Bifocal intracranial tumors of nongerminomatous germ cell etiology: diagnostic and therapeutic implications

Pediatric Suprasellar Tumors: Unveiling the Mysteries of Craniopharyngioma and Germ Cell Tumors-Insights From Diagnosis to Advanced Therapeutics

BACKGROUND

Pediatric suprasellar tumors represent a unique and intricate challenge in the landscape of pediatric neuro-oncology.

METHODS

We conducted an in-depth literature review, focusing on large clinical trials and major publications in pediatric suprasellar tumors, particularly craniopharyngiomas and germ cell tumors, to provide a comprehensive perspective on the challenges in the diagnosis, treatment, and molecular aspects of these tumors.

RESULTS

Nestled within the critical confines of the suprasellar region, these tumors manifest against the backdrop of crucial growth and developmental processes. The suprasellar region, housing the pituitary gland and surrounding structures, plays a pivotal role in orchestrating hormonal regulation and growth. The emergence of tumors within this delicate terrain introduces a complex array of challenges, encompassing neurological, endocrinological, and developmental dimensions from damage to the hypothalamic-pituitary axis.

CONCLUSIONS

This article provides a thorough exploration of pediatric craniopharyngiomas and germ cell tumors, elucidating their clinical presentations, treatment modalities, and outcomes. The focused analysis aims to deepen our understanding of these tumors by offering insights for refined clinical management and improved patient outcomes.

Effect of delayed diagnosis on neuroendocrine function in individuals with suprasellar germ cell tumors

Purpose

The impact of delayed diagnosis on tumor-related prognosis appears to be minimal in individuals with intracranial germ cell tumors (iGCTs). However, its effect on neuroendocrine functions remains unclear. We aimed to assess the effects of delayed diagnosis on neuroendocrine function in individuals with suprasellar GCTs.

Methods

We conducted a retrospective cohort study of 459 individuals with suprasellar GCTs and categorized them into two groups based on disease duration: delayed diagnosis (> 6 months) and non-delayed diagnosis (≤ 6 months). We compared endocrinological symptoms, neuroendocrine dysfunction and its grading (categorized into 0-3 grades based on severity), and recovery from neuroendocrine dysfunction in both groups.

Results

Patients with delayed diagnosis exhibited higher incidences of amenorrhea, slow growth, fatigue, and polyuria/polydipsia. Neuroendocrine dysfunction, including central adrenal insufficiency (CAI), central hypothyroidism (CHT), arginine vasopressin deficiency (AVP-D), growth hormone deficiency, hypogonadism, and hyperprolactinemia, was more pronounced in the delayed diagnosis group at diagnosis, the end of treatment, and the last follow-up. Furthermore, individuals with delayed diagnosis showed higher grades of neuroendocrine dysfunction at diagnosis (OR=3.005, 95% CI 1.929-4.845, p<0.001), end of oncologic treatment (OR=4.802, 95% CI 2.878-8.004, p<0.001), and last follow-up(OR=2.335, 95% CI 1.307-4.170, p=0.005) after adjusting for confounders. Finally, less recovery, particularly in CAI, CHT, and AVP-D, was seen among the group with delayed diagnosis after treatment.

Conclusion

Among individuals with suprasellar GCTs, delayed diagnosis is associated with increased, more severe, and less recovered neuroendocrine dysfunction, emphasizing the importance of early diagnosis and treatment to reduce neuroendocrine dysfunction.

Bifocal germ cell tumor of pineal germinoma and neurohypophyseal embryonal carcinoma: illustrative case

BACKGROUND

Bifocal germ cell tumors, with primarily identical tissue composition, occur concurrently in the neurohypophyseal and pineal regions.

OBSERVATIONS

A 16-year-old male patient exhibited increased intracranial pressure symptoms, with concurrent tumors in the pineal and neurohypophyseal regions, causing obstructive hydrocephalus. His serum human chorionic gonadotropin level was elevated, measuring 506.6 mIU/mL. Upon gross endoscopic examination, the pineal tumor appeared white, whereas the neurohypophyseal tumor appeared red and hemorrhagic. Because of the limited sample size of the latter, a frozen section biopsy was feasible only for the pineal lesion, which indicated the presence of a germinoma. Subsequently, carboplatin and etoposide were administered, resulting in the reduction of the pineal tumor, but no effect was observed in the neurohypophyseal tumor. Histopathological analysis confirmed the pineal lesion as a germinoma, whereas the neurohypophyseal lesion was an embryonal carcinoma. Thus, the treatment was altered to ifosfamide, carboplatin, and etoposide (ICE), leading to a response in both tumors. The patient underwent three additional cycles of ICE therapy and high-dose chemotherapy, followed by whole craniospinal irradiation, achieving complete remission.

LESSONS

Although most bifocal germ cell tumors share the same histological tissue, occasional differences may arise, necessitating separate biopsies for accurate assessment.

Intracranial germ cell tumors: a view of the endocrinologist

Intracranial germ cell tumors (iGCTs) are rare malignant neoplasms that mainly affect children and adolescents. The incidence, clinical presentation, and prognosis of iGCTs exhibit high heterogeneity. Previous studies have primarily focused on eliminating tumors, reducing tumor recurrence, and improving survival rates, while neglecting the impact of the tumors and their treatment on neuroendocrine function. Throughout the entire course of the disease, neuroendocrine dysfunction may occur and is frequently overlooked by oncologists, neurosurgeons, and radiologists. Endocrinologists, however, are more interested in this issue and have varying priorities at different stages of the disease. From onset to the diagnostic phase, most patients with iGCTs may present with symptoms related to impaired neuroendocrine function, or even experience these symptoms as their first indication of the condition. Particularly, a minority of patients with sellar/suprasellar lesions may exhibit typical imaging features and elevated tumor markers long after the onset of initial symptoms. This can further complicate the diagnosis process. During the peritumor treatment phase, the neuroendocrine function shows dynamic changes and needs to be evaluated dynamically. Once diabetes insipidus and dysfunction of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axes occur, hormone replacement therapy should be administered promptly to ensure successful tumor treatment for the patient. Subsequently, during the long-term management phase after the completion of tumor treatment, the evaluation of growth and development as well as corresponding hormone replacement therapy are the most concerning and complex issues. Thus, this paper reviews the interest of endocrinologists in iGCTs at different stages.

Unraveling the impact of upfront chemotherapy and proton beam therapy on treatment outcome and follow-up in central nervous system germ cell tumors: a single center experience

Background

Germ cell tumors (GCT) account for a minority of central nervous system (CNS) malignancies, highly prevalent in adolescents and young adults. Despite their aggressive biological behavior, prognosis is excellent in most cases with risk stratified treatment, consisting in a combination of chemotherapy and radiotherapy. Whole ventricular irradiation (WVI) and craniospinal irradiation, the treatment of choice for localized and metastatic disease, pose significant risk of collateral effects, therefore proton beam radiation (PBT) has been recently proposed for its steep dose fallout.

Materials and methods

We report our experience in a consecutive series of 17 patients treated for CNS GCT at our Institution from 2015 to 2021.

Results

Most frequent lesion location were sellar/suprasellar (35%) and bifocal germinoma (35%), followed by pineal (18%) and thalamic (12%). Two patients (12%), had evidence of disseminated disease at the time of diagnosis. At the latest follow-up all but one patient showed complete response to treatment. The only relapse was successfully rescued by additional chemotherapy and PBT. PBT was well tolerated in all cases. No visual, neurological or endocrinological worsening was documented during and after treatment. Neuropsychological evaluation demonstrated preservation of cognitive performance after PBT treatment.

Conclusions

Our data, albeit preliminary, strongly support the favourable therapeutic profile of PBT for the treatment of CNS germ cell tumors.

Update on MRI in pediatric intracranial germ cell tumors-The clinical and radiological features

Intracranial germ cell tumors (iGCTs) are uncommon brain tumors that mainly occur in children. Differing in histology, location, and gender of the patients, iGCTs are often divided into germinomas and non-germinomatous germ cell tumors (NGGCTs). Early diagnosis and timely treatment are crucial to iGCTs, the subtypes of which have substantial variations. This review summarized the clinical and radiological features of iGCTs at different sites, and reviewed the recent advances in neuroimaging of iGCTs, which can help predict tumor subtypes early and guide clinical decision-making.

Differentiation between germinoma and other pineal region tumors using diffusion-and susceptibility-weighted MRI

PURPOSE

To evaluate the effectiveness of diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) for differentiation between germinoma and other pineal region tumors.

METHOD

This retrospective study consisted of 72 patients with pathologically proven pineal region tumors between January 2010 and August 2020. Tumors were classified as germinomas (40), non-germinomatous germ cell tumors (11) (NGGCT), pineal parenchymal tumors (10) (PPT), and other types of tumors (11). Visual scale score, ADC values and SWI intratumoral susceptibility signal (ITSS) score were analyzed and compared to histopathology data.

RESULTS

The mean apparent diffusion coefficient (ADCmean) and minimum apparent diffusion coefficient (ADCmin) ratio of germinoma were significantly lower than NGGCT. ADCmean or ADCmin cut-off ratio of ≤ 1.48 or ≤ 1.32 allowed for discrimination between germinoma and NGGCT with sensitivity and specificity of 100 % and 63.6 %. An ADCmin cut-off ratio of ≥ 0.93 allowed for discrimination between germinoma and PPT with sensitivity and specificity of 60 % and 80.0 %. ADCmin cut-off ratio of ≤ 1.15 allowed for discrimination of germinoma from other types of tumors with sensitivity and specificity of 87.5 % and 54.5 %.

CONCLUSIONS

ADC ratio can differentiate germinoma from other types of pineal region tumors. Our initial results suggest that ITSS score was not significantly correlated with specific histology subtype.

A 2-step prediction model for diagnosis of germinomas in the pineal region

Background

Germinomas are sensitive to radiation and chemotherapy, and their management distinctly differs from other kinds of pineal region tumors. The aim of this study was to construct a prediction model based on clinical features and preoperative magnetic resonance (MR) manifestations to achieve noninvasive diagnosis of germinomas in pineal region.

Methods

A total of 126 patients with pineal region tumors were enrolled, including 36 germinomas, 53 nongerminomatous germ cell tumors (NGGCTs), and 37 pineal parenchymal tumors (PPTs). They were divided into a training cohort (n = 90) and a validation cohort (n = 36). Features were extracted from clinical records and conventional MR images. Multivariate analysis was performed to screen for independent predictors to differentiate germ cell tumors (GCTs) and PPTs, germinomas, and NGGCTs, respectively. From this, a 2-step nomogram model was established, with model 1 for discriminating GCTs from PPTs and model 2 for identifying germinomas in GCTs. The model was tested in a validation cohort.

Results

Both model 1 and model 2 yielded good predictive efficacy, with c-indexes of 0.967 and 0.896 for the diagnosis of GCT and germinoma, respectively. Calibration curve, decision curve, and clinical impact curve analysis further confirmed their predictive accuracy and clinical usefulness. The validation cohort achieved areas under the receiver operating curves of 0.885 and 0.926, respectively.

Conclusions

The 2-step model in this study can noninvasively differentiate GCTs from PPTs and further identify germinomas, thus holding potential to facilitate treatment decision-making for pineal region tumors.

A Case of Non-Germinomatous Germ Cell Tumors of the Frontal Lobe Arising From the Lateral Ventricle With a Synchronous Pineal Lesion

Non-germinomatous germ cell tumours (NGGCT) are rare intracranial tumours that account for 1% to 3% of cases. They are usually seen in the pineal and suprasellar regions. NGGCT of the frontal lobe arising from the lateral ventricle with a synchronous pineal lesion is uncommon. We present a case of NGGCT with multifocal lesions in the pineal gland, frontal lobe, and pons treated with chemotherapy followed by craniospinal irradiation (CSI).

Imaging response assessment for CNS germ cell tumours: consensus recommendations from the European Society for Paediatric Oncology Brain Tumour Group and North American Children's Oncology Group

Homogeneous and common objective disease assessments and standardised response criteria are important for better international clinical trials for CNS germ cell tumours. Currently, European protocols differ from those of North America (the USA and Canada) in terms of criteria to assess radiological disease response. An international working group of the European Society for Paediatric Oncology Brain Tumour Group and North American Children's Oncology Group was therefore established to review existing literature and current practices, identify major challenges regarding imaging assessment, and develop consensus recommendations for imaging response assessment for patients with CNS germ cell tumours. New clinical imaging standards were defined for the most common sites of CNS germ cell tumour and for the definition of locoregional extension. These new standards will allow the evaluation of response to therapy in patients with CNS germ cell tumours to be more consistent, and facilitate direct comparison of treatment outcomes across international studies.

Unusual presentation of the germinoma: A 26-year-old female

Background:

Germinoma is a rare lesion found commonly in the pineal and suprasellar regions of the brain. Clinical presentation mainly involves the location and size of the tumor and the patient age. Endocrine abnormalities are the most common symptom.

Case Presentation:

The patient was a 26-year-old Iranian female who suffered from germinoma for a long time and was referred to Loghman Hakim Hospital for amenorrhea, polyuria, and polydipsia. Despite diagnostic challenges, she was finally diagnosed with suprasellar germinoma after endoscopic transsphenoidal surgery, followed by radiotherapy and medical interventions to complement the surgery.

Conclusion:

It is important to be able to diagnose the patient's problem at an early stage based on their history, hormonal profile, laboratory results and radiological view.

In and around the pineal gland: a neuroimaging review

Lesions arising in or around the pineal gland comprise a heterogeneous group of pathologies ranging from benign non-neoplastic cysts to highly malignant neoplasms. Pineal cysts are frequently encountered as an incidental finding in daily radiology practice but there is no universal agreement on the criteria for, frequency of, and duration of follow-up imaging. Solid pineal neoplasms pose a diagnostic challenge owing to considerable overlap in their imaging characteristics, although a combination of radiological appearances, clinical findings, and tumour markers allows for narrowing of the differential diagnosis. In this review, we describe the radiological anatomy of the pineal region, clinical symptoms, imaging appearances, and differential diagnosis of lesions arising in this area, and highlight the clinical management of these conditions.

Intracranial germ cell tumors in Adolescents and Young Adults: European and North American consensus review, current management and future development

The incidence of intracranial germ cell tumors (iGCT) is much lower in European and North American (E&NA) than in Asian population. However, E&NA cooperative groups have simultaneously developed with success treatment strategies with specific attention paid to long-term sequelae. Neurological sequelae may be reduced by establishing a diagnosis with an endoscopic biopsy and/or cerebrospinal fluid (CSF) and/or serum analysis, deferring the need to perform a radical surgery. Depending on markers and/or histological characteristics, patients are treated as either germinoma or non-germinomatous germ cell tumors (NGGCT). Metastatic disease is defined by a positive CSF cytology and/or distant drops in craniospinal MRI. The combination of surgery and/or chemotherapy and radiation therapy is tailored according to grouping and staging. With more than 90% 5-year event-free survival (EFS), localized germinomas can be managed without aggressive surgery, and benefit from chemotherapy followed by whole ventricular irradiation with local boost. Bifocal germinomas are treated as non-metastatic entities. Metastatic germinomas may be cured with craniospinal irradiation. With a 5-year EFS over 70%, NGGCT benefit from chemotherapy followed by delayed surgery in case of residual disease, and some form of radiotherapy. Future strategies will aim at decreasing long-term side effects while preserving high cure rates.

The Japan Society for Neuro-Oncology Guideline on the Diagnosis and Treatment of Central Nervous System Germ Cell Tumors

Primary CNS germ cell tumors (GCTs) are rare neoplasms predominantly observed in the pediatric and young adult populations. In line with the hypothesis that the primordial germ cell is the cell-of-origin, histopathological examinations for this pathology involve a diverse range of components mirroring the embryogenic developmental dimensions. Chemotherapy and radiotherapy are the mainstays of treatment, with surgery having a limited role for diagnosis and debulking of residual tissue after treatment. While better management has been achieved over recent decades by modifying radiation coverage and selecting appropriate chemotherapy, standardization of treatment remains challenging, partly due to the low volume of cases encountered in each institution. As the incidence is higher in East Asia, including Japan, the Japan Society for Neuro-Oncology established a multidisciplinary task force to create an evidence-based guideline for CNS GCTs. This guideline provides recommendations for multiple dimensions of clinical management for CNS GCTs, with particular focus on diagnostic measures including serum markers, treatment algorithms including surgery, radiotherapy and chemotherapy, and under-investigated but important areas such as treatment for recurrent cases, long-term follow-up protocols and long-term sequelae. This guideline serves the purpose of helping healthcare professionals keep up to date with current knowledge and standards of management for patients with this rare disease in daily clinical practice, as well as driving future translational and clinical research by recognizing unmet needs concerning this tumor.

Clinical outcomes of pediatric patients with autism spectrum disorder and other neurodevelopmental disorders and intracranial germ cell tumors

INTRODUCTION

Intracranial germ cell tumors (IGCTs) are rare tumors of the central nervous system with peak incidence around puberty. Given the developmental origins of IGCTs, we investigated the prevalence of neurodevelopmental disorders (NDDs) in patients with IGCTs and characterized outcomes for patients with NDD and IGCTs.

METHODS

A retrospective review of medical records was conducted for 111 patients diagnosed with IGCTs between 1998 and 2018 and evaluated at the Massachusetts General Hospital. Kaplan-Meier method and log-rank test was used for survival analyses. Cox regression analyses were performed for parameters associated with progression-free survival (PFS).

RESULTS

Median age at IGCT diagnosis was 12.8 years (range: 4.3-21.7) and median follow-up was 6.5 years (range: 0.2-20.5). Eighteen patients were diagnosed with NDDs prior to IGCT diagnosis, including five patients with autism spectrum disorder (ASD). Of the 67 patients with pure germinomas, four (6.0 %) had prior ASD diagnoses. Patients with NDD had significantly inferior PFS in the nongerminomatous germ cell tumor (NGGCT) cohort. On univariate and multivariable analyses, craniospinal irradiation (CSI) was significantly associated with improved PFS in the NGGCT cohort.

CONCLUSIONS

Our study found an ASD prevalence in the pure germinoma cohort more than threefold greater than the national prevalence, suggesting an association between ASD and pure germinomas. Furthermore, patients with NDD and NGGCT had worse PFS, possibly due to fewer patients with NDD receiving CSI. Future prospective studies with larger cohorts are needed to examine associations between NDDs and IGCTs, and further characterize outcomes for patients with NDDs and IGCTs.

So-called bifocal tumors with diabetes insipidus and negative tumor markers: are they all germinoma?

BACKGROUND

The Delphi consensus statements on the management of germ cell tumors (GCTs) failed to reach agreements on the statement that the cases with (i) pineal and neurohypophyseal bifocal lesion, (ii) with diabetes insipidus, and (iii) with negative tumor markers can be diagnosed as germinoma without histological verification. To answer this, multicenter retrospective analysis was performed.

METHODS

A questionnaire on clinical findings, histological diagnosis, and details of surgical procedures was sent to 86 neurosurgical and 35 pediatrics departments in Japan.

RESULTS

Fifty-one institutes reported 132 cases that fulfilled the 3 criteria. Tissue sampling was performed in 91 cases from pineal (n = 44), neurohypophyseal (n = 32), both (n = 6), and distant (n = 9) lesions. Histological diagnosis was established in 89 cases: pure germinoma or germinoma with syncytiotrophoblastic giant cells in 82 (92.1%) cases, germinoma and mature teratoma in 2 cases, and granulomatous inflammation in 2 cases. Histological diagnosis was not established in 2 cases. Although no tumors other than GCTs were identified, 3 (3.4%) patients had non-germinomatous GCTs (NGGCTs). None of the patients developed permanent complications after endoscopic or stereotactic biopsy. Thirty-nine patients underwent simultaneous procedure for acute hydrocephalus without permanent complications, and hydrocephalus was controlled in 94.9% of them.

CONCLUSION

All patients who fulfilled the 3 criteria had GCTs or granulomatous inflammation, but not other types of tumors. However, no fewer than 3.4% of the patients had NGGCTs. Considering the safety and the effects of simultaneous procedures for acute hydrocephalus, biopsy was recommended in such patients.

Epidemiology, natural history, and optimal management of neurohypophyseal germ cell tumors

OBJECTIVE

Intracranial germ cell tumors (iGCTs) often arise at the neurohypophysis, their second most common origination, following the pineal region. Neurohypophyseal iGCTs present with stereotypical symptoms, including pituitary dysfunction and visual field deficit, due to their suprasellar location. The goal of this study was to present a large, longitudinal single-institution experience with neurohypophyseal iGCTs to better understand their natural history and identify opportunities for further improvement in treatment outcomes.

METHODS

This is a retrospective, single-institution cohort study of neurohypophyseal iGCTs treated between 1988 and 2017, with a focus on the epidemiology, presentation, natural history, and treatment.

RESULTS

Thirty-five neurosurgically managed patients met inclusion criteria; the median age was 18 years (3 months to 49 years), and 74% of patients were male (n = 26). Thirty-one tumors were germinomas, and 4 were nongerminomatous iGCTs. Presenting symptoms included pituitary insufficiency in 76% (n = 25), visual deficit in 45% (n = 15), and diabetes insipidus (DI) in 61% (n = 20) of patients. Index symptoms included isolated DI in 10 (36%), isolated hormone deficiency in 14 (50%), and concomitant DI and hormone deficiency symptoms in 4 (14%). Radiographic diagnostic latency was common, occurring at a median of 363 days (range 9-2626 days) after onset of the first symptoms and was significantly associated with both DI and hormone deficiency as the index symptoms (no DI vs DI: 360 vs 1083 days, p = 0.009; no hormone deficiency vs hormone deficiency: 245 vs 953 days, p = 0.004). Biochemical abnormalities were heterogeneous; each pituitary axis was dysfunctional in at least 1 patient, with most patients demonstrating at least 2 abnormalities, and pretreatment dysfunction demonstrating a nonsignificant trend toward association with long-term posttreatment hormone supplementation. Among germinomas, whole-brain or whole-ventricle radiotherapy demonstrated significantly improved progression-free and overall survival compared with local therapy (p = 0.009 and p = 0.004, respectively).

CONCLUSIONS

Neurohypophyseal iGCTs are insidious tumors that may pose a diagnostic dilemma, as evidenced by the prolonged latency before radiographic confirmation. Serial imaging and close endocrine follow-up are recommended in patients with a characteristic clinical syndrome and negative imaging, due to the propensity for radiographic latency. Pretreatment biochemical abnormalities may indicate higher risk of posttreatment pituitary insufficiency, and all patients should receive careful endocrine follow-up. Local radiotherapy is prone to treatment failure, while whole-ventricle treatment is associated with improved survival in germinomas.

Detecting non-germinomatous germ cell tumor component by arterial spin labeling perfusion-weighted MR imaging in central nervous system germ cell tumor

PURPOSE

Differentiating between germinoma and non-germinomatous germ cell tumor (NGGCT) is important because sensitivity to chemotherapy and/or radiotherapy is quite different between these two subgroups. In this study, we evaluated whether the arterial spin labeling (ASL) based perfusion-weighted imaging (PWI) could provide additional information for the differential diagnosis between germinoma and NGGCT.

METHOD

Between 2011 and 2018, 20 patients with central nervous system (CNS) germ cell tumor (GCT) who underwent preoperative MR imaging including ASL-PWI were enrolled in this study. Relative tumor blood flow (rTBF) was evaluated on ASL-PWI by manually placing regions of interest at gadolinium enhanced part of the tumors and normal subcortical white matter. Presence of intratumoral T1 hyperintense foci and apparent diffusion coefficient (ADC) were also evaluated. The final diagnosis was made by the combination of tumor markers and the histological diagnosis.

RESULTS

Among 20 patients of CNS-GCT, 11 were diagnosed as germinoma and 9 were diagnosed as NGGCT. In the germinoma subgroup, the rTBF ranged from 0.90 to 1.71 (mean 1.21, median 1.09), while it ranged from 1.14 to 5.75 (mean 3.91, median 3.31) in NGGCT subgroup. The receiver operating characteristic (ROC) curve showed that calculating rTBF is useful for differentiating between germinoma and NGGCT (area under the curve (AUC) 0.929, P = 0.0012) compared to intratumoral T1 hyperintense foci (AUC 0.788, P = 0.0304) and ADC (AUC 0.919, P = 0.0016).

CONCLUSIONS

High rTBF obtained by ASL-PWI implied the presence of NGGCT component. This information might help in deciding the chemotherapy/radiotherapy intensity.

Pediatric Suprasellar Germ Cell Tumors: A Clinical and Radiographic Review of Solitary vs. Bifocal Tumors and Its Therapeutic Implications

Suprasellar germ cell tumors (S-GCTs) are rare, presenting in either solitary or multifocal fashion. In this study, we retrospectively examine 22 solitary S-GCTs and 20 bifocal germ cell tumors (GCTs) over a 30-year period and demonstrate clinical, radiographic, and prognostic differences between the two groups with therapeutic implications. Compared to S-GCTs, bifocal tumors were almost exclusively male, exhibited higher rate of metastasis, and had worse rates of progression free and overall survival trending toward significance. We also introduce a novel magnetic resonance (MR) imaging classification of suprasellar GCT into five types: a IIIrd ventricle floor tumor extending dorsally with or without an identifiable pituitary stalk (Type Ia, Ib), ventrally (Type III), in both directions (Type II), small lesions at the IIIrd ventricle floor extending to the stalk (Type IV), and tumor localized in the stalk (Type V). S-GCTs almost uniformly presented as Type I-III, while most bifocal GCTs were Type IV with a larger pineal mass. These differences are significant as bifocal GCTs representing concurrent primaries or subependymal extension may be treated with whole ventricle radiation, while cerebrospinal fluid (CSF)-borne metastases warrant craniospinal irradiation (CSI). Although further study is necessary, we recommend CSI for bifocal GCTs exhibiting high-risk features such as metastasis or non-germinomatous germ cell tumor histology.

Integrated clinical, histopathological, and molecular data analysis of 190 central nervous system germ cell tumors from the iGCT Consortium

BACKGROUND

We integrated clinical, histopathological, and molecular data of central nervous system germ cell tumors to provide insights into their management.

METHODS

Data from the Intracranial Germ Cell Tumor Genome Analysis (iGCT) Consortium were reviewed. A total of 190 cases were classified as primary germ cell tumors (GCTs) based on central pathological reviews.

RESULTS

All but one of the cases that were bifocal (neurohypophysis and pineal glands) and cases with multiple lesions including neurohypophysis or pineal gland were germinomas (34 of 35). Age was significantly higher in patients with germinoma than other histologies. Comparison between tumor marker and histopathological diagnoses showed that 18.2% of histopathologically diagnosed germinomas were marker positive and 6.1% of non-germinomatous GCTs were marker negative, suggesting a limitation in the utility of markers or histopathology alone using small specimens for diagnosis. Comparison between local and central histopathological diagnoses revealed a discordance of 12.7%. Discordance was significantly less frequent in biopsy cases, implying difficulty in detecting all histopathological components of heterogeneous GCTs. Germinomas at the typical sites (neurohypophysis or pineal gland) showed a better progression-free survival than those at atypical sites (P = 0.03). A molecular clinical association study revealed frequent mitogen-activated protein kinase (MAPK) pathway mutations in males (51.4% vs 14.3%, P = 0.007), and phosphatidylinositol-3 kinase/mammalian target of rapamycin (PI3K/mTOR) pathway mutations in basal ganglia cases (P = 0.004). Basal ganglia cases also had frequent chromosomal losses. Some chromosomal aberrations (2q, 8q gain, 5q, 9p/q, 13q, 15q loss) showed potential prognostic significance.

CONCLUSIONS

The in-depth findings of this study regarding clinical and molecular heterogeneity will increase our understanding of the pathogenesis of this enigmatic tumor.

Endoscopic Transsphenoidal Approach in Treatment of Germinomas of the Chiasmosellar Region

Introduction

Germinogenic central nervous system (CNS) tumors represent a heterogeneous group of tumors, constituting approximately 0.4% of all primary brain tumors. Removal of the tumor has no prognostic value. In "pure" primary germinomas of the CNS, the alpha-fetoprotein and human chorionic gonadotropin levels are within normal limits, and no specific biochemical tumor markers currently exist for this tumor type, making histological verification crucial for the choice of treatment tactics. When the tumor is located in the chiasmosellar region, one of the possible verification methods is endoscopic endonasal transsphenoidal biopsy.

Objective

The main objective of the study is to demonstrate the feasibility and safety of endoscopic transsphenoidal approach for histological verification of primary germinomas of the CNS with chiasmosellar localization.

Materials and Methods

The current study includes 13 patients with "pure" germinomas of the chiasmosellar region who underwent endoscopic endonasal surgical interventions with subsequent treatment according to the "Germinoma 2008" protocol.

Results

The extent of surgical intervention ranged from biopsy (4) to partial (5) and total (4) removal of the tumor. In all cases, histological verification of the diagnosis was achieved and none of the patients presented with cerebrospinal fluid leaks and/or meningitis in the postoperative period, allowing to evaluate endoscopic intervention in our patient series as safe and effective. Two out of 13 patients were lost to follow-up.

Conclusion

The endoscopic endonasal approach for histological verification and removal of chiasmosellar region germinomas is safe, and in some cases, less traumatic for the patient than transcranial and transventricular approaches.

Pediatric Cancer

In pediatric brain tumors, the intensification of chemotherapy has allowed for a reduction in radiotherapy (RT) volume to an involved field approach, particularly in patients with medulloblastoma. For patients with low-grade gliomas, the trend has remained to delay RT with chemotherapy; however, when RT is used, typically smaller clinical target volume margins are used. For patients with extracranial tumors, intensive chemotherapy to address systemic disease with local control is considered standard. Proton beam therapy shows significant promise in addressing both short-term and long-term toxicities in both central nervous system (CNS) and non-CNS pediatric tumors.

Nonneuroendocrine Neoplasms of the Pituitary Region

CONTEXT

Although most sellar lesions are related to pituitary adenomas, the region gives rise to a variety of neoplasms that can be associated with substantial morbidity and/or mortality.

DESIGN

Information from reviews and guidelines of relevant societies dealing with such neoplasms, as well as articles that have provided new developments that made important contributions to their pathogenesis and treatment up to 2018, were obtained: public indexes such as PubMed/MEDLINE were used with the relevant search items.

RESULTS

Sellar neoplasms have a worse outcome than pituitary adenomas that is related not only to their natural history but also to side effects of therapies and evolving endocrine and/or hypothalamic deficiencies. Recent imaging advances have established the radiological fingerprint of some of these neoplasms, and several chromosomal aberrations have also been identified. Although established approaches along with new surgical and radiotherapeutic approaches remain the main treatment modalities, recent evidence has provided insight into their molecular pathogenesis involving, other than chemotherapy, treatments with targeted agents as in gliomas and craniopharyngiomas bearing BRAF mutations. Development of predictive markers of recurrences may also identify high-risk patients, including proliferative markers and expression of the progesterone receptor in meningiomas, and lead to less aggressive surgery. Owing to the rarity and complexity of these neoplasms, patients should be managed in dedicated centers.

CONCLUSIONS

The diagnosis and management of sellar neoplasms necessitate a multidisciplinary approach. Following evolving recent advances in their diagnosis and therapy, such a multidisciplinary approach needs to be extended to establish evidence-based diagnostic and management plans.

Central Nervous System Germ Cell Tumors: A Review of the Literature

Central nervous system germ cell tumors are rare intracranial tumors that mainly occur in pediatrics with substantial variation in the incidence among different regions and genders. Histologically, central nervous system germ cell tumors can be divided into germinomas and nongerminomatous germ cell tumors. The molecular pathology of central nervous system germ cell tumors, particularly germinomas, is mainly based on the presence of isochromosome 12p, gain-of-function of the KIT gene, and a globally low DNA methylation profile. Diagnoses and differential diagnoses are conducted through imaging, tumor marker detection, surgical biopsy, and cerebrospinal fluid cytology. Germinomas are often treated via whole-ventricular radiotherapy or neoadjuvant chemotherapy combined with reduced-dose whole-ventricular radiotherapy, whereas nongerminomatous germ cell tumors are mainly treated with chemotherapy, surgical resection, and radiotherapy (individually or in combination), depending on tumor composition. Because the main population of patients is pediatric, extending overall survival and reducing treatment side effects should be the main goals of future studies.

Primary Central Nervous System Germ Cell Tumors: A Review and Update

IMPORTANCE

Primary central nervous system (CNS) germ cell tumors (GCT) are a heterogeneous group of tumors that are still poorly understood. In North America, GCTs comprise approximately 1% of primary brain tumors in pediatric and young adult patients. GCTs can occur as pure or mixed subtypes; they are divided into germinomas, which are the most common subtype, and non-germinomatous germ cell tumors (NGGCTs), which consist of approximately one-third of GCTs and include teratomas, embryonal carcinomas, choriocarcinomas, and yolk sac tumors.

OBSERVATIONS

While the etiology of primary CNS GCT is not entirely clear, the various subtypes are lineage-related and may involve progenitor germ cells that fail to migrate and become trapped in midline locations. Primary CNS GCT most commonly arises in the pineal region but also occur in other areas. Presenting symptoms can include headache, Parinaud syndrome, diabetes insipidus, precosious puberty, ataxia, or hemiparesis. Diagnosis of primary CNS GCTs can be difficult and is often delayed. Various imaging studies and tumor markers can assist in specific diagnosis. Treatment plans differ depending on the subtype of GCT and may vary among physicians and institutions. Germinomas have a favorable prognosis with a greater than 90% overall survival, while NGGCTs only have survival rates ranging from 40-70%.

CONCLUSIONS AND RELEVANCE

Germinomas seem to be most effectively treated with chemotherapy and radiation, while NGGCT usually require surgical resection, chemotherapy, and radiation with the exception of mature teratomas frequently curable with surgery alone. Gamma knife radiosurgery is a promising treatment that may be an effective additional treatment option. Cytogenic and molecular analyses are attempting to further specify the different GCT subtypes and are helping to direct the development of distinct therapeutic targets to improve treatment and prognosis.

Reduced-volume radiotherapy for patients with localized intracranial nongerminoma germ cell tumors

Craniospinal irradiation is standard radiotherapy (RT) for localized intracranial nongerminoma germ cell tumors (NGGCT). Given its toxicity, there is interest in using smaller fields. We examined outcomes of NGGCT patients receiving reduced-volume RT at a single institution. Records of 16 patients who received reduced-volume RT as part of definitive treatment between 1996 and 2016 were reviewed. Median age at presentation was 10.8 years (range 4.6-41.0 years). Ten patients had pineal tumors and 6 had suprasellar tumors. All received chemotherapy and 9 patients received second-look surgery thereafter. RT volume was tumor-only to a median of 54 Gy (range 50.4-54 Gy) in 3 patients and whole-ventricle irradiation to a median of 30.6 Gy (range 30.6-36 Gy) with a boost to 54 Gy in 13 patients. Median follow-up was 4.1 years (range 1.9-19.3 years). Three patients recurred locally at a median 9.9 months (range 9.6-10.6 months) after diagnosis, and one of these developed leptomeningeal relapse after 30 months. One patient expired from disease 2.6 years post-diagnosis and another due to stroke 19.3 years post-diagnosis. Fourteen patients are alive with no evidence of disease. Kaplan-Meier estimates of the 4-year overall survival and failure-free survival are 92% (95% confidence interval [CI], 57-99%) and 81% (95% CI 53-94%), respectively. Excellent disease control was observed in these patients with no initial relapses outside of these RT fields. The results of ACNS1123 may better delineate patterns of failure and identify subgroups likely to benefit from this approach.

MRI features of pediatric intracranial germ cell tumor subtypes

Intracranial germ cell tumors differ in histology and location, and require different clinical management strategies. We characterized the imaging features that may aid pre-operative differentiation of intracranial germinomas and non-germinomatous germ cell tumors (NGGCTs). This retrospective study analyzed 85 patients with intracranial germ cell tumors and adequate preoperative or pretreatment MRIs between 2000 and 2013 at our institution. Pretreatment MRI characteristics, apparent diffusion coefficient (ADC) values, tumor histopathology, and patient outcomes were compared. NGGCTs occurred in the pineal region and cerebral hemispheres more often than germinomas; all bifocal lesions were germinomas. NGGCTs (36.6 ± 17.0 mm) were significantly larger than germinomas (25.7 ± 11.6 mm; P = 0.002). The presence of pure solid tumor (45.5 vs. 20.0%, P = 0.033) and an infiltrative margin (20.0 vs. 3.3%, P = 0.035) were significantly more common in germinomas than NGGCTs. The presence of intratumoral T1 hyperintense foci (66.7 vs. 10.9%, P < 0.001) and moderate/marked enhancement (86.7 vs. 50.9%, P < 0.001) were significantly more common in NGGCTs than in germinomas. Mean ADC_mean values (×10^-3 mm²/s) were significantly lower in germinomas (1.113 ± 0.415) than in NGGCTs (2.011 ± 0.694, P = 0.001). Combined a lack of T1 hyperintense foci and an ADC_mean threshold value (1.143 × 10^-3 mm²/s) had the highest specificity (91.3%) and positive predictive value (92.3%), while the combination of lack of a T1 hyperintensense foci, no/mild enhancement, and an ADC_mean threshold value had 100% sensitivity and 100% negative-predictive value for discriminating germinomas from NGGCTs. Pre-operative conventional MRI characteristics and diffusion-weighted MRI help clinicians to assess patients with intracranial germ cell tumors. Tumor size, location, T1 hyperintense foci, intratumoral cystic components, tumor margin and enhancing patterns demonstrate contrast between germinomas and NGGCTs. Serum tumor markers and adjunctive combination with T1 hyperintensity and/or enhancing pattern with ADC offer potential in preoperative differentiating intracranial germinomas and NGGCTs.

Pituitary stalk thickening: the role of an innovative MRI imaging analysis which may assist in determining clinical management

CONTEXT

Disease processes that affect the pituitary stalk are broad; the diagnosis and management of these lesions remains unclear.

OBJECTIVE

The aim was to assess the clinical, biochemical and histopathological characteristics of pituitary stalk lesions and their association with specific MRI features in order to provide diagnostic and prognostic guidance.

DESIGN AND METHODS

Retrospective observational study of 36 patients (mean age 37years, range: 4-83) with pituitary stalk thickening evaluated at a university hospital in Oxford, UK, 2007-2015. We reviewed morphology, signal intensity, enhancement and texture appearance at MRI (evaluated with the ImageJ programme), along with clinical, biochemical, histopathological and long-term follow-up data.

RESULTS

Diagnosis was considered certain for 22 patients: 46% neoplastic, 32% inflammatory and 22% congenital lesions. In the remaining 14 patients, a diagnosis of a non-neoplastic disorder was assumed on the basis of long-term follow-up (mean 41.3months, range: 12-84). Diabetes insipidus and headache were common features in 47 and 42% at presentation, with secondary hypogonadism the most frequent anterior pituitary defect. Neoplasia was suggested on size criteria or progression with 30% sensitivity. However, textural analysis of MRI scans revealed a significant correlation between the tumour pathology and pituitary stalk heterogeneity in pre- and post-gadolinium T1-weighted images (sensitivity: 88.9%, specificity: 91.7%).

CONCLUSIONS

New techniques of MRI imaging analysis may identify clinically significant neoplastic lesions, thus directing future therapy. We propose possible textural heterogeneity criteria of the pituitary stalk on pre- and post-gadolinium T1 images with the aim of differentiating between neoplastic and non-neoplastic lesions with a high degree of accuracy.

Bifocal germinomas in the pineal region and hypothalamo-neurohypophyseal axis: Primary or metastasis?

Whether bifocal germinomas (BFGs) synchronously presenting within the pineal region and the hypothalamo-neurohypophyseal axis (HNA) are primary germinomas of dual-origin remains to be elucidated. We analyzed MRI images and clinical features of 95 neurohypophyseal germinomas and 21 BFG patients and developed a tentative definition of the BFGs. We found dual-primary BFGs (true BFGs) do exist. The fundamental difference between primary and metastatic HNA germinomas was the direction of tumor growth. For a true BFG, the primary HNA tumor grew from the neurohypophysis toward the hypothalamus and almost invaded the whole pituitary stalk. For a false BFG (primary pineal germinoma with HNA metastasis), the metastatic HNA tumor first appeared at the third ventricular floor (TVF), grew toward the neurohypophysis, but commonly did not invade the inferior pituitary stalk. Compared to false BFGs, true BFGs commonly had diabetes insipidus as the first symptom, dysfunction of the anterior pituitary, no high-intensity MRI signal at the posterior pituitary, a larger extension of the HNA tumor, and fewer numbers of remote lesions from cerebrospinal fluid seeding. Accordingly, 12.8% (12/96) of our germinoma patients had true BFGs, and of these, 58.3% (7/12) were free of remote metastases and warranted treatment with limited radiotherapy. True BFGs with remote metastases and all false BFGs should be treated with craniospinal irradiation. We provided evidence for the diagnosis of true BFGs that is useful for radiotherapy strategy, suggesting that the existence of metastasis to other locations is not a diagnostic criterion for a true BFG.

CNS germ cell tumors: a clinical review and future directions

CNS germ cell tumors (GCT) are rare tumors that arise in midline brain regions (mostly pineal or suprasellar). They are of two types, germinoma and nongerminomatous GCT (NGGCT) which include teratoma, choriocarcinoma, yolk sac, embyronal carcinoma and mixed GCT. Tissue is needed for diagnosis unless serum or cerebrospinal fluid markers, b-HCG or AFP, are elevated. Germinomas can be cured with radiation therapy (RT) alone (whole ventricle fields, if localized), but chemotherapy may permit RT dose-reduction. Best outcomes for NGGCT are with RT and chemotherapy. Craniospinal RT is needed for all disseminated tumors and best survival for localized NGGCT has included craniospinal RT. Recent genetic findings in CNS GCT may lead to therapies targeting their oncogenic pathways.

Consensus on the management of intracranial germ-cell tumours

The management of intracranial germ-cell tumours is complex because of varied clinical presentations, tumour sites, treatments and outcomes, and the need for multidisciplinary input. Participants of the 2013 Third International CNS Germ Cell Tumour Symposium (Cambridge, UK) agreed to undertake a multidisciplinary Delphi process to identify consensus in the clinical management of intracranial germ-cell tumours. 77 delegates from the symposium were selected as suitable experts in the field and were invited to participate in the Delphi survey, of which 64 (83%) responded to the invitation. Invited participants represented multiple disciplines from Asia, Australasia, Europe, and the Americas. 38 consensus statements encompassing aspects of intracranial germ-cell tumour work-up, staging, treatment, and follow-up were prepared. To achieve consensus, statements required at least 70% agreement from at least 60% of respondents. Overall, 34 (89%) of 38 statements met consensus criteria. This international Delphi approach has defined key areas of consensus that will help guide and streamline clinical management of patients with intracranial germ-cell tumours. Additionally, the Delphi approach identified areas of different understanding and clinical practice internationally in the management of these tumours, areas which should be the focus of future collaborative studies. Such efforts should translate into improved patient outcomes.

Successful Treatment of Intracranial Germ Cell Tumor: Report of Two Unusual Cases and Literature Review

Primary intracranial germ cell tumor (GCT) is a rare tumor that generally occurs due to developmental anomaly. Although intracranial GCT is sensitive to treatment, a high recurrence rate, treatment-related long-term complications and the heterogeneity of this tumor group make treatment complicated. Moreover, because of its location, hydrocephalus and visual field defect, functional disturbance of the pituitary gland can occur and require attention. Treatment primarily relies on chemotherapy and radiation therapy but the management of intracranial GCT remains unsettled, especially in the case of unusual circumstances such as multifocal tumor or nongerminomatous GCT. Here, we present two unusual cases of intracranial GCT: one case with a bifocal intracranial germinoma, and the other with an intracranial choriocarcinoma. Both cases were treated with neoadjuvant chemotherapy followed by reduced-field radiation therapy without significant treatment-related complication. Further, we performed a PubMed search to investigate the appropriate treatment strategy for this unusual subtype of intracranial GCT.

Understanding the Treatment Strategies of Intracranial Germ Cell Tumors: Focusing on Radiotherapy

Intracranial germ cell tumors (ICGCT) occur in 2-11% of children with brain tumors between 0-19 years of age. For treatment of germinoma, relatively low radiation doses with or without chemotherapy show excellent 10 year survival rate of 80-100%. Past studies showed that neoadjuvant chemotherapy combined with focal radiotherapy resulted in unacceptably high rates of periventricular tumor recurrence. The use of generous radiation volume which covers the whole ventricular space with later boost treatment to primary site is considered as standard treatment of intracranial germinomas. For non-germinomatous germ cell tumors (NGGCT), 10-year overall survival rate is still much inferior than that of intracranial germinoma despite intensive chemotherapy and high-dose radiotherapy. Craniospinal radiotherapy combined with cisplatin-based chemotherapy provides the best treatment outcome for NGGCT; 60-70% of overall survival rate. There is a debate on the surgical role whether surgery can contribute to improved treatment outcome of NGGCT when added to combined chemoradiotherapy. Because higher dose of radiotherapy is required for treatment of NGGCT than for germinoma, it is tested whether whole ventricular irradiation can replace craniospinal irradiation in intermediate risk group of NGGCT to minimize radiation-related late toxicity in the recent studies. To minimize the treatment-related neural deficit and late sequelae while maintaining long-term survival rate of ICGCT patients, optimized administration of chemotherapy and radiotherapy should be selected. Use of technically upgraded radiotherapy modalities such as intensity-modulated radiotherapy or proton beam therapy is expected to bring an improved neurocognitive outcome with longitudinal assessment of the patients.