicated in various pathways of carcinogenesis. Of these 45 SNPs, 5 have been previously associated with either ovarian cancer risk or survival.

CONCLUSION

This study has identified a panel of 45 SNPs that are significantly associated with ovarian cancer in a Malaysian population.

Diagnostic accuracy of diffusion-weighted imaging with conventional MR imaging for differentiating complex solid and cystic ovarian tumors at 1.5T

Background

Preoperative characterization of complex solid and cystic adnexal masses is crucial for informing patients about possible surgical strategies. Our study aims to determine the usefulness of apparent diffusion coefficients (ADC) for characterizing complex solid and cystic adnexal masses.

Methods

One-hundred and 91 patients underwent diffusion-weighted (DW) magnetic resonance (MR) imaging of 202 ovarian masses. The mean ADC value of the solid components was measured and assessed for each ovarian mass. Differences in ADC between ovarian masses were tested using the Student’s t-test. The receiver operating characteristic (ROC) was used to assess the ability of ADC to differentiate between benign and malignant complex adnexal masses.

Results

Eighty-five patients were premenopausal, and 106 were postmenopausal. Seventy-four of the 202 ovarian masses were benign and 128 were malignant. There was a significant difference between the mean ADC values of benign and malignant ovarian masses (p < 0.05). However, there were no significant differences in ADC values between fibrothecomas, Brenner tumors and malignant ovarian masses. The ROC analysis indicated that a cutoff ADC value of 1.20 x10^-3 mm²/s may be the optimal one for differentiating between benign and malignant tumors.

Conclusions

A high signal intensity within the solid component on T2WI was less frequently in benign than in malignant adnexal masses. The combination of DW imaging with ADC value measurements and T2-weighted signal characteristics of solid components is useful for differentiating between benign and malignant ovarian masses.

Is MRI a useful tool to distinguish between serous and mucinous borderline ovarian tumours?

AIM

To analyse the morphological magnetic resonance imaging (MRI) features of borderline ovarian tumours (BOT) and to evaluate whether MRI can be used to distinguish serous from mucinous subtypes.

MATERIALS AND METHODS

A retrospective study of 72 patients who underwent BOT resection was undertaken. MRI images were reviewed blindly by two radiologists to assess MRI features: size, tumour type, grouped and irregular thickened septa, number of septa, loculi of different signal intensity, vegetations, solid portion, signal intensity of vegetations, normal ovarian parenchyma, and pelvic ascites. Statistical analysis was performed using Mann-Whitney and Fisher's exact tests. Logistic regression analysis was used to assess the predictive value of the MRI findings for histological subtypes.

RESULTS

At histology, there were 33 serous BOT (SBOT) and 39 mucinous BOT (MBOT). Predictive MRI criteria for SBOT were bilaterality, predominantly solid tumour, and the presence of vegetations, especially exophytic or with a high T2 signal (p < 0.01), whereas predictive MRI criteria for MBOT were multilocularity, number of septa, loculi of different signal intensity, and grouped and irregular thickened septa (p < 0.01). Using multivariate analysis, vegetations were independently associated with SBOT [odds ratio (OR) = 29.5] and multilocularity with MBOT (OR = 3.9).

CONCLUSION

Vegetations and multilocularity are two independent MRI features that can help to distinguish between SBOT and MBOT.

Diffusion-weighted MRI: a useful technique to discriminate benign versus malignant ovarian surface epithelial tumors with solid and cystic components

PURPOSE

To evaluate differences in apparent diffusion coefficient (ADC) values for the solid component of benign and malignant ovarian surface epithelial tumors with the goal of differentiating benign versus malignant ovarian tumors preoperatively.

MATERIALS AND METHODS

A total of 127 patients with 131 pelvic masses identified by ultrasound between January 2006 and January 2011 were enrolled in this study. 46 patients were diagnosed with benign tumors, and 85 patients were diagnosed with malignant pathologies. For all of the patients, routine spin-echo MRI and diffusion-weighted imaging were performed. ADC values were determined for all of the masses, and the mean ADC values for the benign and malignant tumors were analyzed using Student's t test. A P value <0.05 was considered statistically significant.

RESULTS

Mean ADC values associated with malignant ovarian surface epithelial tumors were significantly lower than the mean ADC values of the benign tumors. In addition, the range of ADC values associated with a 95% confidence interval did not overlap between the two groups. ROC analysis indicated that a cutoff ADC value of 1.25 × 10(-3) mm(2)/s was associated with 90.1% sensitivity and 89.9% specificity.

CONCLUSION

ADC values determined from 1.5 T MR DWI of benign and malignant ovarian masses were found to be significantly different.

Radiological manifestations of metastasis to the ovary

MRI is an effective tool for detection of ovarian neoplastic lesions. However, there are no highly specific radiological features that differentiate primary from metastatic ovarian masses. Histological diagnosis preoperatively is not always possible as there is a risk of disseminating an otherwise early stage primary ovarian cancer. The preoperative diagnosis of an ovarian lesion is therefore heavily dependent on the radiological features. The radiologist must rely on a combination of knowing the natural history of any known primary cancer, together with the radiological features such as bilaterality, mucinous appearance, pseudomyxoma as well as the clinical progress of the primary tumour in order to evaluate and predict the likelihood of metastatic disease. Even if a non-ovarian primary cancer is known, an ovarian mass cannot always be assumed to be a secondary lesion. Some tumours, such as BRAC-positive breast cancer, are known to have a high rate of concomitant primary ovarian cancer. Conversely, other tumours, such as gastric and appendiceal cancer, are known to have a high rate of ovarian metastatic disease. However, histology remains the only true way to determine an ovarian metastasis from a primary lesion.

Imaging features and pathologic characteristics of ovarian thecoma

OBJECTIVE

To analyze the imaging findings of ovarian thecoma and to better understand the tumor features based on aspect of computed tomography and magnetic resonance images.

METHODS

Nineteen ovarian thecomas confirmed by histopathologic examination were analyzed retrospectively. Image characteristics were analyzed and compared with those of the pathologic features.

RESULTS

The mean diameter of tumors was 9.6 cm. The masses were well defined (n = 17) or ill defined (n = 2) and appeared solid with cystic areas (n = 11), entirely solid (n = 4), or cystic with solid components (n = 4). On T2-weighted/spectral adiabatic inversion recovery (T2WI/SPAIR) images, 12 cases appeared isointense or slightly hyperintense. Of the 12 cases, 8 had patchy hypersignal areas. On computed tomographic images, 7 cases showed hypodensity or isodensity. All tumors exhibited mild enhancement. On pathologic examination, the tumor was composed of spindle cells with a moderate amount of cytoplasm.

CONCLUSION

Imaging manifestations of ovarian thecoma are various and nonspecific. However, a large, well-defined mildly enhanced solid mass with cystic areas and especially isointense or slightly hyperintense on T2WI/SPAIR sequence in pelvic cavity may suggest the diagnosis of ovarian thecoma.

Histologic, molecular, and cytogenetic features of ovarian cancers: implications for diagnosis and treatment

Ovarian epithelial carcinoma (OEC), the most common ovarian malignancy, is a heterogeneous disease with several histologic subtypes that show characteristic cytogenetic features, molecular signatures, oncologic signaling pathways, and clinical-biologic behavior. Recent advances in histopathology and cytogenetics have provided insights into pathophysiologic features and natural history of OECs. Several studies have shown that high- or low-grade serous, endometrioid, and clear cell carcinomas are characterized by mutations involving the TP53, K-ras/BRAF, CTNNB1, and PIK3CA genes, respectively. High-grade serous carcinomas, the most common subtype, often manifest with early transcoelomic spread of disease beyond the ovaries, whereas low-grade serous and mucinous carcinomas commonly manifest with early-stage disease, with a resultant excellent prognosis. On the basis of pathogenetic mechanisms, recent findings suggest a dualistic model of ovarian carcinogenesis consisting of types I and II. Type I (low-grade serous, mucinous, and endometrioid) cancers commonly arise from well-described, genetically stable precursor lesions (usually borderline tumors); manifest as large adnexal masses with early-stage disease; and have a relatively indolent clinical course, with an overall good prognosis. In contrast, type II carcinomas (high-grade serous, endometrioid, mixed, and undifferentiated variants) originate de novo from the adnexal epithelia, often demonstrate chromosomal instability, and have aggressive biologic behavior. Better knowledge of hereditary ovarian cancer syndromes and associated cytogenetic abnormalities has led to increased interest in novel biomarkers and molecular therapeutics. Genetic changes, pathologic features, imaging findings, and natural histories of a variety of histologic subtypes of OEC are discussed in this article.

Imaging of pediatric ovarian neoplasms

We review the clinical and imaging characteristics of the most common ovarian neoplasms in children and adolescents. Because of the widespread use of diagnostic imaging, incidental ovarian neoplasms might be encountered during the evaluation of abdominal pain, trauma or other indications and might pose a diagnostic dilemma. Conducting adequate imaging studies under these conditions is important, as management strategies differ according to the size and appearance of the lesion as well as the age of the patient. US dominates in gynecological imaging because of its excellent visualization, absence of ionizing radiation and sedation risks and comparatively low cost. For further examination of indeterminate lesions found using US, MRI is being used more progressively in this field, particularly for the evaluation of complex pelvic masses with the aim of distinguishing benign and malignant conditions and conditions requiring surgical intervention. CT is reserved primarily for tumor staging and follow-up and for emergency situations.

Ovarian squamous cell carcinoma arising from mature cystic teratoma

Preoperative diagnosis of malignant transformation of an ovarian mature cystic teratoma to squamous cell carcinoma is difficult due to nonspecific tumor markers and imaging findings. This is an interesting case presentation that has prior imaging that demonstrates imaging characteristics of the transformation of a mature cystic teratoma to squamous cell carcinoma.

Is CA-125 an additional help to radiologic findings for differentiation borderline ovarian tumor from stage I carcinoma?

BACKGROUND

Borderline ovarian tumors (BOTs) are difficult to differentiate from stage I carcinoma using radiological findings. Little is known about the correlation between CA-125 levels and radiological findings for predicting BOTs or carcinoma.

PURPOSE

To assess the role of CA-125, in addition to that of radiological findings, in differentiating BOTs from stage I carcinoma.

MATERIAL AND METHODS

The study received institutional review board approval, with waiver of informed consent. We evaluated 100 patients (two groups: BOT, 58 patients; stage I carcinoma, 42 patients) using radiological findings, including location and size of each tumor, number and size of septations, papillary projections and vegetations, peritoneal implants, ascites, and preoperative CA-125 levels. The differences in CA-125 levels according to bilateral location, solid components, and thickness of septations between the two groups were evaluated using the McNemar test. Correlations of CA-125 level to size and number of septations were evaluated by the independent sample t test.

RESULTS

No statistical correlation was found between CA-125 level and location, size, and number of septations between the two groups. Solid components within the tumors were similar in the two groups, but the CA-125 level was significantly higher in stage I carcinoma than in BOTs. The number of septations per tumor was similar in the two groups; thick septations were more frequent in stage I carcinoma than in BOTs, and a significantly higher titer of CA-125 was found in stage I carcinoma. Discriminant analysis of solid components and thickness of septations resulted in accurate diagnosis of 70.6% of the tumors (80.6% of BOTs and 69.7% of stage I carcinomas).

CONCLUSION

CA-125 levels for solid components and thickness of septations are lower in BOTs. These may be helpful in predicting the risk of carcinoma, even if BOTs cannot be conclusively differentiated from stage I carcinoma.

MRI of the female pelvis: a possible pitfall in the differentiation of haemorrhagic vs. fatty lesions using fat saturated sequences with inversion recovery

The use of fat-saturated techniques should be an integral part of the work-up of any T1-hyperintense structure in the female pelvis for tissue characterization and for differentiation of a fat-containing ovarian mature teratoma from a haemorrhagic lesion. Two cases with haematocolpos and haematometra are presented, respectively. The haemorrhagic content showed high signal both on T1- and T2-weighted images, whereas an unexpected signal decrease in the fat-saturated T2-weighted inversion-recovery sequence was encountered. This unspecific suppression of signal in tissues with similar T1 relaxation times as fat can lead to a diagnostic pitfall both in T1- and T2-weighted STIR pulse sequences. Furthermore, a loss of signal on T2-weighting may also be due to the phenomenon of "T2-shading" in T1-bright ovarian endometrioma. Therefore, the fat-specific spectral fat-saturation of T1-weighted images is strongly recommended for tissue characterization in gynaecological disease.

Characterization of complex adnexal masses: value of adding perfusion- and diffusion-weighted MR imaging to conventional MR imaging

PURPOSE

To retrospectively determine the value of adding perfusion-weighted (PW) and diffusion-weighted (DW) sequences to a conventional magnetic resonance (MR) imaging protocol to differentiate benign from malignant tumors.

MATERIALS AND METHODS

The institutional ethics committee approved this retrospective study and waived the requirement to obtain informed consent. MR images in 87 women (age range, 25-87 years) who underwent imaging before surgery for complex adnexal masses-excluding endometriomas and cystic teratomas-were analyzed. Conventional morphologic, perfusion, and diffusion MR criteria of malignancy were recorded. Three independent observers reviewed images in four steps: conventional MR images alone, conventional MR images and PW images combined, conventional MR images and DW images combined, and conventional, PW, and DW MR images combined. Receiver operating characteristic curve analysis was performed to compare the results of the readings. A recursive partitioning model was built to establish a multivariate decision tree.

RESULTS

There was almost perfect agreement for lesion characterization regardless of the reader experiment or step considered (κ = 0.811-0.929). Area under the receiver operating characteristic curve values were higher for conventional and DW images combined, conventional and PW images combined, and conventional, DW, and PW images combined compared with conventional MR images alone (P < .05). For all readers, the accuracy of conventional, PW, and DW imaging combined was higher than that of conventional MR imaging alone for benign masses (P < .01) but not for malignant masses (P = .24). The addition of both PW and DW images led to a correct change in the diagnosis in 19% (11 of 57 patients), 23% (13 of 57 patients), and 24% (14 of 57 patients) of cases for readers 1, 2, and 3, respectively, with no incorrect changes. Conventional, PW, and DW MR imaging criteria were combined to generate a decision tree giving an accuracy of 95%.

CONCLUSION

The addition of PW and DW sequences to a conventional MR imaging protocol improved the diagnostic accuracy in the characterization of complex adnexal masses.