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

The diagnostic value of magnetic resonance imaging in differentiating benign and malignant pediatric ovarian tumors

BACKGROUND

The diagnostic workup of ovarian tumors in children and adolescents is challenging because preserving fertility, in addition to oncological safety, is of particular importance in this population. Therefore, a thorough preoperative assessment of ovarian tumors is required.

OBJECTIVE

To investigate the diagnostic value of MR imaging in differentiating benign from malignant ovarian tumors in children and adolescents.

MATERIALS AND METHODS

We conducted a retrospective study of all children and adolescents age <18 years who underwent MR imaging of ovarian tumors during 2014-2019 at a pediatric specialty center. Two radiologists reviewed all MR imaging. We used pathology reports to define the histological diagnosis.

RESULTS

We included 30 girls who underwent MR imaging for an ovarian tumor. Signs indicative for malignancy were tumors with a diameter ≥8 cm, with areas of contrast enhancement, irregular margins, extracapsular tumor growth, and ascites. All benign and malignant ovarian tumors were correctly identified by the radiologists.

CONCLUSION

The diagnostic utility of MR imaging in classifying ovarian tumors in children and adolescents as benign or malignant is promising and might aid in defining the indication for ovarian-sparing versus non-ovarian-sparing surgery. We recommend evaluating these tumors with MR imaging prior to deciding on surgical treatment.

Imaging Features of Neurofibromatosis Type 1 in the Abdomen and Pelvis

OBJECTIVE. Loss of the neurofibromatosis type 1 (NF1) tumor suppressor protein causes uninhibited activation of the RAS oncogene, which leads to tumorigenesis in patients with NF1. This case-based review discusses imaging manifestations of NF1 in the abdomen and pelvis, highlighting key genetic associations and management to elucidate features different from the general population. CONCLUSION. The spectrum of pathologic findings includes gastrointestinal tumors such as gastrointestinal stromal tumors, genitourinary lesions including urogenital neurofibromas, vascular entities such as renal artery stenosis, and less common associations like lymphoma.

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.

Adnexal masses characterized on 3 tesla magnetic resonance imaging - added value of diffusion techniques

Background

To assess different types of adnexal masses as identified by 3T MRI and to discuss the added value of diffusion techniques compared with conventional sequences.

Patients and methods

174 women age between 13 and 87 underwent an MRI examination of the pelvis for a period of three years. Patients were examined in two radiology departments – 135 of them on 3 Tesla MRI Siemens Verio and 39 on 3 Tesla MRI Philips Ingenia. At least one adnexal mass was diagnosed in 98 patients and they are subject to this study. Some of them were reviewed retrospectively. Data from patients’ history, physical examination and laboratory tests were reviewed as well.

Results

124 ovarian masses in 98 females’ group of average age 47.2 years were detected. Following the MRI criteria, 59.2% of the cases were considered benign, 30.6% malignant and 10.2% borderline. Out of all masses 58.1% were classified as cystic, 12.9% as solid and 29% as mixed. Оf histologically proven tumors 74.4% were benign and 25.6% were malignant. All of the malignant tumors had restricted diffusion. 64 out of all patients underwent contrast enhancement. (34 there were a subject of contraindications). 39 (61%) of the masses showed contrast enhancement.

Conclusions

Classifying adnexal masses is essential for the preoperative management of the patients. 3T MRI protocols, in particular diffusion techniques, increase significantly the accuracy of the diagnostic assessment.

Computer Tomography in the Diagnosis of Ovarian Cysts: The Role of Fluid Attenuation Values

Pathological analysis of ovarian cysts shows specific fluid characteristics that cannot be standardly evaluated on computer tomography (CT) examinations. This study aimed to assess the ovarian cysts’ fluid attenuation values on the native (Np), arterial (Ap), and venous (Vp) contrast phases of seventy patients with ovarian cysts who underwent CT examinations and were retrospectively included in this study. Patients were divided according to their final diagnosis into the benign group (n = 32) and malignant group (n = 38; of which 27 were primary and 11 were secondary lesions). Two radiologists measured the fluid attenuation values on each contrast phase, and the average values were used to discriminate between benign and malignant groups and primary tumors and metastases via univariate, multivariate, multiple regression, and receiver operating characteristics analyses. The Ap densities (p = 0.0002) were independently associated with malignant cysts. Based on the densities measured on all three phases, neoplastic lesions could be diagnosed with 89.47% sensitivity and 62.5% specificity. The Np densities (p = 0.0005) were able to identify metastases with 90.91% sensitivity and 70.37% specificity, while the combined densities of all three phases diagnosed secondary lesions with 72.73% sensitivity and 92.59% specificity. The ovarian cysts’ fluid densities could function as an adjuvant criterion to the classic CT evaluation of ovarian cysts.

Diagnostic value of [18F]FDG PET/MRI for staging in patients with ovarian cancer

Purpose

To evaluate the diagnostic potential of PET/MRI with 2-[¹⁸F]fluoro-2-deoxy-d-glucose ([¹⁸F]FDG) in ovarian cancer.

Materials and methods

Participants comprised 103 patients with suspected ovarian cancer underwent pretreatment [¹⁸F]FDG PET/MRI, contrast-enhanced CT (ceCT) and pelvic dynamic contrast-enhanced MRI (ceMRI). Diagnostic performance of [¹⁸F]FDG PET/MRI and ceMRI for assessing the characterization and the extent of the primary tumor (T stage) and [¹⁸F]FDG PET/MRI and ceCT for assessing nodal (N stage) and distant (M stage) metastases was evaluated by two experienced readers. Histopathological and follow-up imaging results were used as the gold standard. The McNemar test was employed for statistical analysis.

Results

Accuracy for the characterization of suspected ovarian cancer was significantly better for [¹⁸F]FDG PET/MRI (92.5%) [95% confidence interval (CI) 0.84–0.95] than for ceMRI (80.6%) (95% CI 0.72–0.83) (p < 0.05). Accuracy for T status was 96.4% (95% CI 0.96–0.96) and 92.9% (95% CI 0.93–0.93) for [¹⁸F]FDG PET/MRI and ceMRI/ceCT, respectively. Patient-based accuracies for N and M status were 100% (95% CI 0.88–1.00) and 100% (95% CI 0.88–1.00) for [¹⁸F]FDG PET/MRI and 85.2% (95% CI 0.76–0.85) and 30.8% (95% CI 0.19–0.31) for ceCT and M staging representing significant differences (p < 0.01). Lesion-based sensitivity, specificity and accuracy for N status were 78.6% (95% CI 0.57–0.91), 95.7% (95% CI 0.93–0.97) and 93.9% (95% CI 0.89–0.97) for [¹⁸F]FDG PET/MRI and 42.9% (95% CI 0.24–0.58), 96.6% (95% CI 0.94–0.98) and 90.8% (95% CI 0.87–0.94) for ceCT.

Conclusions

[¹⁸F]FDG PET/MRI offers better sensitivity and specificity for the characterization and M staging than ceMRI and ceCT, and diagnostic value for T and N staging equivalent to ceMRI and ceCT, suggesting that [¹⁸F]FDG PET/MRI might represent a useful diagnostic alternative to conventional imaging modalities in ovarian cancer.

Differentiation of borderline tumors from type I ovarian epithelial cancers on CT and MR imaging

PURPOSE

To investigate the value of CT and MR imaging features in differentiating borderline ovarian tumor (BOT) from type I ovarian epithelial cancer (OEC), which could be significant for suitable clinical treatment and assessment of the prognosis of the patient.

METHODS

Thirty-three patients with BOTs and 35 patients with type I OECs proven by pathology were retrospectively evaluated. The clinico-pathological information (age, premenopausal status, CA-125, and Ki-67) and imaging characteristics were compared between two groups of ovarian tumors. The diagnostic performance of the imaging features was evaluated using receiver operating characteristic analysis. The best predictor variables for type I EOCs were recognized via multivariate analyses.

RESULTS

BOTs are more likely to involve younger patients and frequently show lower CA-125 values and lower proliferation indices (Ki-67 < 15%) than type I OECs. Compared with type I OECs, BOTs were more often purely cystic (15/33, 45.45% vs. 1/35, 2.86%; p < 0.001) and displayed less frequent mural nodules (16/33, 48.48% vs. 28/35, 80.00%; p = 0.007), less frequently unclear margin (3/33, 9.09% vs. 11/35, 31.43%; p = 0.023), smaller solid portion (0.56 ± 2.66 vs. 4.51 ± 3.88; p < 0.001), and thinner walls (0.3 ± 0.17 vs. 0.55 ± 0.24; p < 0.001). The maximum wall thickness presented the largest area under the curve (AUC, 0.848). Multivariate analysis revealed that the solid portion size (OR 10.822, p = 0.002) and maximum wall thickness (OR 9.130, p = 0.001) were independent indicators for the differential diagnosis between the two groups of lesions.

CONCLUSION

The solid portion size and maximum wall thickness significantly influenced the classification of the two groups of ovarian tumors.

Terahertz Imaging and Spectroscopy in Cancer Diagnostics: A Technical Review

Terahertz (THz) waves are electromagnetic waves with frequency in the range from 0.1 to 10 THz. THz waves have great potential in the biomedical field, especially in cancer diagnosis, because they exhibit low ionization energy and can be used to discern most biomolecules based on their spectral fingerprints. In this paper, we review the recent progress in two applications of THz waves in cancer diagnosis: imaging and spectroscopy. THz imaging is expected to help researchers and doctors attain a direct intuitive understanding of a cancerous area. THz spectroscopy is an efficient tool for component analysis of tissue samples to identify cancer biomarkers. Additionally, the advantages and disadvantages of the developed technologies for cancer diagnosis are discussed. Furthermore, auxiliary techniques that have been used to enhance the spectral signal-to-noise ratio (SNR) are also reviewed.

Evaluation of Ovarian Tumors with Multidetector Computed Tomography and Tumor Markers: Differentiation of Stage I Serous Borderline Tumors and Stage I Serous Malignant Tumors Presenting as Solid-Cystic Mass

Background

The aim of this study was to determine multidetector computed tomography (MDCT) features and tumor markers for differentiating stage I serous borderline ovarian tumors (SBOTs) from stage I serous malignant ovarian tumors (SMOTs).

Material/Methods

In total, 48 patients with stage I SBOTs and 54 patients with stage I SMOTs who underwent MDCT and tumor markers analysis were analyzed. MDCT features included location, shape, margins, texture, papillary projections, vascular abnormalities, size, and attenuation value. Tumor markers included serum cancer antigen 125 (CA125), carbohydrate antigen 19-9 (CA19-9), carcinoembryonic antigen (CEA), and human epididymis protein 4 (HE4). Parameters of clinical characteristic, MDCT features, and tumor markers were compared using a chi-square test and Mann-Whitney U tests. A binary logistic regression analysis was performed to detect predictors for SMOTs. A receiver operating characteristic (ROC) curve analysis was used to assess the potential diagnostic value of the quantitative parameters. Kappa and intraclass correlation coefficients were used to evaluate interobserver reproducibility for MDCT features.

Results

Median ages between patients with SBOTs and SMOTs were significantly different. Compared with SBOTs, vascular abnormalities were significantly more common in SMOTs. CA125, HE4, the maximum thickness of the wall, the maximum thickness of the septa, and the maximum diameter of the solid portions were significantly higher in patients with SMOTs. A binary logistic regression analysis revealed that age, vascular abnormalities, and the maximum diameter of the solid portion were independent factors of SMOTs. ROC analysis was used to assess the potential diagnostic value for predicting SMOTs. Moderate or good interobserver reproducibility for MDCT features were identified.

Conclusions

Age, vascular abnormalities, and the maximum diameter of the solid portion were independent factors for differentiating SBOTs from SMOTs. The combined analysis of age, vascular abnormalities, and the maximum diameter of the solid portion may allow better differentiation between SBOTs and SMOTs.

Altered Organelle Calcium Transport in Ovarian Physiology and Cancer

Calcium levels have a huge impact on the physiology of the female reproductive system, in particular, of the ovaries. Cytosolic calcium levels are influenced by regulatory proteins (i.e., ion channels and pumps) localized in the plasmalemma and/or in the endomembranes of membrane-bound organelles. Imbalances between plasma membrane and organelle-based mechanisms for calcium regulation in different ovarian cell subtypes are contributing to ovarian pathologies, including ovarian cancer. In this review, we focused our attention on altered calcium transport and its role as a contributor to tumor progression in ovarian cancer. The most important proteins described as contributing to ovarian cancer progression are inositol trisphosphate receptors, ryanodine receptors, transient receptor potential channels, calcium ATPases, hormone receptors, G-protein-coupled receptors, and/or mitochondrial calcium uniporters. The involvement of mitochondrial and/or endoplasmic reticulum calcium imbalance in the development of resistance to chemotherapeutic drugs in ovarian cancer is also discussed, since Ca²⁺ channels and/or pumps are nowadays regarded as potential therapeutic targets and are even correlated with prognosis.

Novel classification of ovarian metastases originating from colorectal cancer by radiological imaging and macroscopic appearance

BACKGROUND

Diagnosis of secondary ovarian tumors originating from colorectal cancer has previously been based upon history of malignancy and radiological findings of bilateral masses with a "stained glass appearance." The purpose of this study was to perform a detailed investigation of the radiological and macroscopic features of ovarian metastases originating from colorectal cancer, which remain to be fully characterized.

METHODS

Study participants were 48 consecutive patients with ovarian metastases from colorectal cancer who underwent resection of ovarian tumors at the National Cancer Center Hospital between August 1998 and January 2019. Ovarian tumors were classified into subgroups using computed tomography (CT), magnetic resonance imaging (MRI), and macroscopic appearance.

RESULTS

CT/MRI findings and macroscopic appearance were classified into the following four types: type 1 (oval, homogeneous-solid) (n = 5); type 2 (heterogeneous-solid, small in size with multinodular surface) (n = 3); type 3 (solid-cystic, predominantly solid) (n = 18); and type 4 (cystic-solid, multilocular with solid components) (n = 22). Type 1 mimics Krukenberg tumors, type 2 mimics ovarian metastases from breast cancer, type 3 mimics primary ovarian endometrioid cancer, and type 4 mimics primary ovarian mucinous cancer, with a "stained glass appearance". Twenty-eight (58%) patients had bilateral metastases. Eleven patients (23%) underwent hysterectomy and/or pelvic lymph node dissection in addition to ovarian resection.

CONCLUSION

We introduced a novel classification system for ovarian metastases originating from colorectal cancer, which may be beneficial for assessing ovarian metastases from colorectal cancer and avoiding unnecessary surgery due to misdiagnosis of primary ovarian tumors.

A Nomogram Combined Radiomic and Semantic Features as Imaging Biomarker for Classification of Ovarian Cystadenomas

Objective: To construct and validate a combined Nomogram model based on radiomic and semantic features to preoperatively classify serous and mucinous pathological types in patients with ovarian cystadenoma.

Methods: A total of 103 patients with pathology-confirmed ovarian cystadenoma who underwent CT examination were collected from two institutions. All cases divided into training cohort (N = 73) and external validation cohort (N = 30). The CT semantic features were identified by two abdominal radiologists. The preprocessed initial CT images were used for CT radiomic features extraction. The LASSO regression were applied to identify optimal radiomic features and construct the Radscore. A Nomogram model was constructed combining the Radscore and the optimal semantic feature. The model performance was evaluated by ROC analysis, calibration curve and decision curve analysis (DCA).

Result: Five optimal features were ultimately selected and contributed to the Radscore construction. Unilocular/multilocular identification was significant difference from semantic features. The Nomogram model showed a better performance in both training cohort (AUC = 0.94, 95%CI 0.86–0.98) and external validation cohort (AUC = 0.92, 95%CI 0.76–0.98). The calibration curve and DCA analysis indicated a better accuracy of the Nomogram model for classification than either Radscore or the loculus alone.

Conclusion: The Nomogram model combined radiomic and semantic features could be used as imaging biomarker for classification of serous and mucinous types of ovarian cystadenomas.

Bimodal magnetic resonance and optical imaging of extracellular matrix remodelling by orthotopic ovarian tumours

BACKGROUND

The extracellular matrix modulates the development of ovarian tumours. Currently, evaluation of the extracellular matrix in the ovary is limited to histological methods. Both magnetic resonance imaging (MRI) and two-photon microscopy (2PM) enable dynamic visualisation and quantification of fibrosis by endogenous contrast mechanisms: magnetisation transfer (MT) MRI and second-harmonic generation (SHG) 2PM, respectively.

METHODS

Here, we applied the MT-MRI protocol for longitudinal imaging of the stroma in orthotopic human ovarian cancer ES-2 xenograft model in CD1 athymic nude mice, and for orthotopically implanted ovarian PDX using a MR-compatible imaging window chamber implanted into NSG mice.

RESULTS

We observed differences between ECM deposition in ovarian and skin lesions, and heterogeneous collagen distribution in ES-2 lesions. An MR-compatible imaging window chamber enabled visual matching between T2 MRI maps of orthotopically implanted PDX grafts and anatomical images of their microenvironment acquired with a stereomicroscope and SHG-2PM intravital microscopy of the collagen. Bimodal MRI/2PM imaging allowed us to quantify the fibrosis within the same compartments, and demonstrated the consistent results across the modalities.

CONCLUSIONS

This work demonstrates a novel approach for measuring the stromal biomarkers in orthotopic ovarian tumours in mice, on both macroscopic and microscopic levels.

Ovarian Diffuse Large B-cell Lymphoma Initially Suspected Dysgerminoma Managed by Laparoscopic Staging Surgery

Ovarian diffuse large B-cell lymphoma (DLBCL) is rare. DLBCL is a complex type of lymphoma. The ovarian DLBCL usually harbor a favorable prognosis. We report a case of ovarian DLBCL that presented as an ovarian mass with lower abdominal pain and was managed using laparoscopic staging surgery. A 29-year-old female (gravida 2, para 0, abortion 2) with a history of polycystic ovarian syndrome with irregular medication control visited our clinic due to lower abdominal pain. Transvaginal ultrasound revealed a heterogeneous, septated mass over the left adnexa with a diameter of approximately 6 cm × 8 cm. The tumor marker CA 19-9 was elevated (65.77 IU/mL); CA125 and carcinoembryonic antigen were not elevated. Laparoscopic surgery with left salpingo-oophorectomy was first performed. Frozen section indicated dysgerminoma. Then, we continued staging surgery through bilateral pelvic lymph node dissection, para-aortic lymph node dissection, omentectomy, right ovary and peritoneum biopsy, and washing cytology. Ovarian tumor and para-aortic lymph nodes were positive for lymphoma. The tumor cells were positive staining for CD20, CD5, ki67, BCL-6, and MUM-1, which was associated with DLBCL. The patient was then consulted for oocyte preservation and referred to hematology for further chemotherapy. In conclusion, an ovarian lymphoma is a rare event. The presence of an enlarged ovarian tumor should raise the suspicion of ovarian lymphoma. To differentiate ovarian lymphoma from dysgerminoma, immunohistochemistry is useful. Fertility preservation should be considered before chemotherapy. Ovarian tissue or oocyte preservation or gonadotropin-releasing hormone agonist injection before chemotherapy can be performed for fertility preservation.

Mucinous Neoplasms of the Ovary: Radiologic-Pathologic Correlation

Mucinous neoplasms of the ovary account for 10%-15% of ovarian neoplasms. They may be benign, borderline, or malignant. The large majority are benign or borderline, accounting for 80% and 16%-17%, respectively. Mucinous neoplasms of the ovary most commonly affect women in their 20s to 40s. The clinical manifestation is nonspecific, but most mucinous ovarian neoplasms manifest as large unilateral pelvic masses. At gross pathologic analysis, mucinous ovarian neoplasms appear as large multiloculated cystic masses. The contents of the cyst loculi vary on the basis of differences in internal mucin content. At histologic analysis, mucinous ovarian neoplasms are composed of multiple cysts lined by mucinous epithelium, often resembling gastrointestinal-type epithelium. Imaging evaluation most commonly includes US and/or MRI. The imaging findings parallel the gross pathologic features and include a large, unilateral, multiloculated cystic mass. The cyst loculi vary in echogenicity, attenuation, and signal intensity depending on the mucin content. Mucinous neoplasms of the ovary are staged surgically using the FIGO (International Federation of Gynecology and Obstetrics) staging system. Primary treatment is surgical, with adjuvant chemotherapy considered in the uncommon case of mucinous carcinoma with extraovarian disease. Since most mucinous ovarian neoplasms are benign or borderline, the overall prognosis is excellent.

Epithelial ovarian cancer: a review of preoperative imaging features indicating suboptimal surgery

Epithelial ovarian cancer has been traditionally treated with cytoreductive surgery and chemotherapy. Optimal surgery is the key to improving the prognosis, and, thus, preoperative imaging should be carefully assessed to determine if the involvement of gastrointestinal, vascular, or thoracic surgeons is necessary to achieve this. Consequently, gynecologists should be able to recognize which imaging features suggest optimal or suboptimal resection. The aim of this review was to present the preoperative imaging features indicating suboptimal resection of epithelial ovarian cancer.

Radiographic Features of a Benign Mixed Brenner Tumor and Mucinous Cystadenoma: A Rarely Identified Ovarian Neoplasm on Imaging

Imaging features of benign mixed Brenner tumor and mucinous cystadenomas are rarely reported. This report aims to describe the case of a benign mixed Brenner tumor and mucinous cystadenoma with a dominant Brenner tumor component and to review the typical imaging features of this ovarian neoplasm.

Multimodality imaging and genomics of granulosa cell tumors

OBJECTIVE

The purpose of this article is to review the imaging findings and genomics of granulosa cell tumors (GCTs) in order to aid in diagnosis and management of GCTs. GCTs are the most common type of sex cord-stromal tumors of the ovary. They are usually diagnosed initially with ultrasound and are subsequently further characterized with CT and MRI. PET/CT is often ordered as well to measure the extent of disease and for follow-up, but its usefulness is in question as some GCTs lack FDG avidity. There is significant variability in imaging phenotypes of GCTs, ranging from mostly cystic to almost solid. More resources have recently been dedicated to understanding the genetics and molecular mechanisms of GCT development. Current research shows that the main cause of GCT carcinogenesis is the FOXL2 mutation, but there are several other noteworthy mutations that contribute to the pathogenesis of this disease. Certain mutations, like GATA4, are known to be associated with more aggressive disease and higher rates of recurrence.

CONCLUSION

Using this information, imaging protocols can be altered depending on the genotype of the tumor. Further understanding of the genetic alterations that underpin the development of GCTs is indicated as genotypic knowledge could be used to guide optimal imaging and management strategies.

Mature cystic ovarian teratoma without intracystic fat: Case report with the "fat within the wall" sign

Mature cystic teratoma is the most common ovarian neoplasm among young females. Diagnosed through radiological imaging as it exhibits typical radiological features; typically, fat. However, complete cystic teratoma without visible fat is a very rare and challenging diagnosis. It is difficult to distinguish it from malignant neoplasm, due to the presence of enhancing components, for example, Rokitansky nodule and the presence of diffusion restriction from keratinized products. We present a case of an incidental mature cystic teratoma without visible intracystic fat, where the correct diagnosis based on imaging was failed. Mature cystic teratoma was then confirmed upon histologic examination.

Imaging in pediatric ovarian tumors

The spectrum of ovarian tumors in the pediatric population differs significantly from that in adults. Germ cell tumors are the predominant class of ovarian tumors in children, whereas epithelial tumors are the most common in adults. Ultrasonography is the modality of choice for the initial evaluation of pediatric ovarian tumors. Determining the diagnosis based on imaging may prove difficult, and combining the imaging findings with the clinical scenario is very helpful in reaching a differential diagnosis during clinical practice. We will discuss the spectrum of ovarian neoplasms in the pediatric population and describe their clinical, pathologic, and imaging characteristics. A few unique entities related to ovarian tumors, such as growing teratoma syndrome, anti-N-methyl-D-aspartate receptor encephalitis, and hereditary ovarian tumor syndromes, are also discussed. In addition, we will review several entities that may mimic ovarian neoplasms as well as their distinct imaging features.

Extrahepatic Fat-Containing Lesions of the Abdomen and Pelvis: An Organ-Based Approach to Differential Diagnoses

The presence of intralesional fat provides an invaluable tool for narrowing the differential diagnosis for both benign and malignant neoplasms of the abdomen and pelvis. The ability to characterize intralesional fat is further expanded by the ability of magnetic resonance imaging to detect small quantities (intravoxel) of fat. While the presence of intralesional fat can help to provide a relatively narrow set of diagnostic possibilities, depending on the type of fat (macroscopic vs intravoxel) that is present and the organ of origin, radiologists must be aware of uncommon mimickers of pathology, both benign and malignant.

Emergent MRI for acute abdominal pain in pregnancy-review of common pathology and imaging appearance

Acute abdominal pain in pregnancy remains a clinically challenging presentation, often requiring imaging. The threat of morbidity and mortality to both mother and fetus necessitates quick and accurate imaging diagnosis, often via ultrasound. However, many of the common causes of acute abdominal pain are not readily diagnosed with sonography, and magnetic resonance imaging (MRI) is increasingly favored in this setting. The purpose of this review is to familiarize the reader with common pathologies which may be encountered in pregnant females presenting with acute abdominal pain requiring emergent MRI.

Adnexal incidentalomas on multidetector CT: how to manage and characterise

Although CT is not considered the examination of choice for the detection and characterisation of adnexal diseases, adnexal masses may be incidentally detected during CT examination performed for other clinical indications. Most adnexal incidentalomas are benign, and therefore may not require further investigation, follow-up or intervention; however, few of them may prove malignant. Multidetector CT has improved the diagnostic performance of the technique in the detection and differentiation of adnexal mass lesions. Radiologists should be able to recognise the normal CT appearance of the ovaries and the CT characteristics of various adnexal incidentalomas. This may obviate unnecessary imaging evaluation and allow optimal treatment planning. Regarding the management of adnexal lesions incidentally found on CT, recommendations based on the collective experience of the members of the American College of Radiology Incidental Findings Committee II have recently been presented.

MR imaging in discriminating between benign and malignant paediatric ovarian masses: a systematic review

OBJECTIVES

The use of magnetic resonance (MR) imaging in differentiation between benign and malignant adnexal masses in children and adolescents might be of great value in the diagnostic workup of sonographically indeterminate masses, since preserving fertility is of particular importance in this population. This systematic review evaluates the diagnostic value of MR imaging in children with an ovarian mass.

METHODS

The review was made according to the PRISMA Statement. PubMed and EMBASE were systematically searched for studies on the use of MR imaging in differential diagnosis of ovarian masses in both adult women and children from 2008 to 2018.

RESULTS

Sixteen paediatric and 18 adult studies were included. In the included studies, MR imaging has shown good diagnostic performance in differentiating between benign and malignant ovarian masses. MR imaging techniques including diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) imaging seem to further improve the diagnostic performance.

CONCLUSION

The addition of DWI with apparent diffusion coefficient (ADC) values measured in enhancing components of solid lesions and DCE imaging may further increase the good diagnostic performance of MR imaging in the pre-operative differentiation between benign and malignant ovarian masses by increasing specificity. Prospective age-specific studies are needed to confirm the high diagnostic performance of MR imaging in children and adolescents with a sonographically indeterminate ovarian mass.

KEY POINTS

• MR imaging, based on several morphological features, is of good diagnostic performance in differentiating between benign and malignant ovarian masses. Sensitivity and specificity varied between 84.8 to 100% and 20.0 to 98.4%, respectively. • MR imaging techniques like diffusion-weighted imaging (DWI) and dynamic contrast-enhanced (DCE) imaging seem to improve the diagnostic performance. • Specific studies in children and adolescents with ovarian masses are required to confirm the suggested increased diagnostic performance of DWI and DCE in this population.

Imaging findings for mucinous tumors of the abdomen and pelvis

This article aims to describe the imaging findings for mucinous tumors of the abdomen and pelvis, which have a similar appearance on imaging tests regardless of the organ in which they develop. Due to the high water content of mucus, the appearance of these tumors is generally similar to that of water on ultrasonography, computed tomography, and magnetic resonance imaging. Another common feature of mucin-producing tumors is that calcifications are often present. The rupture of these lesions and accumulation of mucinous material in the peritoneal cavity gives rise to pseudomyxoma peritonei. It is important to identify mucinous tumors because they have a different prognosis and clinical course than non-mucinous tumors and require different management. Depending on their anatomic location and their imaging characteristics, the treatment approach varies from follow-up to radical surgery together with chemotherapy or radiotherapy or both.

Intra-peritoneal mature benign cystic teratoma deposits: an unusual complication from previous surgical resection of an ovarian mature benign cystic teratoma

In this case, we describe multiple unusual intra-peritoneal lesions containing fat, soft tissue and calcification. These were found radiologically and histologically to be in keeping with mature benign cystic teratoma intra-peritoneal deposits, also described as dermoid cysts. These were presumed to be due to seeding from surgical resection of ovarian mature benign cystic teratoma 5 years previously. This surgical complication has not been well documented thus far in the literature.

Calcified mucinous adenocarcinoma of the stomach metastatic to the iris: a case report

Background

Gastric cancer has a wide spectrum of clinical features, imaging manifestations, and pathology. Punctate calcifications in gastric cancer are infrequent but are usually found in mucinous adenocarcinoma. However, there have only been a few autopsy case reports describing the correlation between the radiology and pathology findings of calcified mucinous adenocarcinoma of the stomach. We present an autopsy case of mucinous gastric adenocarcinoma with iris metastases as the initial symptom.

Case presentation

A 74-year-old Japanese woman presented with blurred vision. Her treating ophthalmologist diagnosed acute iritis with secondary glaucoma. The histopathological and immunohistochemical features of a trabeculectomy specimen favored metastatic carcinoma, most likely of gastrointestinal tract origin. Esophagogastroduodenoscopy revealed multiple irregularly shaped ulcerative lesions, multiple erosions, and thickened folds in the corpus of her stomach. Histologic examination of a gastric tissue specimen obtained by endoscopic biopsy revealed poorly differentiated carcinoma with signet ring cell features. Computed tomography revealed a tumor with multiple punctate calcifications in the thickened gastric wall with diffuse low attenuation and multiple lymph node metastases, including the para-aortic lymph nodes, and peritoneal dissemination. She was diagnosed with stage IV gastric cancer (T4N3M1) and underwent seven cycles of 5-weekly TS-1, a novel oral fluoropyrimidine derivative, plus cisplatin therapy. Serial follow-up computed tomography revealed successive increases in the gastric wall calcifications. Her disease stabilized, but she died of aspiration pneumonia 8 months after the first visit. Autopsy tissue specimens had miliary, punctate calcifications present in abundant extracellular mucin pools in the submucosa, corresponding to the thickened low-attenuating middle layer on computed tomography. The final diagnosis was mucinous gastric adenocarcinoma because mucinous adenocarcinoma is diagnosed when more than half of the tumor area contains extracellular mucin pools.

Conclusions

We report the pathology and computed tomography imaging characteristics of a case of calcified mucinous adenocarcinoma of the stomach metastatic to the iris, including findings at autopsy. Metastatic carcinomas in the iris originating in the stomach are exceedingly rare. Multiple punctate calcifications were present in pools of extracellular mucin, a diagnostic clue for mucinous adenocarcinoma. Possible mechanisms underlying scattered punctuate calcifications in gastric mucinous adenocarcinoma warrant further investigation.

ACR Appropriateness Criteria® Staging and Follow-Up of Ovarian Cancer

In the management of epithelial ovarian cancers, imaging is used for cancer detection and staging, both before and after initial treatment. The decision of whether to pursue initial cytoreductive surgery for ovarian cancer depends in part on accurate staging. Contrast-enhanced CT of the abdomen and pelvis (and chest where indicated) is the current imaging modality of choice for the initial staging evaluation of ovarian cancer. Fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT and MRI may be appropriate for problem-solving purposes, particularly when lesions are present on CT but considered indeterminate. In patients who achieve remission, clinical suspicion for relapse after treatment prompts imaging evaluation for recurrence. Contrast-enhanced CT is the modality of choice to assess the extent of recurrent disease, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT is also usually appropriate, as small metastatic foci may be identified. If imaging or clinical examination confirms a recurrence, the extent of disease and timing of disease recurrence then determines the choice of treatments, including surgery, chemotherapy, and radiation therapy. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Magnetic resonance imaging findings for discriminating clear cell carcinoma and endometrioid carcinoma of the ovary

Background

Common cancerous histological types associated with endometriosis are clear cell carcinoma (CCC) and endometrioid carcinoma (EC). CCC is regarded as an aggressive, chemoresistant histological subtype. Magnetic resonance imaging (MRI) offers some potential advantages to diagnose ovarian tumors compared with ultrasonography or computed tomography. This study aimed to identify MRI features that can be used to differentiate between CCC and EC.

Methods

We searched medical records of patients with ovarian cancers who underwent surgical treatment at Nara Medical University Hospital between January 2008 and September 2018; we identified 98 patients with CCC or EC who had undergone preoperative MRI. Contrasted MRI scans were performed less than 2 months before surgery. Patients were excluded from the study if they had no pathology, other pathological subtype of epithelial ovarian cancer, and/or salvage treatment for recurrence and metastatic ovarian cancer at the time of study initiation. Clinically relevant variables that were statistically significant by univariate analysis were selected for subsequent multivariate regression analysis to identify independent factors to distinguish CCC from EC.

Results

MRI of CCC and EC showed a large cystic heterogeneous mixed mass with mural nodules protruding into the cystic space. Univariate logistic regression analysis revealed that the growth pattern (broad-based nodular structures [multifocal/concentric sign] or polypoid structures [focal/eccentric sign]), surface irregularity (a smooth/regular surface or a rough/irregular/lobulated surface), “Width” of mural nodule, “Height-to-Width” ratio (HWR), and presence of preoperative ascites were factors that significantly differed between CCC and EC. In the multivariate logistic regression analysis, the growth pattern of the mural nodule (odds ratio [OR] = 0.69, 95% confidence interval [CI]: 0.013–0.273, p = 0.0004) and the HWR (OR = 3.71, 95% CI: 1.128–13.438, p = 0.036) were independent predictors to distinguish CCC from EC.

Conclusions

In conclusion, MRI data showed that the growth pattern of mural nodules and the HWR were independent factors that could allow differentiation between CCC and EC. This finding may be helpful to predict patient prognosis before operation.

Inflammatory peritonitis secondary to rupture of borderline mucinous ovarian tumor

We present the case of a woman with a history of untreated borderline ovarian tumor. She went to the emergency department with abdominal pain and vomiting. In this context, the first diagnostic possibilities to rule out were tumor progression and/or tumor complication. Inflammatory peritonitis secondary to a ruptured ovarian tumor is a complication that has not been widely discussed. It is a surgical emergency. The differential diagnosis should be made with peritoneal carcinomatosis. The main radiological finding that should make us to suspect this entity is the reduction of tumor’s size in an untreated ovarian mass.

Low-grade epithelial ovarian cancer: what a radiologist should know

Ovarian cancer accounts for the death of over 100,000 females every year and is the most lethal gynecological malignancy. Low-grade serous ovarian carcinoma (LGSOC) and high-grade serous ovarian carcinoma (HGSOC) have been found to represent two distinct entities based on their molecular differences, clinical course, and response to chemotherapy. Currently, all ovarian cancers are staged according to the revised staging system of the International Federation of Gynecology and Obstetrics (FIGO). Imaging plays an integral role in the diagnosis, staging, and follow-up of ovarian cancers. This review will be based on the two-tier grading system of epithelial ovarian cancers, with the main emphasis on serous ovarian cancer, and the role of imaging to characterize low-grade vs high-grade tumors and monitor disease recurrence during follow-up.

A case report and a literature review of primary retroperitoneal mucinous cystadenoma: the importance of imaging in diagnosis and management

Primary retroperitoneal mucinous cystadenoma (PRMC) is an extremely rare tumor: its histogenesis and its biological behavior remain speculative. Since most retroperitoneal tumors are malignant, a preoperative diagnosis of benignity is essential and it can be reached through imaging examinations, allowing a conservative management approach. We describe the case of a 52-year-old woman with abdominal pain and a palpable mass. Computed tomography of the abdomen revealed a retroperitoneal cystic mass, which was resected successfully through laparoscopy and diagnosed as PRMC. Although there are no pathognomonic, clinical or radiological findings for PRMC, it should be included in the list of differential diagnoses and its imaging criteria of benignity should always be sought, with the aim to exclude malignant tumors.

Squamous cell carcinoma arising from mature cystic teratoma of the ovary: A challenging question for gynecologic oncologists

Mature cystic teratomas of the ovary have an incidence of 1.2-14.2 cases per 100.000 people per year. Malignant transformation occurs in approximately 2% of the cases, and usually consists of squamous cell carcinoma. The preoperative detection is difficult and the diagnostic accuracy of ultrasound, magnetic resonance imaging, and computed tomography is debated. The diagnosis is frequently made in the operating room or on final histological examination. Standard treatment consists of bilateral salpingo-oophorectomy, total hysterectomy and comprehensive surgical staging in early disease and optimal cytoreductive surgery in advanced disease. Paclitaxel/carboplatin- based chemotherapy is the most used adjuvant treatment, whereas more aggressive regimens can be adopted in patients with high tumor burden or recurrent disease. The efficacy of radiotherapy is still unproven. The prognosis is poor when the tumor has spread beyond the ovary. There are few information to provide commonly accepted guidelines for this malignancy.

The value of MRI for differentiating benign from malignant sex cord-stromal tumors of the ovary: emphasis on diffusion-weighted MR imaging

Background

To investigate MRI for differentiating benign from malignant sex cord-stromal tumors of the ovary (SCSTs) emphasizing on the value of diffusion-weighted (DW) magnetic resonance (MR) imaging.

Methods

This retrospective study included 29 benign SCSTs in 28 patients and 13 malignant SCSTs in 13 patients. DW imaging as well as conventional MR imaging was performed. Signal intensity on DW imaging was assessed and apparent diffusion coefficient (ADC) value was measured. In addition, T2 signal intensity and contrast enhancement pattern were also assessed and compared between benign and malignant SCSTs.

Results

Both of the T2 hypointensity and mild enhancement were specific to benign SCSTs. The majority of malignant SCSTs showed high signal intensity on DW imaging, whereas most benign SCSTs showed low or moderate signal intensity (p = 0.000). Fibromas were the tumors with the lowest observed ADC value (0.470 × 10^− 3 mm²/s). Sclerosing stromal tumors were the tumors with the highest observed ADC value (2.291 × 10^− 3 mm²/s). ADC value of solid component was significantly lower in malignant SCSTs (0.825 ± 0.129 × 10^− 3 mm²/s) than in benign SCSTs (1.343 ± 0.528 × 10^− 3 mm²/s) when fibromas were excluded (p = 0.024). T2, DCE and DW imaging has a limited value on the differential diagnosis of the benign and malignant SCSTs with an accuracy of 69.0%,71.4% and 78.1% respectively. Combination of T2, DCE and DW imaging permitted the distinction with an accuracy of 88.0%.

Conclusions

It is more helpful for distinction of the benign and malignant SCSTs by combining of T2, DCE and DW imaging than using each of the three sequences independently.

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.

Computed tomography imaging features of benign ovarian Brenner tumors

The present study aimed to describe the computed tomography (CT) imaging features of ovarian Brenner tumor for diagnostic accuracy and disease understanding. The CT imaging features of 9 cases of ovarian Brenner tumor confirmed by surgery and pathology were retrospectively analyzed and compared. Of the 9 cases of ovarian Brenner tumor, 3 were right located and 6 were left located with clear borders; 7 with round or oval shapes, while 2 were with irregular and lobulated morphology; 5 solid lesions presented with multiple scattered calcification shadows inside with moderate enhancement, while 3 cystic lesions were presented with mixed solid and cystic composition, and significant enhancement was identified in the solid component, but not in the cystic component. Furthermore, papillary projections inside and mild nodular enhancement were observed in one case of cystic lesion. The pathological analysis demonstrated that an epithelium nest composed the tumors with urothelial like cells and fibrous matrix. Of the 9 cases, 5 epithelial nests exhibited adeno-like cystic lumen without cell mitosis phase. All cases were diagnosed with benign ovarian Brenner tumor. Specific CT imaging features of ovarian Brenner tumor can be identified and pathological examinations are required for diagnosis confirmation.

Pitfalls of diffusion-weighted imaging of the female pelvis

Diffusion-weighted imaging (DWI) is widely used in protocols for magnetic resonance imaging (MRI) of the female pelvis. It provides functional and structural information about biological tissues, without the use of ionizing radiation or intravenous administration of contrast medium. High signal intensity on DWI with simultaneous low signal intensity on apparent diffusion coefficient maps is usually associated with malignancy. However, that pattern can also be seen in many benign lesions, a fact that should be recognized by radiologists. Correlating DWI findings with those of conventional (T1- and T2-weighted) MRI sequences and those of contrast-enhanced MRI sequences is mandatory in order to avoid potential pitfalls. The aim of this review article is the description of the most relevant physiological and benign pathological conditions of the female pelvis that can show restricted diffusion on DWI.

[Ovarian Sertoli-Leydig tumor: A tricky tumor]

We report the case of a 15 years old teenage girl presenting with a primary amenorrhea and hypervirilisation symptoms. The clinical assessement found a 16cm wide heterogenous ovarian mass testosteronemia and alpha-foeto protein levels were increased. On gross exam the tumor was solid and cystic, multilocular containing serous and mucinous liquids. Microscopically, there was a sertoli cells rich solid area in which the cells had a trabecular and nested organization with Leydig cells between them and there was also a cystic area made of glandular structures lined with an intestinal muco-secreting epithelium. Next to these area, there were Sertoli cells and an oedematous stroma. The immunostaining showed that the Sertoli cells expressed, among others, the inhibine and the glands expressed the cytokeratins 7 and 20. A Sertoli and Leydig cells tumor of intermediate differentiation with heterologous elements diagnostic was made. This is a rare tumor, representing less than 0.5% of ovary tumors. Well differentiated tumors are not frequent. In one third of the cases, there are hypervirilisation symptoms, the imaging exams will serve to narrow the diagnosis and to do a full work-up to establish an extension. There are several histologic sub types caracterised by the existence of retiforms structures or heterologous elements. There are no specific immunostainings, this will only help to narrow the diagnosis and rule out some hypothesis. There are no guidelines for the management of the patients, indeed each center has its own practices. Those tumors have quite a good prognosis thanks to their early diagnosis at a stade where they are still confined to the ovary.

Value of Diffusion-Weighted Magnetic Resonance Imaging in the Characterization of Complex Adnexal Masses

Aims and background

The aim of the study was to define the role of diffusion-weighted imaging in the characterization of adnexal complex masses, with particular regard to the distinction between benign and malignant lesions. Conflicting results on this topic have emerged from studies in the last decade, with a consequent substantial limitation to the use of this relatively novel technique in clinical practice.

Methods and study design

Magnetic resonance imaging examinations performed on 91 patients with ovarian masses (56 benign, 35 malignant) were retrospectively evaluated by two observers unaware of the final histopathological diagnosis. Diffusion-weighted sequences with b values of 0, 500 and 1000 were performed in all cases, and apparent diffusion coefficient maps were automatically generated. The signals of both the cystic and solid components of the ovarian masses were evaluated on T2-weighted and diffusion-weighted images acquired with a b value of 1000. Apparent diffusion coefficient values were measured in all cases.

Results

With regard to the solid components, hypointensity on both the T2-weighted and diffusion-weighted images has proved to be a reliable indicator of benignancy. In contrast, hyperintensity on both sequences was suggestive of malignancy. Signal intensity of the cystic components and apparent diffusion coefficient values of both components have not proven useful in characterization of the masses.

Conclusions

Only the definition of the signal intensities on diffusion-weighted images obtained with the use of high b values on the solid component of a complex adnexal mass is useful to characterize an ovarian mass as benign or malignant.

An elderly woman with a mediastinal granulosa cell tumour: a rare presentation

Mediastinal lesions occur in a wide variety of clinical conditions. Metastatic granulosa cell tumour (GCT) in the mediastinum is a rare occurrence. We report a case of a woman who had a metastatic (GCT) in her mediastinum 40 years after treatment of the initial neoplasm. Surgical resection of the mediastinal mass revealed a low‐grade epithelioid neoplasm with coffee bean‐shaped nuclei and immunohistochemical stains that were consistent with metastatic GCT.