Imaging findings of ovarian dysgerminoma with emphasis on multiplicity and vascular architecture: pathogenic implications

Ovarian tumors in the pediatric population: An update

Research reveals that 1% of neoplasms in females under 17 years of age are ovarian neoplasms and though usually benign, malignant tumors may occur in the pediatric age group. This review considers various current concepts of these tumors including the epidemiology, risk factors, clinical presentations, diagnosis, differential diagnosis, and treatment options including the need to provide fertility-sparing surgery as well as their potential impacts on the psychological well-being of children and adolescents. We gathered data from the published articles ranging from studies, meta-analyses, retrospective studies, and reviews. We focused on the articles published in English between January 1, 2000, and August 31, 2023. Only a few articles published prior to 2000 were included for historical perspective.

Diffusion-weighted imaging in pediatric extracranial germ cell tumors

BACKGROUND

Germ cell tumors (GCTs) comprise a rare and heterogeneous group of neoplasms presenting different clinical and histological characteristics, leading to a challenging scenario in clinical practice. Diffusion-weighted imaging (DWI) has been suggested as an indirect marker of tumor density and cellularity and could be used to monitor therapeutic response. However, its role in pediatric GCTs needs to be clarified.

PURPOSE

Here, we evaluated the features of DWI in pediatric extracranial GCTs in a reference Brazilian institution.

MATERIAL AND METHODS

We included 43 pediatric patients with primary GCTs treated between 2008 and 2022 in Hospital de Amor de Barretos. The patients' MRI images included T1-weighted without contrast, T2-weighted, DWI and apparent diffusion coefficient (ADC) maps. DWI was evaluated in the section that exhibited the greatest restricted diffusion in the largest hypersignal area of the image. The lowest ADC value was determined to define the region of interest (ROI). We used a small ROI, avoiding necrotic, adipose tissue, noisy or nonenhancing lesion voxels as recommended. ROI determination was established by visual inspection by two radiologists in accordance. We used two values of b (b = 50 mm2/s or b = 800) for ADC values.

RESULTS

The highest mean ADC (mADC) value was observed in pure teratomas (1,403.50 ± 161.76 x10-3 mm2/s; mean ± SD) compared to other histologies (yolk sac, mixed teratoma, dysgerminoma and mixed GCT) of GCT (p<0.001). Furthermore, ROC analysis determined a cutoff mADC value of 1,179.00 x 10-3 mm2/s that differentiated pure teratomas from the other GCT histologies with a sensitivity of 95.8% and a specificity of 92.9% (AUC = 0.979; p<0.01). A significant increase in mADC was observed for malignant GCTs in treatment (1,197.00 ± 372.00 mm2/s; p<0.001) compared to that exhibited at the time of diagnosis (780.00 ± 168.00 mm2/s; mean ± SD. Our findings suggest that mADC assessment could be used as a tool to distinguish pure teratomas from malignant CGT histologies at diagnosis. Additionally, we demonstrated reasonable evidence that it could be used as a complementary tool to monitor treatment response in patients with malignant GCT.

Diagnosis and Management of Dysgerminomas with a Brief Summary of Primitive Germ Cell Tumors

Dysgerminoma represents a rare malignant tumor composed of germ cells, originally from the embryonic gonads. Regarding its incidence, we do not have precise data due to its rarity. Dysgerminoma occurs at a fertile age. The preferred treatment is the surgical removal of the tumor succeeded by the preservation of fertility. Even if a multidisciplinary team, founded in 2009 by a gynecologist, an oncologist, a pediatric oncologist and a pediatric surgeon, under the guidance of the Malignant Germ Cell International Consortium (MaGIC), studies this type of tumor, issues still remain related to the lack of a randomized study and to both the management and understanding of the concept of OMGCTs (ovarian malignant germ cell tumors). The aim of this review is to present from the literature the various approaches for this type of tumor, and, regarding innovative therapies or possible prevention, which can be applied in clinical practice. Multidisciplinarity and treatment in reference centers have proven their usefulness as well.

A Case of Swyer Syndrome Complicated with Left-sided Gonadoblastoma and Asexual Cell Tumor

Introduction: 46,XY pure gonadal dysgenesis (PGD) is also known as Swyer syndrome. The chromosome analysis indicates a 46,XY karyotype. As different degrees of gonadal hypoplasia or degeneration occur in the process of embryonic development due to several factors, gonadal dysplasia or gonadal tumors are probable. Case Presentation: The patient was a 22-year-old female with no menstruation during puberty. Her chest was funnel-shaped, the breast development was classified as Tanner III grade, the vulva was normal, the pubic hair was classified as Tanner II grade, and the vaginal long was 6 cm. The endocrine examination indicated a follicle-stimulating hormone level of 95.0 mIU/mL and an estradiol level of 34.0 pg/mL. Tumor markers, including alpha-fetoprotein (AFP), carbohydrate antigen 125 (CA125), carbohydrate antigen 199 (CA199), and carcinoembryonic antigen (CEA), were normal. Dual-energy X-ray absorptiometry revealed that the bone mineral density was lower than the normal range at this age. Ultrasonography showed a hypoechoic mass in the left adnexal area, considering gonadal tissue with calcification. Pelvic MRI indicated a gonadal malignancy, and the gonadal tissue of the right adnexal area was cord-shaped. The chromosome analysis indicated a 46,XY karyotype. Accordingly, a clinical diagnosis of PGD was established. Moreover, laparoscopic gonadectomy and pathological examination were performed, and a final diagnosis of Swyer syndrome, complicated with a left-sided gonadoblastoma and asexual cell tumor, was made. Conclusion: PGD is associated with a high risk of gonadal tumors. Considering the rarity of this disease, a detailed evaluation of gonadal size and timely preventive gonadectomy are recommended for patients with gonadal dysplasia. Overall, imaging examinations can provide important information for the diagnosis of gonadal dysplasia. MRI can clearly indicate the size and shape of the gonads and the tumor, as well as the relationship between the tumor and the surrounding tissue.

Magnetic resonance imaging of pure ovarian dysgerminoma: a series of eight cases

BACKGROUND

Imaging findings have a prominent role in early and correct identification of ovarian dysgerminoma, the most common ovarian malignant germ cell tumor (OMGCT). Despite Computed Tomography (CT) is widely used, Magnetic Resonance Imaging (MRI) has proved to be superior in adnexal masses characterization. Limited data and small series are available concerning MRI aspects of dysgerminoma.

CASE PRESENTATION

From January 2012 to December 2018, a database of solid ovarian masses was retrospectively reviewed. Eight patients with histologically proven pure ovarian dysgerminoma and complete imaging available were identified and analyzed. Imaging findings were evaluated separately by two radiologists expert in female genito-urinary MRI.

CONCLUSIONS

MRI findings of a lobulated, purely solid, encapsulated mass with hyper-intensity of lobules and hypo-intensity of septa on T2w images contribute to differentiate dysgerminomas from other ovarian neoplasms.

Ovarian dysgerminoma detected by 18F-FDG PET/CT technique: A case report

INTRODUCTION

Ovarian dysgerminoma (OD) mostly affect young women, have a rapid growth rate, and could result in complications such as rupture, hemoperitoneum or torsion, and acute abdomen. However, there have been no reports of OD on F-FDG PET/CT imaging.

PATIENT CONCERNS

A 21-year-old female patient was admitted to our hospital on February 6, 2016, due to "reduced menstrual flow with abdominal distension for 3 months".

DIAGNOSIS

Color Doppler ultrasound showed a large solid mass in the abdomen and pelvis. Serum carbohydrate antigen 125 (CA125) was elevated significantly. Subsequent computed tomography (CT) of chest showed a large effusion in the right thoracic cavity. Abdominal CT scan revealed the presence of a solid mass occupying a large space in the middle and lower abdomen, suggesting that it derived from the left ovary. Then, she underwent F-fluoro-2-deoxy-D-glucose (F-FDG) positron emission tomography (PET)/CT examination for further diagnosis and staging. PET/CT showed a large occupying lesion in the abdomen. The maximum standardized uptake (SUVmax) of F-FDG was 15.8. No obvious hypermetabolic metastases were observed in the other parts of the body. Postoperative pathology and immunohistochemistry confirmed the ovarian dysgerminoma.

INTERVENTIONS

The patient underwent surgery. Chemotherapy was successfully carried out post-operation.

OUTCOMES

Fortunately, the patient is responding well to treatment and the postoperative recurrence-free survival time has been more than 3 years.

CONCLUSION

OD usually occurs in young women and is characterized by large solid pelvic mass. The F-FDG PET/CT scan shows abnormally increased metabolism of the tumor. Because of the high metabolic characteristics, F-FDG PET/CT may be of great significance in the diagnosis and staging of OD.

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.