Differential diagnosis of gynaecological "stained glass" tumours on MRI

Role of magnetic resonance imaging in the differentiation of mucinous ovarian carcinoma and mucinous borderline ovarian tumors

OBJECTIVE

This study was carried out to investigate the differentiation of mucinous borderline ovarian tumor from mucinous ovarian carcinoma using magnetic resonance imaging.

METHODS

We evaluated 77 women patients who underwent abdominal magnetic resonance imaging due to pelvic mass. magnetic resonance imaging was reviewed by an experienced radiologist. A total of 70 women patients were included in the study. The magnetic resonance imaging features were retrospectively evaluated and compared between the two pathologies.

RESULTS

There was no difference between the two groups in terms of maximum tumor size. Age at diagnosis was 56.29±11.92 in the mucinous ovarian carcinoma group and 44.74±13.60 in the mucinous borderline ovarian tumor group (p<0.05). A significant difference was found between the two groups, and it was observed that mucinous borderline ovarian tumors appeared in the younger age group compared to mucinous ovarian carcinomas. Presence of ascites, peritoneal dissemination, lymphadenopathy, and mural nodules was found significantly more frequently in mucinous ovarian carcinomas than in mucinous borderline ovarian tumors. Honeycomb appearance was found more frequently in mucinous borderline ovarian tumor patients than in mucinous ovarian carcinoma patients.

CONCLUSION

magnetic resonance imaging findings of these two pathologies overlapped considerably. Compared with mucinous borderline ovarian tumors, mucinous ovarian carcinomas frequently had mural nodules larger than 5 mm, larger tumor size, peritoneal dissemination, and abnormal ascites.

Ovarian Masses in Children and Adolescents: A Review of the Literature with Emphasis on the Diagnostic Approach

Most abdominal masses in the pediatric population derive from the ovaries. Ovarian masses can occur in all ages, although their incidence, clinical presentation and histological distribution vary among different age groups. Children and adolescents may develop non-neoplastic ovarian lesions, such as functional cysts, endometrioma, torsion, abscess and lymphangioma as well as neoplasms, which are divided into germ cell, epithelial, sex-cord stromal and miscellaneous tumors. Germ cell tumors account for the majority of ovarian neoplasms in the pediatric population, while adults most frequently present with epithelial tumors. Mature teratoma is the most common ovarian neoplasm in children and adolescents, whereas dysgerminoma constitutes the most frequent ovarian malignancy. Clinical manifestations generally include abdominal pain, palpable mass, nausea/vomiting and endocrine alterations, such as menstrual abnormalities, precocious puberty and virilization. During the investigation of pediatric ovarian masses, the most important objective is to evaluate the likelihood of malignancy since the management of benign and malignant lesions is fundamentally different. The presence of solid components, large size and heterogenous appearance on transabdominal ultrasonography, magnetic resonance imaging and computed tomography indicate an increased risk of malignancy. Useful tumor markers that raise concern for ovarian cancer in children and adolescents include alpha-fetoprotein, lactate dehydrogenase, beta subunit of human chorionic gonadotropin, cancer antigen 125 and inhibin. However, their serum levels can neither confirm nor exclude malignancy. Management of pediatric ovarian masses needs to be curative and, when feasible, function-preserving and minimally invasive. Children and adolescents with an ovarian mass should be treated in specialized centers to avoid unnecessary oophorectomies and ensure the best possible outcome.

Magnetic resonance imaging findings of cystic ovarian tumors: major differential diagnoses in five types frequently encountered in daily clinical practice

There are many types of ovarian tumors, and these different types often form cystic masses with a similar appearance, which can make their differentiation difficult. However, with the exclusion of rare ovarian tumors, the number of ovarian tumors encountered in daily practice is somewhat fixed. It goes without saying that magnetic resonance imaging (MRI) is useful for differentiating ovarian tumors. In this review, we summarize the differential diagnoses for each of the five types of MRI findings commonly encountered in daily practice. First, unilocular cystic masses without mural nodules/solid components include benign lesions such as serous cystadenoma, functional cysts, surface epithelial inclusion cysts, paratubal cysts, and endometriosis. Second, multilocular cystic ovarian lesions include mucinous tumors and ovarian metastases. It should be noted that mucinous tumors may be diagnosed as borderline or carcinoma, even if no solid component is observed. Third, cystic lesions with mural nodules that are unrelated to endometriosis include serous borderline tumor and serous carcinoma. Cystic lesions with solid components are more likely to be malignant, but some may be diagnosed as benign. Fourth, ovarian tumors deriving from endometriosis include seromucinous borderline tumors, endometrioid carcinoma, and clear cell carcinoma. These tumors sometimes need to be differentiated from serous tumors. Finally, cystic lesions with lipid contents include teratoma-related tumors. In mature cystic teratoma, mural nodules (called "Rokitansky protuberance" or "dermoid nipple") are sometimes seen, but they do not suggest malignancy. Some of these lesions can be diagnosed accurately by considering their characteristic imaging findings, their changes over time, MRI findings other than those of the primary lesion, and information from other modalities such as tumor markers. To ensure the optimal treatment for ovarian tumors, it is important to estimate the histological type as well as to diagnose whether a lesion is benign or malignant.

Useful preoperative examination findings to classify the grade of ovarian primary mucinous tumor

PURPOSE

To evaluate various imaging features on magnetic resonance imaging (MRI) and tumor markers and their utility to assess various grades of ovarian primary mucinous tumors (OPMTs): benign, borderline, or malignant.

METHODS

Ninety-five pathologically diagnosed OPMTs [53 benign, 24 borderline malignant (BM), and 18 malignant] were selected in this retrospective study. MRI features of the ovarian mass, namely the maximum diameter, honeycomb loculi, solid components (SC), stained-glass pattern, and signal intensity of the cyst on T1- (T1WI) and T2-weighted imaging (T2WI) with/without fat suppression, and preoperative STMs, namely carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, and CA125, were compared between the three tumor grades using univariate analysis. We also analyzed the findings to estimate the pathological diagnosis using classification tree (CT) analysis.

RESULTS

Maximum diameter, honeycomb loculi, SC, stained-glass pattern, signal intensity of the cyst [hyperintensity on both T1WI and T2WI (T1-hyper/T2-hyper), and hyperintense on T1WI and hypointense on T2WI (T1-hyper/T2-hypo)], and CEA and CA 19-9 concentrations were significantly different between the three tumor grades (p < 0.05). The concordance rate with the pathological diagnosis was the highest with diagnosis by the CT comprising T1-hyper/T2-hypo, CEA, and CA 19-9 and by the CT comprising T1-hyper/T2-hypo, CEA, and SC.

CONCLUSION

Four types of findings were important for OPMT grading. Lesions negative for both T1-hyper/T2-hypo and CEA suggest benign; lesions positive for T1-hyper/T2-hypo and negative for CA 19-9 or SC suggest BM; and lesions negative for T1-hyper/T2-hypo and positive for CEA, or positive for both T1-hyper/T2-hypo and CA 19-9 or SC suggest malignancy.

Can MRI features differentiate ovarian mucinous carcinoma from mucinous borderline tumor?

PURPOSE

Our purpose was to determine if MRI could be used to distinguish ovarian mucinous carcinoma (MC) from mucinous borderline tumor (MBT).

MATERIALS AND METHODS

This study included 63 consecutive patients with histopathologically proven ovarian mucinous neoplasms (11 MCs and 52 MBTs) who underwent preoperative contrast-enhanced MRI. MRI images were retrospectively reviewed and compared between the 2 pathologies.

RESULTS

The maximum tumor diameters (219.7 ± 80.8 mm vs. 177.4 ± 56.5 mm, p <  0.05) and maximum mural nodule (MN) diameters (41.7 ± 33.8 mm vs. 6.6 ± 8.9 mm, p <  0.01) were significantly larger in MCs than in MBTs. MNs larger than 5 mm (82 % vs. 29 %, p <  0.01) and abnormal ascites (45 % vs. 12 %, p <  0.05) were significantly more frequent in MCs than in MBTs. Apparent diffusion coefficient (ADC) values of MN were significantly lower in MCs than in MBTs (1.20 ± 0.25 × 10^-3 mm²/s vs. 1.61 ± 0.35 × 10^-3 mm²/s, p <  0.05). No significant difference was found in number of loculi, honeycomb sign, stained glass appearance, fluid-fluid level, thickened septa larger than 5 mm, peritoneal dissemination, or T2 hypointense microcysts between MCs and MBTs. T2 hypointense microcysts were observed only in 7 MBTs (13%).

CONCLUSION

MRI findings of these 2 pathologies overlapped considerably. Compared with MBTs, MCs exhibited larger tumor size, larger MN size, and lower ADC values of MN, and MCs more frequently had MNs larger than 5 mm and abnormal ascites. T2 hypointense microcysts might be a specific MRI finding in MBTs.

Quantitative analysis of ovarian cysts and tumors by using T2 star mapping

AIM

The aim of this study was to investigate the efficacy of T2 star (T2*) mapping in diagnosing ovarian cysts/ tumors.

METHODS

Pelvic magnetic resonance examinations including T2*WI were performed before surgery in 35 patients. The region of interest, consisted of a 10 mm² diameter circle, was set as much as possible inside ovarian tumors/cysts to measure T2*values, and mean T2* values were compared in ovarian cyst/tumor types, retrospectively. Diagnoses of 40 ovarian cysts/tumors were determined by pathological reports, in which 17 were endometriomas, 13 were mature cystic teratomas, 6 were mucinous cystadenomas and 4 were serous cystadenomas.

RESULTS

The average T2* values of endometrioma was 56.8 ± 8.7 ms (mean ± SEM), which was significantly lower than that of mucinous cystadenoma (334.2 ± 58.5 ms, mean ± SEM) or serous cystadenoma (237.0 ± 45.4 ms, mean ± SEM). There was no difference in T2* values between endometrioma and mature cystic teratoma (64.1 ± 22.6 ms, mean ± SEM). Receiver operating characteristics curve analysis revealed that optimal cut-off value for differential diagnosis of endometrioma and mucinous or serous cystadenoma was 149.2 ms as T2* value, which has an area under the curve of 0.95 (sensitivity = 92.4%, specificity = 78.6%).

CONCLUSION

T2* values were useful to diagnose various types of ovarian cyst/tumor.

Solidified mucinous tumor of the ovary presenting characteristic MRI finding

Mucinous tumors are a common ovarian cystic tumor, having a characteristic finding on MR imaging, the so-called stained glass appearance. We report a rare case of a solidified mucinous tumor of the ovary, which showed unique findings on MR images. The tumor demonstrated hypointensity on T2-weighted images, not stained glass appearance, mimicking ovarian fibrous tumor such as thecoma-fibroma. Histopathological examination confirmed solidified contents of the tumor with numerous septa and diagnosed mucinous borderline tumor/atypical proliferative tumor.

Magnetic resonance imaging of pediatric adnexal masses and mimics

Evaluation of adnexal masses in children and adolescents relies on imaging for appropriate diagnosis and management. Pelvic MRI is indicated and adds value for all adnexal masses when surgery is considered or when ultrasound findings are indeterminate. Specifically, features on MR imaging can help distinguish between benign and malignant lesions, which not only influences the decision between surgery and conservative treatment, but also the type of surgery to be performed, including potential use of fertility-sparing approaches with minimally invasive techniques. Larger size, younger age, presentation with precocious puberty or virilization, restricted diffusion in a solid mass, and rapid and strong enhancement of solid components are all features concerning for malignancy. In addition, distinctive MR imaging features of adnexal masses, combined with clinical and laboratory biomarkers, might suggest a specific histological diagnosis.

Usefulness of T2 star-weighted imaging in ovarian cysts and tumors

AIM

The aim of this study was to investigate the prevalence of hypointensity on T2 star-weighted imaging (T2*WI), which is useful for detecting hemosiderin, in endometriomas and other ovarian tumors. The efficacy of detecting adhesions around ovarian tumors was also investigated.

METHODS

Pelvic magnetic resonance (MR) examinations, including T2*WI, were carried out. The inclusion criteria were female patients with ovarian surgical treatments. One hundred seventeen patients with a total of 147 lesions were enrolled. Two radiologists retrospectively evaluated MR imaging (MRI) to predict ovarian pathology and the presence of adhesions. T2*WI hypointensity of the inside and outside along ovarian cysts/tumors was utilized to predict pathological diagnoses and the presence of adhesions, respectively. The kappa scores were calculated to measure interobserver agreement on MRI findings. The MRI interpretations were compared with the results of pathological investigation and surgical observations.

RESULTS

Hypointensity inside along the cyst walls on T2*WI was observed in 100 out of 106 lesions of endometriomas (94.3%), and three out of 41 non-endometrial ovarian cysts/tumors (7.3%). Four different patterns of T2*WI were observed in ovarian cysts/tumors. The kappa score regarding T2*WI hypointensity inside along the cyst walls was 0.633. Using conventional routine pelvic MRI, the sensitivity for detecting adhesions around ovarian cysts was 84.5%. By adding T2*WI, the sensitivity improved to 91.4% (P < 0.01). With conventional methods to predict adhesions, the kappa score was 0.660. After adding T2*WI to the conventional methods, the kappa score was 0.767.

CONCLUSION

Hypointensity on T2*WI was observed frequently in endometrioma. T2*WI also improved the sensitivity for detecting adhesions around ovarian cysts/tumors.

Differentiation of epithelial ovarian cancer subtypes by use of imaging and clinical data: a detailed analysis

Background

Primary epithelial ovarian carcinoma is sub-classified into serous, mucinous, endometrioid and clear cell subtypes. Neoadjuvant chemotherapy has become an alternative treatment option past several years, as serous carcinoma, the most common subtype, is known as chemotherapy-sensitive tumor. On the other hand, mucinous and clear cell carcinoma are known as chemotherapy-resistive. Therefore, it may be meaningful to estimate subtype of ovarian carcinoma using imaging modality. The purpose of this study is to study whether CT or MRI can determine the subtypes of epithelial ovarian cancers.

Methods

The imaging and clinical findings obtained from 125 consecutive patients with primary ovarian carcinoma were retrospectively analyzed. Forty-four of the patients had serous carcinoma; 13, mucinous carcinoma; 53, clear cell carcinoma; and 15, endometrioid carcinoma. We studied the bilateralism, morphological type, tumor diameter, solid portion ratio, relative signal intensity on T2WI and DWI, contrast ratio, and endometriosis on MRI and the calcification, peritoneal dissemination and lymph node metastasis, clinical staging, and thromboembolism on CT. We also studied the tumor markers and serum calcium concentrations. Each parameter was statistically analyzed by univariate and multivariate analyses.

Results

Serous carcinoma showed a significantly higher incidence of bilateral disease, smaller tumor size, higher signal intensity on DWI, and less frequent hypercalcemia. The CA19-9 level was significantly higher in mucinous carcinoma, in which most of the tumors appeared as multilocular cystic masses. Clear cell carcinoma appeared as unilateral disease with a larger solid portion and hypercalcemia in younger patients. Endometrioid carcinoma only showed a lower incidence of intraperitoneal dissemination.

Conclusions

CT and MRI combined with clinical data especially tumor markers and presence of paraneoplastic syndrome could partly predict epithelial ovarian cancer subtypes.

MRI appearances of mucinous borderline ovarian tumors: pathological correlation

PURPOSE

The purpose of this study is to evaluate the MRI features of mucinous borderline ovarian tumors (MBOT).

MATERIALS AND METHODS

MRI morphology of 30 MBOT proven MBOT by surgery and pathology was retrospectively studied and correlated with the histopathological findings. On MRI, tumors were classified into three morphological categories: (i) unilocular cyst in five (17%) tumors. (ii) multilocular cyst in 23 (76%) tumors. (iii) solid mass in 2 (7%) tumors. MRI features of tumors were identified including the multilocularity (23/30, 77%), honeycomb loculi (15/30, 50%), signal discrepancy (different signal intensity on T1WI and T2WI) (19/30, 63%), thickened wall or septa (>3 mm) (16/30, 53%).

RESULTS

Intestinal type and endocervical type of MBOT, two distinctly histologic subtypes, were found in 20 (67%) and 10 (33%) tumors respectively. There were a higher prevalence of multilocularity (P = 0.026), honeycomb loculi (P = 0.025), and signal discrepancy (P = 0.024) in intestinal type than endocervical type of MBOT.

CONCLUSION

Typical MRI features of MBOT are large multilocular tumors with honeycomb loculi, heterogeneous signal intensity of the loculi, and thickened wall or septa.

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.

Diversity in size and signal intensity in multilocular cystic ovarian masses: new parameters for distinguishing metastatic from primary mucinous ovarian neoplasms

PURPOSE

To differentiate primary mucinous ovarian neoplasms from metastatic ones with MR using diversity in size and signal intensity of multilocular cystic masses.

MATERIALS AND METHODS

Twenty-eight cases of primary malignant or borderline mucinous malignant neoplasms and 14 metastatic ovarian tumors were retrospectively reviewed. We analyzed whether the tumor was unilateral or bilateral, the diversity in the size and signal intensity of each loculus in multilocular tumors, namely the size ratio of the smallest/largest loculus (size diversity ratio), and the standard deviation of the signal intensity at the level with the most varying signal on T2-weighted images within tumors (signal diversity ratio). We performed statistical analysis using the Mann-Whitney U-test.

RESULTS

Bilateral tumors were more commonly observed among metastatic tumors than primary mucinous tumors (2/28 in primary versus 11/14 in metastatic, P < 0.01). The size diversity ratio was higher in primary mucinous tumors than in metastatic tumors (mean, 50.2 versus 23.2; P < 0.01). The signal diversity ratio was also higher in primary mucinous tumors than in metastatic tumors (334.3 versus 231.2; P < 0.01).

CONCLUSION

Bilateral tumors were more common among metastatic tumors, which tended to be composed of cysts of uniform sizes and signal intensities compared with those of primary mucinous tumors.

The MRI features of histologically proven ovarian cystadenofibromas-an assessment of the morphological and enhancement patterns

OBJECTIVES

To assess the morphological and enhancement features of histologically proven cystadenofibromas (CAFs) on magnetic resonance imaging (MRI).

METHODS

Forty-seven histologically proven CAFs (42 benign, five borderline) were retrospectively reviewed. One benign CAF had a synchronous adenocarcinoma in the same ovary. The morphological, signal and enhancement characteristics on MRI were recorded.

RESULTS

The mean long axis diameter of the CAFs was 80 mm. The contralateral ovary was abnormal in 45 % of cases. A solid component was seen in 85 %, which returned low T2-weighted signal in 75 % of CAFs. Septa were seen in 74 % and one CAF was purely cystic. The majority of solid components and septa demonstrated enhancement that was less than the myometrium. Wash-in rates (WIR) of the solid tissue were available for measurement in nine patients with an average WIR of 3.2 l/s.

CONCLUSION

This is the largest series describing MRI appearances of histologically proven CAFs. They are typically complex adnexal lesions containing septa, cystic components and solid tissue. The majority of solid components demonstrate low T2 signal and minimal enhancement. Almost half of the cases have an abnormal contralateral ovary.

Adnexal masses in pregnancy

Adnexal masses are often seen in the gravid patient. With current advances in technology, an increased number of adnexal masses are incidentally discovered on antenatal screening ultrasonography examinations. Sonography is the first-line imaging modality for any adnexal mass. However, further evaluation with magnetic resonance imaging (MRI) may be critical for diagnosis. For example, MRI can determine whether a mass contains fat, which can be useful in the diagnosis of a teratoma. Characteristic features of nonneoplastic and neoplastic ovarian lesions seen on sonography and MRI will be discussed. Radiologic features that help distinguish benign from malignant neoplasms will be described. Additional lesions specific to the gravid state must be considered in the differential diagnosis when appropriate, such as hyperstimulated ovaries, hyperreactio luteinalis, theca lutein cyst, and luteomas.

Malignant or borderline mucinous cystic neoplasms have a larger number of loculi than mucinous cystadenoma: a retrospective study with MR

PURPOSE

To determine whether there is any correlation between the number of loculi and the pathological grade of malignancy in mucinous cystic tumors of the ovary.

MATERIALS AND METHODS

We retrospectively studied MR images of 67 pathologically proven mucinous cystic tumors of the ovaries. Of these 67 cases, 38 were cystadenomas and 29 were malignant lesions (18 borderline malignancy and 11 adenocarcinomas). We counted the number of loculi and measured the maximum diameter of masses on MRI. We compared the number, the maximum diameter, and the ratio of the number of loculi to the maximum diameter in each adenoma and malignancy using Student's t-test.

RESULTS

The mean number of loculi was 18.2 in cystadenoma and 80.9 in malignant lesions. The mean maximum diameter of tumors was 13.0 cm in cystadenoma and 18.7 cm in malignant lesions. The mean ratio of the number of loculi to the maximum diameter was 1.3 in adenoma and 5.4 in malignant lesions. The differences between the benign and malignant lesions were statistically significant in number (P = 0.001), maximum diameter (P = 0.011), and ratio (P = 0.002).

CONCLUSION

Ovarian mucinous neoplasm of borderline malignancy and mucinous adenocarcinomas had a larger number of loculi than adenomas.

MR findings of ovarian tumors with hormonal activity, with emphasis on tumors other than sex cord-stromal tumors

Sex cord-stromal tumors including granulosa cell tumor, thecoma, Sertoli stromal cell tumor and steroid cell tumor are noted for their hormonal activity. However, there are many kinds of ovarian tumors other than sex cord-stromal tumors and tumor-like conditions with endocrine manifestations. Cross-sectional imaging, especially MR, can provide precise features of ovarian tumors and uterine morphological change even in a clinically latent excess of estrogen. In this article, we demonstrate typical imaging findings of ovarian tumors with hormonal activity. We also shortly explain the mechanism of the virilization and hyperestrogenism caused by ovarian tumors and tumor-like conditions.

Magnetic resonance imaging of adnexal masses

Adnexal masses are common in women of all ages. A range of physiological and benign ovarian conditions that develop in women, especially in the reproductive age, and adnexal malignancies can be evaluated with magnetic resonance imaging (MRI). Management of women with adnexal masses is frequently guided by imaging findings; therefore, precise characterization of adnexal pathology should be performed whenever possible. Magnetic resonance imaging is useful in characterization of adnexal masses that are not completely evaluated by ultrasound because it can provide additional information on soft tissue composition of adnexal masses based on specific tissue relaxation times and allows multiplanar imaging at large field of view to define the origin and extent of pelvic pathology. The patients most likely to benefit from MRI are pregnant women and those who are premenopausal and have masses that have complex features on ultrasound but do not have raised cancer antigen 125 tumor marker levels. The overlap in imaging appearance among different cell type malignancies makes it difficult to predict exact histology based on MRI appearance; however, MRI has a high accuracy in differentiating benign from malignant masses. Teratomas, endometriomas, simple and hemorrhagic cysts, fibromas, exophytic or extrauterine fibroids, and hydrosalpinges can be diagnosed with high confidence. In this article, the authors review the histopathologic background and MRI features of adnexal masses and discuss the role of MRI in the differentiation of benign from malignant adnexal pathologies.

MR imaging evaluation of the adnexa

MR imaging has become an important tool in the evaluation of patients with adnexal disease, and its role continues to evolve. Some benign entities can be diagnosed by MR imaging with a high grade of confidence, such as teratomas, endometriomas, simple and hemorrhagic cysts, fibromas, and hydrosalpinx. In cases of malignant lesions, MR imaging may be more accurate than other modalities for lesion characterization, staging, and follow-up.

Developing an MR imaging strategy for diagnosis of ovarian masses

Magnetic resonance (MR) imaging provides useful information for characterization of various ovarian masses as neoplastic or nonneoplastic and, when neoplastic, on a spectrum from benign to malignant. The use of MR imaging for diagnosis of ovarian masses includes consideration of morphologic characteristics and signal intensity characteristics on T1- and T2-weighted images. The morphologic characteristics of cystic masses, cystic and solid masses, and predominantly solid masses provide important information. In general, cystic masses represent benign tumors, whereas cystic and solid masses are strongly associated with malignancy. Predominantly solid masses include benign, borderline malignant, and malignant tumors. T1-weighted images provide useful information for characterization because hemorrhagic adnexal masses (eg, endometriotic cyst) and cystic teratomas can be correctly diagnosed when the mass has high signal intensity. Significant low signal intensity in solid masses on T2-weighted images is indicative of fibrothecomas and Brenner tumors because extensive fibrous tissue produces significant low signal intensity on T2-weighted images. A strategy for diagnosis of ovarian masses with MR imaging incorporates signal intensity characteristics into morphologic characteristics.

Functioning ovarian tumors: direct and indirect findings at MR imaging

There are many kinds of ovarian tumors and tumorlike conditions that produce estrogen or androgen. Magnetic resonance imaging can demonstrate not only ovarian tumors but also an enlarged uterus with a thick endometrium, even in cases of a clinically latent excess of estrogen. These clinical and indirect imaging findings can aid in the differential diagnosis of ovarian tumors. Granulosa cell tumor and thecoma are well-known estrogen-producing tumors. In pediatric or postmenopausal patients, they manifest as precocious pseudopuberty or postmenopausal bleeding, respectively. Conversely, Sertoli-Leydig cell tumor is representative of hormone-producing tumors that cause virilization. However, there are other functioning ovarian tumors besides the sex cord-stromal tumors. It is well known that metastatic ovarian tumors often have androgen-producing stroma and that mucinous cystadenoma sometimes produces estrogens. Most other ovarian tumors can produce sexual hormones in their stroma. In addition, some endocrinologic abnormalities (eg, polycystic ovary syndrome) also cause virilization.

Cystadenoma of the liver with ovarian-like stroma: case report

Cystadenomas are rare benign tumors with malignant potential. A 36-year-old woman presented with a 20-cm cystic mass in the left lobe of the liver. Surgery confirmed the diagnostic imaging findings. We present a case of cystadenoma of the liver with ovarian-like stroma and its associated radiologic characteristics.

Computed Tomography and Magnetic Resonance Imaging Findings in Cases of Dermoid Cyst Coexisting with Surface Epithelial Tumors in the Same Ovary

OBJECTIVE

The purpose of this work was to describe the computed tomography (CT) and magnetic resonance imaging (MRI) findings in cases of dermoid cysts coexisting with surface epithelial tumors in the same ovary.

METHODS

The pathologic reports of 141 dermoid cysts, 97 mucinous and 35 serous tumors were reviewed. The CT and/or MR images in the cases with a dermoid cyst and a surface epithelial tumor coexisting in the same ovary were analyzed.

RESULTS

Eleven cases of mucinous tumors (6 benign, 3 low-grade, and 2 malignant) coexisted with dermoid cysts. Mucinous tumors were found in coexistence with 11.3% of dermoid cysts, and dermoid cysts were found in coexistence with 7.8% of mucinous tumors. In 10 cases, 3 radiologic patterns were observed: small fatty foci in the septa of the cystic tumor, an adjacent fat-containing component and a septated cystic component, and a dermoid cyst with no detectable mucinous tumor component. No histopathologically specific differences were observed between these groups. Small amounts of mucinous components were difficult to detect, but small fatty foci were easily detected. In 1 case, mucinous carcinoma formed a mass lesion in the wall of the dermoid cyst.

CONCLUSIONS

The coexistence of these two neoplasms was not rare. If a dermoid cyst accompanies a multiseptated cyst and if the multiseptal cyst contains fatty foci, these two components may be associated. Recognizing the potential for the coexistence of these two neoplasms in the same ovary is essential for making a correct diagnosis.

MR imaging of müllerian mucinous borderline tumors arising from endometriotic cysts

This report describes MR findings of müllerian mucinous borderline tumors, pathologically proven to have arisen from endometriotic cysts, in three patients. They were unilocular or paucilocular masses with mural nodules. Cystic components showed hyperintensity on both T1- and T2-weighted images, simulating clear cell or endometrioid carcinomas arising from endometriotic cysts. Mural nodules showed prominent high signal intensity on T2-weighted images. Correlation with pathologic findings suggests that this hyperintensity reflects intraluminal mucinous material and stromal edema.

Severe spontaneous ovarian hyperstimulation syndrome with MR findings

We describe a case of severe spontaneous ovarian hyperstimulation syndrome (OHSS) with MR findings. MR scans showed bilateral symmetric enlargement of ovaries with multiple cystic changes, giving the classic "wheel-spoke" appearance. There was no definite abnormally thickened or enhanced wall, but there was internal hemorrhage in some chambers. To avoid unnecessary laparotomy, we emphasize the importance of careful diagnosis to differentiate spontaneous OHSS from ovarian cystic neoplasms.

MRI of gynaecological solid masses

Differential diagnosis of gynaecological masses is sometimes difficult, as there are so many histological types. However, magnetic resonance characteristics of some gynaecological tumours have been reported past several years. On the basis of the recent literature, we have made a decision tree for differential diagnosis of solid gynaecological tumours, in which there are some important divergences. Bilateral disease and invasive growth are malignant signs in most cases. Specific findings for different tumour types include: fibrovascular septa in dysgerminomas; preserving ovarian follicles in round cell tumours; pseudolobular patterns in young patients in sclerosing stromal tumours; and extremely hypointense masses on T2WI in Brenner tumours. Distinguishing between sex-cord stromal tumours, Brenner tumours and metastatic tumours may be hard, however, especially in middle age, because they all tend to show well-demarcated, hypointense masses on T2WI. Disproportionately clear zonal anatomy of the uterus, enlarged uterus and thickened endometrium, which are indirect findings of oestrogen-producing tumours, are useful diagnostic findings in children and postmenopausals.