Two case reports of ovarian clear cell carcinoma: Atypical MRI findings with a renal corticomedullary contrast-like appearance

The MR images of the two cases of ovarian clear cell carcinomas (CCCs), presenting as entirely solid-masses, revealed a band-like peripheral area and a geographic central area: The peripheral area images resembled those of the renal cortex, while the central area images resembled those of the renal medulla. Compared to the iliac muscle, the band-like peripheral area appeared iso-hyperintense on T2-weighted imaging (T2WI), isointense on unenhanced T1-weighted imaging (T1WI), hyperintense on diffusion-weighted imaging (DWI), and hypo-isointense on an apparent diffusion coefficient (ADC) map, with gradual enhancement on dynamic contrast-enhanced T1WI. The geographic central area of the tumor appeared hyperintense on T2WI, hypointense on T1WI, hypointense on DWI, and hyperintense on an ADC map, with less enhancement on dynamic contrast-enhanced T1WI. Simple total hysterectomy, salpingo-oophorectomy, and partial omentectomy were performed in both cases. Both tumors were entirely solid, and histopathological analysis revealed cancer cell proliferation accompanied by an increase in stromal fibrous tissue in the peripheral area. Edematous stroma and fibrosis were predominantly observed with minimal cancer cells in the central area. The patients were diagnosed with ovarian CCC (pT1a). The mechanism behind the appearance of peripheral and central areas with renal corticomedullary contrast in such cases remains unknown, and MRI can provide valuable insights for the differential diagnosis of epithelial ovarian cancer.

Endometriosis: assessment on O-RADS and risk of malignant transformation

Endometriosis is a common disease, affecting approximately 10% of women of reproductive age. Several intersecting guidelines and consensus statements provide information on imaging diagnosis and surveillance strategies for endometriomas. SRU consensus panel recommendations provide information on initial detection of endometriosis on routine pelvic imaging. Revised American Society of Reproductive Medicine (rASRM) classification, the #ENZIAN classification, and the deep pelvic endometriosis index (dPEI) aim to assess the overall extent of disease and assist in presurgical planning. The Ovarian-Adnexal Reporting and Data System (O-RADS) aims to risk stratify lesions evaluated with US or MR based on their imaging morphology, from typical benign lesions to atypical presentations and malignant transformation. Emerging data shows increased risk of ovarian cancer in patients with endometriosis, especially following menopause and in those patients with long standing endometriosis. (Chen et al. in Front Oncol. 14:1329133, 2024;Streuli et al. in Climacteric. 20:138-143, 2017;Secosan et al. in Diagnostics (Basel). 10:134, 2020;Inceboz in Womens Health (Lond Engl). 11:711-715, 2015;Cassani et al. in Maturitas. 190, 2024;Gemmell et al. in Hum Reprod Update. 23:481-500, 2017;Giannella et al. in Cancers (Basel). 13:4026, 2021;) Current O-RADS guidelines mandate follow-up of endometriomas up to 2 years with further follow-up based on clinical factors. No consensus guidelines exist for imaging surveillance of patients with deep endometriosis from a malignancy standpoint. This review explores the imaging appearance of endometriomas, imaging features of malignant transformation, surveillance strategies and gaps in current literature, and attempts to better understand the risk of malignancy and to encourage further research for long-term imaging surveillance of endometriosis patients.

Fallopian fimbriae entrapped in an ovarian endometriotic cyst mimicking malignancy: a case report

Ovarian endometriotic cysts are associated with an increased risk of clear cell and endometrioid carcinomas, as well as borderline neoplasms. Although contrast-enhancing nodules on magnetic resonance imaging (MRI) suggest malignancy, benign endometriotic cysts can also present with such features, complicating differentiation from malignancy. When malignancy is suspected, minimally invasive procedures, such as laparoscopic cystectomy, are typically avoided. However, preserving fertility and ovarian function warrants careful consideration when selecting invasive surgical procedures. From the perspective of selecting appropriate surgical approaches, accurate preoperative differentiation between benign and malignant ovarian tumors is essential. We present the first case of MRI showing fallopian fimbriae entrapped in an endometriotic cyst mimicking malignancy. A 49-year-old female presented with atypical genital bleeding. MRI revealed a right ovarian endometriotic cyst with a contrast-enhancing mural nodule (10 mm), suggestive of malignancy. The nodule demonstrated T2-weighted hypointensity equivalent to the cyst fluid without diffusion restriction. Laparotomy revealed the nodule as entrapped fallopian fimbriae within the endometriotic cyst, with no malignancy detected. In this case, the fallopian fimbriae entrapped in the endometriotic cyst appeared as an enhancing nodule because of their vascularity, mimicking malignancy. Fallopian fimbriae are inconspicuous structures that can produce false findings suggestive of malignancy, similar to other benign enhancing nodules, such as polypoid endometriosis and decidualization. However, their lack of diffusion restriction and low T2-weighted signal intensity may help distinguish them from malignancy. This knowledge is crucial for accurate diagnosis and avoiding unnecessary interventions.

Postmenopausal Endometriosis: Clinical Insights and Imaging Considerations

Endometriosis is a chronic systemic condition characterized by the presence of ectopic endometrial-like tissue outside of the uterus. It occurs most often in reproductive-aged patients and less frequently in postmenopausal women. In postmenopausal patients, endometriosis is more common in those undergoing hormone replacement therapy or taking tamoxifen. The risk of malignant transformation of endometriosis is higher in this older population, especially in those undergoing estrogen-only hormone replacement therapy. Many theories on the postmenopausal pathogenesis of endometriosis have been proposed, ranging from reactivation of premenopausal disease to de novo manifestation. Compared with premenopausal disease, postmenopausal endometriosis is typically less active and extensive, with fewer hemorrhagic components. Patients may be symptomatic, with chronic pelvic pain, or may receive the diagnosis after imaging performed for other indications such as an incidental ovarian lesion. Treatment is typically surgical resection or estrogen-blocking medications. Although the diagnosis requires pathologic confirmation, radiologists play an important role in diagnosing both benign endometriosis and malignant transformation. Pelvic US following a dedicated protocol is an accessible screening tool, with high sensitivity for diagnosis of bowel-invasive disease. MRI has better anatomic resolution and allows simultaneous characterization of adnexal and extrapelvic lesions, thereby providing excellent assessment for malignant transformation.

Endometriosis, a common but enigmatic disease with many faces: current concept of pathophysiology, and diagnostic strategy

Endometriosis is a benign, common, but controversial disease due to its enigmatic etiopathogenesis and biological behavior. Recent studies suggest multiple genetic, and environmental factors may affect its onset and development. Genomic analysis revealed the presence of cancer-associated gene mutations, which may reflect the neoplastic aspect of endometriosis. The management has changed dramatically with the development of fertility-preserving, minimally invasive therapies. Diagnostic strategies based on these recent basic and clinical findings are reviewed. With a focus on the presentation of clinical cases, we discuss the imaging manifestations of endometriomas, deep endometriosis, less common site and rare site endometriosis, various complications, endometriosis-associated tumor-like lesions, and malignant transformation, with pathophysiologic conditions.

MR Relaxometry for Discriminating Malignant Ovarian Cystic Tumors: A Prospective Multicenter Cohort Study

BACKGROUND

Endometriosis-associated ovarian cancer (EAOC) is a well-known type of cancer that arises from ovarian endometrioma (OE). OE contains iron-rich fluid in its cysts due to repeated hemorrhages in the ovaries. However, distinguishing between benign and malignant tumors can be challenging. We conducted a retrospective study on magnetic resonance (MR) relaxometry of cyst fluid to distinguish EAOC from OE and reported that this method showed good accuracy. The purpose of this study is to evaluate the accuracy of a non-invasive method in re-evaluating pre-surgical diagnosis of malignancy by a prospective multicenter cohort study.

METHODS

After the standard diagnosis process, the R2 values were obtained using a 3T system. Data on the patients were then collected through the Case Report Form (CRF). Between December 2018 and March 2023, six hospitals enrolled 109 patients. Out of these, 81 patients met the criteria required for the study.

RESULTS

The R2 values calculated using MR relaxometry showed good discriminating ability with a cut-off of 15.74 (sensitivity 80.6%, specificity 75.0%, AUC = 0.750, p < 0.001) when considering atypical or borderline tumors as EAOC. When atypical and borderline cases were grouped as OE, EAOC could be distinguished with a cut-off of 16.87 (sensitivity 87.0%, specificity 61.1%).

CONCLUSIONS

MR relaxometry has proven to be an effective tool for discriminating EAOC from OE. Regular use of this method is expected to provide significant insights for clinical practice.

Endometriosis in Menopausal Women-A New Age Is Coming? Literature Review

Endometriosis is a chronic inflammatory disease, characterized by the presence of ectopic endometrial tissue, that leads to dysmenorrhea, painful intercourse and infertility. The shift in paradigm from the previous belief that endometriosis exclusively impacts women of reproductive age has brought attention to the condition in both premenarchal and postmenopausal women. Currently, 2-4% of postmenopausal women have endometriosis. Many women experience menopausal symptoms during the peri- and postmenopausal periods and require extensive investigations and monitoring in order to avoid the recurrence of endometriosis symptoms or the risk of malignant transformation when treatment with menopausal hormones is elected. Our goal was to compile and present a clear and concise overview of the existing literature on postmenopausal endometriosis, offering an up-to-date and precise summary of the available information.

Manifestations of Ovarian Cancer in Relation to Other Pelvic Diseases by MRI

Imaging plays a pivotal role in the diagnostic approach of women with suspected ovarian cancer. MRI is widely used for preoperative characterization and risk stratification of adnexal masses. While epithelial ovarian cancer (EOC) has typical findings on MRI; there are several benign and malignant pelvic conditions that may mimic its appearance on imaging. Knowledge of the origin and imaging characteristics of a pelvic mass will help radiologists diagnose ovarian cancer promptly and accurately. Finally, in special subgroups, including adolescents and gravid population, the prevalence of various ovarian tumors differs from that of the general population and there are conditions which uniquely manifest during these periods of life.

Whole-tumor ADC histogram analysis for differentiating endometriosis-related tumors: seromucinous borderline tumor, clear cell carcinoma and endometrioid carcinoma

PURPOSE

To investigate the feasibility of whole-tumor apparent diffusion coefficient (ADC) histogram analysis for improving the differentiation of endometriosis-related tumors: seromucinous borderline tumor (SMBT), clear cell carcinoma (CCC) and endometrioid carcinoma (EC).

METHODS

Clinical features, solid component ADC (ADC_SC) and whole-tumor ADC histogram-derived parameters (volume, the ADC_mean, 10th, 50th and 90th percentile ADCs, inhomogeneity, skewness, kurtosis and entropy) were compared among 22 SMBTs, 42 CCCs and 21 ECs. Statistical analyses were performed using chi-square test, one-way ANOVA or Kruskal-Wallis test, and receiver operating characteristic curves.

RESULTS

A significantly higher ADC_SC and smaller volume were associated with SMBT than with CCC/EC. The ADC_mean was significantly higher in CCC than in EC. The 10th percentile ADC was significantly lower in EC than in SMBT/CCC. The 50th and 90th percentile ADCs were significantly higher in CCC than in SMBT/EC. For differentiating SMBT from CCC, AUCs of the ADC_SC, volume, and 50th and 90th percentile ADCs were 0.97, 0.86, 0.72 and 0.81, respectively. For differentiating SMBT from EC, AUCs of the ADC_SC, volume and 10th percentile ADC were 0.97, 0.71 and 0.72, respectively. For differentiating CCC from EC, AUCs of the ADC_mean and 10th, 50th and 90th percentile ADCs were 0.79, 0.72, 0.81 and 0.85, respectively.

CONCLUSION

Whole-tumor ADC histogram analysis was valuable for differentiating endometriosis-related tumors, and the 90th percentile ADC was optimal in differentiating CCC from EC.

The Endometriotic Neoplasm Algorithm for Risk Assessment (e-NARA) Index Sheds Light on the Discrimination of Endometriosis-Associated Ovarian Cancer from Ovarian Endometrioma

BACKGROUND

Magnetic resonance (MR) relaxometry provides a noninvasive tool to discriminate endometriosis-associated ovarian cancer (EAOC) from ovarian endometrioma (OE) with high accuracy. However, this method has a limitation in discriminating malignancy in clinical use because the R2 value depends on the device manufacturer and repeated imaging is unrealistic. The current study aimed to reassess the diagnostic accuracy of MR relaxometry and investigate a more powerful tool to distinguish EAOC from OE.

METHODS

This retrospective study was conducted at our institution from December, 2012, to May, 2022. A total of 150 patients were included in this study. Patients with benign ovarian tumors (n = 108) mainly received laparoscopic surgery, and cases with suspected malignancy (n = 42) underwent laparotomy. Information from a chart review of the patients' medical records was collected.

RESULTS

A multiple regression analysis revealed that the age, the tumor diameter, and the R2 value were independent malignant predicting factors. The endometriotic neoplasm algorithm for risk assessment (e-NARA) index provided high accuracy (sensitivity, 85.7%; specificity, 87.0%) to discriminate EAOC from OE.

CONCLUSIONS

The e-NARA index is a reliable tool to assess the probability of malignant transformation of endometrioma.

Ovarian clear cell carcinoma arising in a large endometrioma — A case report with pathological correlation and literature review

Endometriosis-associated ovarian cancer represents the most common form of malignancy associated with this benign disease. It has a better prognosis than most types of ovarian cancer, with endometrioid adenocarcinoma and clear cell carcinoma as the main histological types. Clinical presentation is usually nonspecific and tumor biomarkers can be misleading, since they can also be elevated in the presence of benign ovarian endometriosis. We report a case of a 52-year-old woman with known ovarian and deep pelvic endometriosis, who developed ovarian clear cell carcinoma within a large endometrioma. The imaging findings highlight the key role of magnetic resonance imaging in detecting suspicious features such as loss of the “T2 shading” sign, loss of high T1 signal of an endometrioma, or the presence of mural nodules. Early detection of these malignancies is fundamental for adequate surgical treatment and overall outcome.

MRI in the Diagnosis of Endometriosis and Related Diseases

Endometriosis, a common chronic inflammatory disease in female of reproductive age, is closely related to patient symptoms and fertility. Because of its high contrast resolution and objectivity, MRI can contribute to the early and accurate diagnosis of ovarian endometriotic cysts and deeply infiltrating endometriosis without the need for any invasive procedure or radiation exposure. The ovaries, which are the most frequent site of endometriosis, can be afflicted by multiple related conditions and diseases. For the diagnosis of deeply infiltrating endometriosis and secondary adhesions among pelvic organs, fibrosis around the ectopic endometrial gland is usually found as a T2 hypointense lesion. This review summarizes the MRI findings obtained for ovarian endometriotic cysts and their physiologically and pathologically related conditions. This article also includes the key imaging findings of deeply infiltrating endometriosis.

Endometriosis and Its Myriad Presentations: Magnetic Resonance Imaging-Based Pictorial Review

Endometriosis is a major cause of infertility and pain in females in the reproductive age group. It is a result of ectopic functional endometrial cells outside the uterus. It consists of a spectrum of findings from superficial to deep implants initiating a fibrotic response and resulting in adhesions. Diagnosis of endometriosis is based on clinical history, noninvasive and invasive techniques. The final diagnosis is based on laparoscopy with histopathological confirmation. Ultrasonography is the first line of investigation, followed by magnetic resonance imaging (MRI) in complex cases. MRI is a noninvasive, multiplanar technique that involves no radiation and provides excellent delineation of the disease process. As deep endometriosis has a similar low signal to adjacent normal organs, it can be easily overlooked by radiologists. They should be aware of the spectrum of diseases so as to provide a roadmap for the surgeons. A structured reporting system helps radiologists organize and standardize their reports.

Multimodality Imaging Approach to Ovarian Neoplasms with Pathologic Correlation

Ovarian neoplasms can be categorized on the basis of histopathologic features into epithelial surface cell tumors, germ cell tumors, sex cord-stromal tumors, and metastases. While their imaging appearance is often nonspecific, it closely parallels the gross pathologic appearance, and radiologic-pathologic correlation is helpful to aid in a deeper understanding of the subtypes. Epithelial cell neoplasms are the most common category, and they can be benign, borderline, or malignant. Specific subtypes include serous (most common), mucinous, seromucinous, endometrioid, clear cell, Brenner, and undifferentiated. High-grade serous cystadenocarcinoma accounts for the majority of malignant ovarian tumors and the most ovarian cancer deaths. While serous neoplasms are often unilocular and bilateral, mucinous neoplasms are larger, unilateral, and multilocular. Solid components, thickened septa, and papillary projections, particularly with vascularity, indicate borderline or malignant varieties. Endometrioid and clear cell carcinomas can arise within endometriomas. Fibrous tumors (cystadenofibroma, adenofibroma, fibroma or fibrothecoma, and Brenner tumors) demonstrate low T2-weighted signal intensity of their solid components, while teratomas contain lipid. The nonspecific imaging appearance of additional malignant ovarian germ cell tumors can be narrowed with tumor marker profiles. Sex cord-stromal tumors are often solid, and secondary signs from their hormonal secretion can be a clue to their diagnosis. The authors review the anatomy of the ovary and distal fallopian tube, the proposed origins of the histologic subtypes of tumors, the clinical features and epidemiology of ovarian neoplasms, and the applications of US, CT, and MRI in imaging ovarian neoplasms. The main focus is on the radiologic and pathologic features of the multiple ovarian neoplasm subtypes. An algorithmic approach to the diagnosis of ovarian neoplasms is presented. Online supplemental material is available for this article. ^©RSNA, 2020.

Endometriosis in the postmenopausal female: clinical presentation, imaging features, and management

Postmenopausal endometriosis is an important clinical entity which is likely under-recognized and in which the Radiologist can play a valuable role. In this review, we describe the clinical presentation and management of postmenopausal endometriosis, appraising the literature and providing case examples. Persons with postmenopausal endometriosis may present with symptoms including pelvic pain or dyschezia, but endometriosis may also be an asymptomatic, incidental finding. Women may or may not have a prior history of endometriosis or a history of symptoms consistent with it. Therapies and conditions which increase exogenous or endogenous estrogen, respectively, increase the risk. Endometriosis can be found in different locations throughout the body, and the possibility of malignancy should be assessed, especially in the postmenopausal population, where age increases cancer risk. Treatment may involve surgery or medical interventions. Guidelines describing appropriate imaging surveillance in these patients are lacking. In the postmenopausal population, Radiologists need to consider endometriosis as a diagnosis, recommend appropriate exams such as MRI and US, and suggest endometriosis-associated malignancies when appropriate, based on classic morphologic features.

Understanding malignant transformation of endometriosis: imaging features with pathologic correlation

PURPOSE

Transformation of benign endometriosis to endometriosis-associated ovarian carcinoma (EAOC) is rare; however, women with endometriosis are four times more likely to develop EAOC which can present 20 years earlier than de novo ovarian cancer. Presenting symptoms are often vague and the radiologist's role in recognizing EAOC is critical for early detection and treatment. Histopathologic evaluation remains the mainstay for definitive diagnosis.

METHODS

Using a case-based approach, this article will review the sonographic, CT, and MRI features of EAOC with an emphasis on MRI. Histopathologic correlation of benign and malignant endometriosis will be reviewed.

RESULTS

Multiple factors contribute to the malignant transformation of endometriosis including genetic alterations, hormonal influences, oxidative stress, and inflammation. Malignancy most often occurs in ovarian endometriomas with less common sites involving the rectovaginal septum, rectosigmoid colon, and abdominal wall scars. The most common pathologic subtypes are endometrioid adenocarcinoma and clear cell carcinoma. MRI is the most specific imaging modality for evaluating EAOC. Key MR features include solid enhancing nodules (accentuated by subtraction imaging), nodular septations, loss of T2 shading within the endometrioma, and diffusion restriction.

CONCLUSIONS

EAOC is a distinct disease that affects women with benign endometriosis at younger ages than classic ovarian cancer. Understanding the imaging features of malignant transformation of endometriosis is essential for early diagnosis and timely definitive treatment.

MR findings for differentiating decidualized endometriomas from seromucinous borderline tumors of the ovary

PURPOSE

Decidualized endometriomas (DEs) and seromucinous borderline tumors (SMBTs) exhibit similar MR findings including markedly hyperintense mural nodules within endometriotic cysts on T2-weighted images. The present study aimed to assess the efficacy of MR imaging for differentiating between DEs and SMBTs of the ovary.

MATERIALS AND METHODS

MR images of 8 DEs and 14 SMBTs were retrospectively assessed and compared according to pathologies.

RESULTS

With regard to quantitative assessments of mural nodules, the number and signal intensity ratios (SIRs) on T1-weighted images were significantly greater in DEs than in SMBTs (11.0 ± 8.4 vs. 4.3 ± 4.1, p < 0.05 and 2.36 ± 0.56 vs. 1.49 ± 0.27, p < 0.01, respectively), whereas the height was significantly lower in DEs than in SMBTs (4.5 ± 1.4 mm vs. 21.9 ± 11.4 mm, p < 0.01). However, there were no significant differences between DEs and SMBTs in the SIRs on T2-weighted images, SIRs on diffusion-weighted images, and apparent diffusion coefficient values. With regard to qualitative assessments of mural nodules, the lobulated margin, pedunculated configuration, and T2 hypointense core were significantly more frequent in SMBTs than in DEs (71% vs. 0%, p < 0.01; 86% vs. 0%, p < 0.01; and 43% vs. 0%, p < 0.05, respectively).

CONCLUSION

The number, height, SIRs on T1-weighted images, lobulated margin, pedunculated configuration, and T2 hypointense core of mural nodules within endometriotic cysts were useful MR findings for differentiating DEs from SMBTs.

Usefulness of subtraction pelvic magnetic resonance imaging for detection of ovarian endometriosis

Background

To minimize damage to the ovarian reserve, it is necessary to evaluate the follicular density in the ovarian tissue surrounding endometriosis on preoperative imaging. The purpose of the present study was to evaluate the usefulness of subtraction pelvic magnetic resonance imaging (MRI) to detect ovarian reserve.

Methods

A subtracted T1-weighted image (^subT1WI) was obtained by subtracting unenhanced T1WI from contrast-enhanced T1WI (^ceT1WI) with similar parameters in 22 patients with ovarian endometriosis. The signal-to-noise ratio (SNR) in ovarian endometriosis, which was classified into the high signal intensity and iso-to-low signal intensity groups on the T2-weighted image, was compared to that in normal ovarian tissue. To evaluate the effect of contrast enhancement, a standardization map was obtained by dividing ^subT1WI by ^ceT1WI.

Results

On visual assessment of 22 patients with ovarian endometriosis, 16 patients showed a high signal intensity, and 6 patients showed an iso-to-low signal intensity on T1WI. Although SNR in endometriosis with a high signal intensity was higher than that with an iso-to-low signal intensity, there was no difference in SNR after the subtraction (13.72±77.55 vs. 63.03±43.90, p=0.126). The area of the affected ovary was smaller than that of the normal ovary (121.10±22.48 vs. 380.51±75.87 mm², p=0.002), but the mean number of pixels in the viable remaining tissue of the affected ovary was similar to that of the normal ovary (0.53±0.09 vs. 0.47±0.09, p=0.682).

Conclusion

The subtraction technique used with pelvic MRI could reveal the extent of endometrial invasion of the normal ovarian tissue and viable remnant ovarian tissue.

The Sonographic Spectrum of Pelvic Endometriosis: Pearls, Pitfalls, and Mimics

Endometriosis is a common disease of reproductive-age women that is often first encountered with ultrasound. Therefore, familiarity with the variety of manifestations of endometriosis is important for appropriate diagnosis and management. The aim of this article is to review the spectrum of appearance of pelvic endometriosis and to discuss potential mimics on ultrasound. Given that magnetic resonance imaging is an important problem-solving tool in female pelvic imaging, magnetic resonance imaging correlation is also provided.

Comparison of endometriotic cysts and ovarian cancer in association with endometriotic cysts

OBJECTIVE

The aim of this study was to clarify the clinical, laboratory, and imaging findings of ovarian cancer in association with endometriotic cysts by detailed comparison of the findings of benign and malignant tumors.

METHODS AND MATERIALS

This was a retrospective study of 138 women who had an operation for ovarian tumors at the Department of Obstetrics and Gynecology of Kochi Health Sciences Center between September 1, 2011, and July 30, 2015. The ovarian tumors were divided into two groups: the benign group (endometriotic cysts) and the malignant group (ovarian cancer in association with endometriotic cysts).

RESULTS

Of the 138 patients, 28 had malignant disease, and 110 had benign endometriotic cysts. Patients in the malignant group were significantly older than patients in the benign group. The mean maximum tumor diameter was also significantly larger for the malignant tumors. Unilocular-solid and multilocular-solid type tumors were present in 25.0% and 75.0% of malignant tumors, and in 9.1% and 19.1% of benign tumors, respectively. The mean maximum solid component diameter and height were significantly larger in the malignant tumors than in the benign tumors. The solid components were present on the abdominal side of the cyst wall in 12.5% of benign tumors and in 51.9% of malignant tumors.

CONCLUSION

In elderly patients, the presence of large solid components in large endometriotic cysts, especially the abdominal side of the cyst wall, might suggest malignancy.

MICRO ABSTRACT

The aim of this study was to clarify the findings of ovarian cancer in association with endometriotic cysts by detailed comparison of the findings of benign and malignant tumors. The presence of solid components in large endometriotic cysts, especially the abdominal side of the cyst wall, might suggest malignancy.

European society of urogenital radiology (ESUR) guidelines: MR imaging of pelvic endometriosis

Endometriosis is a common gynaecological condition of unknown aetiology that primarily affects women of reproductive age. The accepted first-line imaging modality is pelvic ultrasound. However, magnetic resonance imaging (MRI) is increasingly performed as an additional investigation in complex cases and for surgical planning. There is currently no international consensus regarding patient preparation, MRI protocols or reporting criteria. Our aim was to develop clinical guidelines for MRI evaluation of pelvic endometriosis based on literature evidence and consensus expert opinion. This work was performed by a group of radiologists from the European Society of Urogenital Radiology (ESUR), experts in gynaecological imaging and a gynaecologist expert in methodology. The group discussed indications for MRI, technical requirements, patient preparation, MRI protocols and criteria for the diagnosis of pelvic endometriosis on MRI. The expert panel proposed a final recommendation for each criterion using Oxford Centre for Evidence Based Medicine (OCEBM) 2011 levels of evidence.

KEY POINTS

• This report provides guidelines for MRI in endometriosis. • Minimal and optimal MRI acquisition protocols are provided. • Recommendations are proposed for patient preparation, best MRI sequences and reporting criteria.

MR Imaging for Incidental Adnexal Mass Characterization

Incidentally detected adnexal masses are common, and the overwhelming majority of them are benign. As many of these adnexal masses are considered indeterminate at CT or US, a large number of benign oophorectomies occur. Of the malignant adnexal masses, high-grade primary ovarian neoplasms with fast doubling times and early dissemination are the most common. Due to their aggressive behavior, diagnosis of malignancy by interval growth on surveillance imaging represents an undesirable option. Immediate MR characterization allows for a decreased rate of benign oophorectomies and expedited triage of patients to definitive treatment when malignancy is suspected.

Transverse Relaxation Rate of Cyst Fluid Can Predict Malignant Transformation of Ovarian Endometriosis

Purpose:

Heme and iron accumulation due to repeated hemorrhage in endometriosis may contribute to a pivotal role in carcinogenesis. We evaluate the clinical application of MR relaxometry in a series of ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC).

Materials and Methods:

A prospective study of diagnostic accuracy was conducted among 82 patients (67 OE and 15 EAOC) to compare MR relaxometry and biochemical measurement of cyst fluid total iron concentration. Transverse relaxation rate R2 value was determined using a single-voxel, multi-echo MR sequence (HISTO) by a 3T-MR system. Phantom experiments were also performed to assess the correlation between the ex vivo R2 values and total iron concentrations.

Results:

Both the results of phantom experiments and in vivo human data confirmed that in vivo R2 values were highly correlated with total iron concentrations. Compared to OE, EAOC exhibit decreased in vivo R2 values and total iron levels, regardless of their age, menopausal status and cyst size. The use of in vivo R2 values retained excellent accuracy in distinguishing EAOC versus OE (sensitivity and specificity: 86% and 94%).

Conclusions:

We have demonstrated that MR relaxometry provides a noninvasive predictive tool to discriminate between EAOC and OE.

Diagnostic performance of MR imaging findings and quantitative values in the differentiation of seromucinous borderline tumour from endometriosis-related malignant ovarian tumour

OBJECTIVES

To evaluate the diagnostic performance of quantitative values and MRI findings for differentiating seromucinous borderline tumours (SMBTs) from endometriosis-related malignant ovarian tumours (MT).

METHODS

This retrospective study examined 19 lesions from SMBT and 84 lesions from MT. The following quantitative values were evaluated using receiver-operating characteristic analysis: overall and solid portion sizes, fluid signal intensity (SI), degree of contrast-enhancement, and mean and minimum apparent diffusion coefficient (ADC) values of the solid portion. Two radiologists independently evaluated four MRI findings characteristic of SMBT, fluid SI on the T1-weighted image and SI of the solid portion on diffusion-weighted image. The diagnostic values of these findings and interobserver agreement were assessed.

RESULTS

For diagnosing SMBT, the mean ADC value of the solid portion showed the greatest area under the curve (0.860) (cut-off value: 1.31 × 10^-3 mm²/s, sensitivity: 1.00, specificity: 0.61). The T2-weighted image (T2WI) high SI solid portion was the most useful finding, with high specificity and interobserver agreement (sensitivity, 0.58; specificity, 0.95-0.96, kappa = 0.96), followed by T2WI low SI core (sensitivity, 0.48-0.63; specificity, 0.98, kappa = 0.68).

CONCLUSION

Mean ADC values of the solid portion, T2WI high SI solid portion, and T2WI low SI core were useful for differentiating SMBT from MT.

KEY POINTS

• SMBT is a newly categorised ovarian tumour often associated with endometriosis. • Differentiation of SMBT from endometriosis-related malignant ovarian tumour is clinically important. • Diagnostic performances of quantitative values and MRI findings were evaluated. • Mean ADC value of the solid portion was the most useful value. • "T2WI high SI solid portion" was the most useful MRI finding.

Endometrioid adenocarcinoma of the ovary: MRI findings with emphasis on diffusion-weighted imaging for the differentiation of ovarian tumors

BACKGROUND

Preoperative differentiation of ovarian malignant tumors still remains a challenge. Diffusion-weighted imaging (DWI) provides information about cellularity of the lesion and might facilitate discrimination between different malignant ovarian lesions.

PURPOSE

To evaluate magnetic resonance imaging (MRI) findings of endometrioid adenocarcinoma of the ovary and to determine the value of DWI in the differential diagnosis of malignant and benign adnexal tumors.

MATERIAL AND METHODS

The following MRI findings were reviewed in 162 patients (21 endometrioid adenocarcinoma, 103 other malignant tumors, 38 benign tumors): lesion size, morphological appearance, T2-weighted (T2W) signal intensity, T1-weighted (T1W) signal intensity, contrast-enhancement pattern, DWI signals with apparent diffusion coefficient (ADC) calculated for b = 800 s/mm(2) in solid tumor components.

RESULTS

The most common morphological appearance was predominantly cystic lesion, found in 90.3% of patients with endometriod adenocarcinoma. The solid parts were slightly hyperintense on T2W images in 19 patients with marked enhancement after contrast administration. No significant difference (P = 0.13) in conventional MRI features was found between endometrioid adenocarcinoma and other malignant ovarian tumors. Hyperintensity on DWI was more frequently observed in malignant tumors than in benign lesions (P < 0.001). ADC values were significantly lower in endometrioid adenocarcinoma than other malignant tumors (0.79 ± 0.21 vs. 0.90 ± 0.19; P = 0.04) and in all malignant lesions compared with benign tumors (0.88 ± 0.31 vs. 1.33 ± 0.17; P < 0.001).

CONCLUSION

DWI with ADC measurement could indicate the presence of endometrioid adenocarcinomas due to a slightly but significantly lower ADC values compared to other malignant ovarian lesions. Thus, DWI is beneficial and should be part of a standard protocol for the evaluation of indeterminate adnexal lesions.

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.

Huge ovarian endometrioma that grew after menopause: Case report

Endometriomas occur in women of reproductive age and are rare after menopause. A 56-year-old gravida 3 para 2 woman complained of abdominal fullness that had gradually worsened over approximately one year (i.e. 5 years postmenopause). Diagnostic imaging revealed a cystic lesion that extended to just below the diaphragm. An ovarian cystoma of low malignancy was suspected. The preoperative blood test indicated normal estradiol levels at 12.6 pg/mL. She underwent bilateral adnexectomy and total hysterectomy. The appendages on the affected (i.e. right) side weighed approximately 12 kg. An ovarian endometrioma with benign pathology was diagnosed. Postmenopausal endometrioma can occur even in patients with normal postmenopausal estradiol values who are not receiving exogenous hormones. These patients require careful follow-up.

Serum folate receptor alpha as a biomarker for ovarian cancer: Implications for diagnosis, prognosis and predicting its local tumor expression

Folate receptor alpha (FRA) is a GPI-anchored glycoprotein and encoded by the FOLR1 gene. High expression of FRA is observed in specific malignant tumors of epithelial origin, including ovarian cancer, but exhibits very limited normal tissue expression, making it as an attractive target for the ovarian cancer therapy. FRA is known to shed from the cell surface into the circulation which allows for its measurement in the serum of patients. Recently, methods to detect the soluble form of FRA have been developed and serum FRA (sFRA) is considered a highly promising biomarker for ovarian cancer. We prospectively investigated the levels of sFRA in patients clinically suspected of having malignant ovarian tumors. A total of 231 patients were enrolled in this study and analyzed for sFRA as well as tumor expression of FRA by immunohistochemistry. High sFRA was predominantly observed in epithelial ovarian cancer patients, but not in patients with benign or borderline gynecological disease or metastatic ovarian tumors from advanced colorectal cancers. Levels of sFRA were highly correlated to clinical stage, tumor grade and histological type and demonstrated superior accuracy for the detection of ovarian cancer than did serum CA125. High sFRA was significantly associated with shorter progression-free survival in both early and advanced ovarian cancer patients. Finally, tumor FRA expression status was strongly correlated with sFRA levels. Taken together, these data suggest that sFRA might be a useful noninvasive serum biomarkers for future clinical trials assessing FRA-targeted therapy.

A systematic review on endometriosis during pregnancy: diagnosis, misdiagnosis, complications and outcomes

BACKGROUND

Traditionally, pregnancy was considered to have a positive effect on endometriosis and its painful symptoms due not only to blockage of ovulation preventing bleeding of endometriotic tissue but also to different metabolic, hormonal, immune and angiogenesis changes related to pregnancy. However, a growing literature is emerging on the role of endometriosis in affecting the development of pregnancy and its outcomes and also on the impact of pregnancy on endometriosis. The present article aims to underline the difficulty in diagnosing endometriotic lesions during pregnancy and discuss the options for the treatment of decidualized endometriosis in relation to imaging and symptomatology; to describe all the possible acute complications of pregnancy caused by pre-existing endometriosis and evaluate potential treatments of these complications; to assess whether endometriosis affects pregnancy outcome and hypothesize mechanisms to explain the underlying relationships.

METHODS

This systematic review is based on material searched and obtained via Pubmed and Medline between January 1950 and March 2015. Peer-reviewed, English-language journal articles examining the impact of endometriosis on pregnancy and vice versa were included in this article.

RESULTS

Changes of the endometriotic lesions may occur during pregnancy caused by the modifications of the hormonal milieu, posing a clinical dilemma due to their atypical appearance. The management of these events is actually challenging as only few cases have been described and the review of available literature evidenced a lack of formal estimates of their incidence. Acute complications of endometriosis during pregnancy, such as spontaneous hemoperitoneum, bowel and ovarian complications, represent rare but life-threatening conditions that require, in most of the cases, surgical operations to be managed. Due to the unpredictability of these complications, no specific recommendation for additional interventions to the routinely monitoring of pregnancy of women with known history of endometriosis is advisable. Even if the results of the published studies are controversial, some evidence is suggestive of an association of endometriosis with spontaneous miscarriage, preterm birth and small for gestational age babies. A correlation of endometriosis with placenta previa (odds ratio from 1.67 to 15.1 according to various studies) has been demonstrated, possibly linked to the abnormal frequency and amplitude of uterine contractions observed in women affected. Finally, there is no evidence that prophylactic surgery would prevent the negative impact of endometriosis itself on pregnancy outcome.

CONCLUSIONS

Complications of endometriosis during pregnancy are rare and there is no evidence that the disease has a major detrimental effect on pregnancy outcome. Therefore, pregnant women with endometriosis can be reassured on the course of their pregnancies although the physicians should be aware of the potential increased risk of placenta previa. Current evidence does not support any modification of conventional monitoring of pregnancy in patients with endometriosis.

Primary ovarian endometrioid adenocarcinoma: magnetic resonance imaging findings including a preliminary observation on diffusion-weighted imaging

OBJECTIVE

This study aimed to investigate the magnetic resonance imaging (MRI) features of ovarian endometrioid adenocarcinoma (OEC) and to evaluate conventional MRI and diffusion-weighted imaging (DWI) for diagnosing OEC.

MATERIALS AND METHODS

Twenty patients with OEC proven by surgery and pathology underwent MRI. The MRI features of the tumors evaluated included laterality, shape, size, configuration, mural nodules, signal intensity, apparent diffusion coefficient (ADC) values, enhancement, peritoneal implants, ascites, and synchronous primary cancer (SPC) of the ovary and endometrium.

RESULTS

Unilateral ovarian masses were observed in 18 (90%) of the 20 patients with 22 OEC lesions, whereas the remaining 2 (10%) patients had bilateral masses. Oval, lobulated, and irregular shapes were observed in 13 (59%), 6 (27%), and 3 (14%) tumors, respectively. The maximum diameter of the tumors ranged from 3.7 to 22.5 cm, with a mean of 11.2 ± 5.1 cm. Fifteen (68%) masses were mainly cystic with mural nodules, 5 (23%) were mixed cystic-solid, and 2 (9%) were solid. The solid components of tumors showed isointensity (100%) on T1-weighted imaging (T1WI), heterogeneous hyperintensity on T2-weighted imaging (T2WI) (86%), and hyperintensity on DWI (82%), with a mean ADC value of (0.96 ± 0.20) × 10 mm/s. The cystic components showed isointensity or hyperintensity (85%) on T1WI, hyperintensity on T2WI (100%), and hypointensity on DWI (63%), with a mean ADC value of (2.27 ± 0.27) × 10 mm/s. Ten (50%) of the patients were SPC. The mean ADC values of the solid components were (0.85 ± 0.19) × 10 mm/s and (1.08 ± 0.15) × 10 mm/s in only-OEC and SPC, respectively, with a statistically significant difference (P = 0.012).

CONCLUSIONS

Ovarian endometrioid adenocarcinoma usually appears as a large, oval, or lobulated cystic mass with mural nodules. Cystic components show isointensity or hyperintensity on T1WI, solid components and hyperintensity on T2WI and DWI. Synchronous primary cancer of the ovary endometrium is another characteristic feature of OEC.

MRI for differentiating ovarian endometrioid adenocarcinoma from high-grade serous adenocarcinoma

PURPOSE

To investigate magnetic resonance imaging (MRI) features for differentiating ovarian endometrioid adenocarcinoma (OEC) from high-grade serous adenocarcinoma (HGSC).

MATERIALS AND METHODS

Twenty-three patients with 25 OECs and 93 patients with 139 HGSCs confirmed by surgery and pathology underwent conventional MRI and diffusion-weighted imaging (DWI). The MRI features of the tumors, including laterality, size, shape, configuration, signal intensity, ADC value of solid component, enhancement, ascites, synchronous primary cancer (SPC) of the ovary and endometrium, and clinical stage, were evaluated and compared between two groups.

RESULTS

The following characteristics were significantly more common for OECs than HGSCs: unilateral (91.3% vs 50.5%, P < 0.001), larger mass (80.0% vs 48.2%, P = 0.005), round or oval shape (64.0% vs 17.3%, P < 0.001), mainly cystic with mural nodules or papillary projections (72.0% vs 18.7%, P < 0.001), cystic component with homogeneous iso- or hyperintensity on T1WI (82.6% vs 4.3%, P < 0.001), moderate enhancement (52.0% vs 26.6%, P = 0.011), no or mild ascites (91.3% vs 57.0%, P = 0.002), and SPC (43.5% vs 4.3%, P < 0.001). The ADC value of the solid component was higher in OECs (0.979 ± 0.197 × 10(-3) mm(2)/s) than in HGSCs (0.820 ± 0.112 × 10(-3) mm(2)/s) (P = 0.002). When a mainly cystic mass with mural nodules or papillary projections was associated with any one of homogeneously iso- or hyperintense cystic component on TIWI, a relatively higher ADC value and SPC, the sensitivity, specificity, accuracy, and positive and negative predictive values for characterizing OEC were 87.0%, 93.5%, 92.2%, 76.9%, and 96.7%, respectively.

CONCLUSIONS

Conventional MRI combining DWI is helpful for differentiating OECs from HGSCs.

Predictive factors for the presence of malignant transformation of pelvic endometriosis

OBJECTIVES

To determine predictive factors for the presence of malignant transformation in ovarian endometriotic cysts.

STUDY DESIGN

This was an IRB approved, case control study analyzing patient data from 2004 to 2013. Pathology database records were searched to identify patients with benign endometrioma and ovarian carcinoma arising in the background of endometriosis. Inclusion criteria required each patient to have a preoperative diagnosis of adnexal mass and no other findings concerning for malignancy. Patient clinical records were queried for preoperative symptoms, serum CA125 levels and radiologic findings. Pathologic data were collected including histology, tumor grade and stage.

RESULTS

A total of 138 patients met inclusion criteria; 42 women with ovarian cancer arising in the background of endometriosis and 96 women with benign endometrioma. Women diagnosed with ovarian cancer were significantly older than women with endometriosis (53.6 vs. 39.2 years). There was no difference in presence of symptoms between the two groups. Women with malignant tumors were found to have significantly larger cysts (14 cm vs. 7.5 cm; p<0.0001) that were more often multilocular (45.7% vs. 12.2%; p<0.0001), and contained solid components (77.1% vs. 14.5%; p<0.0001). Among patients that were observed prior to surgery there was a significant difference in the change in size of the mass over time with 4.2 cm increase for cases vs. 1.0 cm increase for controls (p=0.02). Multiple logistic regression analysis indicated that for every 5 years increase in age there was an adjusted OR of 2.17 (p=0.003). An age of 49 years or greater had an 80.6% sensitivity (95% CI: 62.5-92.5%) and an 82.9% specificity (95% CI: 67.9-92.8%) for malignancy, and solid component on imaging had an adjusted OR of 23.7 (p<0.0001). Serum CA125 levels tended to be higher in patients with malignant tumors but did not reach statistical significance with a mean of 204.9 vs. 66.9 (p=0.1).

CONCLUSIONS

Significant predictors for malignant transformation of endometriosis include cyst characteristics and age. Women above the age of 49 with multilocular cysts and solid components are at high risk for malignant transformation of endometriosis. Serum CA125 level is not a significant predictor of malignant transformation.

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.

Pelvis: normal variants and benign findings in FDG-PET/CT imaging

With the widespread use of whole-body fluorodeoxyglucose (FDG)-PET/computed tomography as a diagnostic tool in patients with cancer, incidental findings are of increasing importance. This is particularly true within the pelvis, where several benign findings might present with increased FDG uptake. In addition, physiologic excretion of radiotracer by way of the urinary tract can complicate image analysis. This article reviews potential incidental benign findings in the pelvis that one should be aware of when interpreting FDG-PET/computed tomography scans.

Evaluation of primary adnexal masses by 3T MRI: categorization with conventional MR imaging and diffusion-weighted imaging

Background

To investigate the 3.0-Tesla (3 T) magnetic resonance imaging (MRI) characteristics of primary adnexal lesions for discriminating benign from malignant lesions.

Methods

One hundred thirty-nine patients with pathologically proven primary adnexal masses referred for 3 T MRI assessment preoperatively were included. Baseline characteristics, components, and conventional MRI and diffusion-weighted imaging (DWI-MRI) signals were recorded and compared.

Results

There were 22 ovarian cysts, 33 endometriomas, 43 benign tumors and 42 malignant tumors. When ovarian cyst and endometrioma were excluded, there were no significant differences in patients’ age between benign and malignant tumor (P = 0.235). There were no significant differences (P = 0.606) in the conventional MRI signals and significant difference (P = 0.008) in DWI-MRI signal between the non-malignant and malignant lesions. There was a significant difference (P = 0.000) in the apparent diffusion coefficient values (ADCs) between the non-malignant and malignant lesions.

Conclusions

3 T MRI categorized the characteristics of primary adnexal lesions. Conventional MRI signals were not useful for characterizing between benign and malignant lesions. DWI-MRI and ADCs were helpful for distinguishing malignant from benign ovarian lesions.

Thoracic endometriosis: a case report

Thoracic endometriosis is a rare form of extrapelvic endometriosis. These patients typically present with catamenial pneumothorax or hemoptysis. Adequate clinical history coupled with HRCT helps in early diagnosis and appropriate management of thoracic endometriosis.

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.