Pediatric Central Nervous System Germ Cell Tumors: A Review

Treatment Outcome of Response-Based Radiation Therapy in Children and Adolescents With Central Nervous System Nongerminomatous Germ Cell Tumors: Results of a Prospective Study

PURPOSE

The optimal dose and range of radiation therapy for central nervous system nongerminomatous germ cell tumors (NGGCTs) have not been uniformly established. Therefore, this study aimed to investigate the effect of individualized radiation therapy, based on the response to induction chemotherapy combined with surgery, on the prognosis of patients with NGGCTs.

METHODS AND MATERIALS

Based on the imaging examination and tumor markers after induction chemotherapy and pathologic results of second-look surgery, patients with NGGCT received different radiation therapy strategies, including 30.6 Gy whole ventricular irradiation + tumor-bed boost to 54 Gy, 30.6 Gy craniospinal irradiation + tumor-bed boost to 54 Gy, 36 Gy craniospinal irradiation + tumor-bed boost to 54 Gy, and 36 Gy craniospinal irradiation + 54 Gy tumor-bed boost with 45 Gy to metastatic spinal lesions.

RESULTS

A total of 51 patients were enrolled between January 2015 and March 2021, with a median age of 10.3 years. The 3-year event-free survival and overall survival (OS) of the entire cohort were 70.2% ± 6.9% and 77.5% ± 6.0%, respectively. The 3-year OS of patients achieving partial response after induction chemotherapy was higher than that of patients with stable disease (P = .03) or progressive disease (P = .002). The 3-year event-free survival and OS of the 18 patients receiving 30.6 Gy whole ventricular irradiation and 54 Gy tumor-bed boost were 88.9% ± 7.4% and 94.4% ± 5.4%, respectively.

CONCLUSIONS

The results suggest that an individualized radiation therapy strategy based on response to induction chemotherapy and surgery is a feasible and promising means of achieving reduction in dose and extent of radiation in patients while still providing good response.

Effect of Rosmarinic Acid on Cell Proliferation, Oxidative Stress, and Apoptosis Pathways in an Animal Model of Induced Glioblastoma Multiforme

BACKGROUND

In brain tumors, the complexity of the pathophysiological processes such as oxidative stress, cell proliferation, angiogenesis, and apoptosis have seriously challenged the definitive treatment. Rosmarinic acid (RA), as a polyphenolic compound, has been found to prevent tumor progression in some aggressive cancers. This study was designed to evaluate the anticancer effects of RA on brain tumors.

METHOD

Rats were divided into six groups. Implantation of C6 glioma cells was carried out in the caudate nucleus of the right hemisphere. RA at doses of 5, 10, and 20 mg/kg (i.p.) was administered to the treatment groups for seven days. Tumor volume (by MRI imaging), locomotor ability, survival time, histological alterations (by H & E staining), expression of p53 and p21 mRNAs (by RT-PCR), activities of antioxidant enzymes (superoxide dismutase [SOD] and catalase [CAT] by assay kits), expression of caspase-3 and VEGF (by immunohistochemical analysis), and TUNEL-positive cells (by tunnel staining) were analyzed.

RESULTS

The results indicated that the RA at a dose of 20 mg/kg reduced the tumor volume, prolonged survival time, increased p53 and p21 mRNAs, attenuated SOD and CAT activities in tumor tissue, elevated caspase-3, and increased the number of TUNEL-positive cells. Furthermore, histological analysis revealed less invasion of tumor cells into the normal parenchyma in rats treated with RA (20 mg/kg).

CONCLUSION

These findings provide evidence that the ability of RA to reduce tumor volume could be related to factors that modulate oxidative stress (SOD and CAT enzymes), cell proliferation (p53 and p21), and apoptosis (caspase-3).

Mature cystic teratoma of the right cerebellopontine angle: a rare case report

BACKGROUND AND IMPORTANCE

Intracranial mature cystic teratomas are benign neoplasms that commonly occur at the midline. Mature cystic teratomas at the cerebellopontine (CP) angle are very rare. They are unique germ cell tumours curable by safe total surgical resection and have good prognosis. This case report documents the clinical, radiological, histological features and operative findings of mature cystic teratoma at CP angle.

CLINICAL PRESENTATION

We present a rare case of a mature cystic teratoma at the CP angle in a 24-year-old woman who presented with brainstem compression and cranial nerve deficits. Brain MRI showed atypical findings like hyperintense areas in both T1 and T2 weighted images, calcification and diffusion restriction in part of the lesion. She underwent near total resection of the tumour via right retrosigmoid approach. Intraoperatively, the lesion was intra-arachnoidal unlike schwannomas and the cyst contained sebum-like material, fibrous areas with calcification which are unusual features of common CP angle tumours. Histopathological examination showed well differentiated mature tissues from all three germinal layers and confirmed the diagnosis of a mature cystic teratoma arising from the right CP angle. Patient had good outcome with neurologic recovery.

CONCLUSIONS

Mature cystic teratoma is a rare clinical entity and should be considered in patients with CP angle tumours when there are atypical findings in brain MRI imaging. Cysts with sebum-like material, fibrous areas with calcification and poor tumour-arachnoid plane intraoperatively strongly suggest the possibility of mature cystic teratoma.

Clinical characteristics and predictive factors of delayed diagnosis in patients with sellar germ cell tumors

PURPOSE

To investigate the clinical characteristics and predictive factors associated with delayed diagnosis in patients with sellar germ cell tumors (GCTs), aiming for early diagnosis.

METHODS

A total of 345 patients with sellar GCTs were retrospectively collected. Patients were classified into a delayed diagnosis group (> 6 months from onset to diagnosis) and a non-delayed diagnosis group (≤ 6 months). We compared general characteristics, clinical symptoms, diagnostic methods, treatment strategies, tumor prognosis, and pituitary function between the two groups. Predictive factors for delayed diagnosis were explored using multivariate logistic regression analysis.

RESULTS

225 patients (65.2%) experienced delayed diagnosis. Although there was no association between delayed diagnosis and survival rates or tumor recurrence rates, the delayed diagnosis group had a higher incidence of central diabetes insipidus, central adrenal insufficiency, central hypothyroidism, central hypogonadism, and growth hormone deficiency. Moreover, polyuria/polydipsia (OR 5.46; 95% CI 2.33-12.81), slow growth (OR 5.86; 95% CI 2.61-13.14), amenorrhea (OR 6.82; 95% CI 2.68-17.37), and germinoma (OR 4.99; 95% CI 1.08-3.61) were associated with a higher risk of delayed diagnosis, while older age of onset (OR 0.88; 95% CI 0.84-0.94) and nausea/vomiting (OR 0.31; 95% CI 0.15-0.63) contributed to earlier diagnosis.

CONCLUSION

In patients with sellar GCTs, delayed diagnosis is common and linked to increased pituitary dysfunction. The initial symptoms of slow growth, polyuria/polydipsia, and amenorrhea, as well as germinoma with negative tumor markers, predict the possibility of a delayed diagnosis. Early diagnosis is crucial to minimize the impact of sellar GCTs on pituitary function.

Plasma miRNA expression profile in pediatric pineal pure germinomas

Background

Pure germinomas account for 40% of pineal tumors and are characterized by the lack of appreciable tumor markers, thus requiring a tumor biopsy for diagnosis. MicroRNAs (miRNA) have emerged as potential non-invasive biomarkers for germ cell tumors and may facilitate the non-invasive diagnosis of pure pineal germinomas.

Material and methods

A retrospective chart review was performed on all patients treated at the Children's Cancer Hospital Egypt diagnosed with a pineal region tumor between June 2013 and March 2021 for whom a research blood sample was available. Plasma samples were profiled for miRNA expression, and DESeq2 was used to compare between pure germinoma and other tumor types. Differentially expressed miRNAs were identified. The area under the curve of the receive;r operating characteristic curve was constructed to evaluate diagnostic performance.

Results

Samples from 39 pediatric patients were available consisting of 12 pure germinomas and 27 pineal region tumors of other pathologies, including pineal origin tumors [n = 17; pineoblastoma (n = 13) and pineal parenchymal tumors of intermediate differentiation (n = 4)] and others [n = 10; low-grade glioma (n = 6) and atypical teratoid rhabdoid tumor (n = 4)]. Using an adjusted p-value <0.05, three miRNAs showed differential expression (miR-143-3p, miR-320c, miR-320d; adjusted p = 0.0058, p = 0.0478, and p = 0.0366, respectively) and good discriminatory power between the two groups (AUC 90.7%, p < 0.001) with a sensitivity of 25% and a specificity of 100%.

Conclusion

Our results suggest that a three-plasma miRNA signature has the potential to non-invasively identify pineal body pure germinomas which may allow selected patients to avoid the potential surgical complications.

Final report of the phase II NEXT/CNS-GCT-4 trial: GemPOx followed by marrow-ablative chemotherapy for recurrent intracranial germ cell tumors

Background

Patients with relapsed intracranial germinoma can achieve durable remission with standard chemotherapy regimens and/or reirradiation; however, innovative therapies are required for patients with relapsed and/or refractory intracranial nongerminomatous germ cell tumors (NGGCTs) due to their poor prognosis. Improved outcomes have been reported using reinduction chemotherapy to achieve minimal residual disease, followed by marrow-ablative chemotherapy (HDCx) with autologous hematopoietic progenitor cell rescue (AuHPCR). We conducted a phase II trial evaluating the response and toxicity of a 3-drug combination developed for recurrent intracranial germ cell tumors consisting of gemcitabine, paclitaxel, and oxaliplatin (GemPOx).

Methods

A total of 9 patients with confirmed relapsed or refractory intracranial GCT were enrolled after signing informed consent, and received at least 2 cycles of GemPOx, of which all but 1 had relapsed or refractory NGGCTs. One patient with progressive disease was found to have pathologically confirmed malignant transformation to pure embryonal rhabdomyosarcoma (without GCT elements), hence was ineligible and not included in the analysis. Patients who experienced sufficient responses proceeded to receive HDCx with AuHPCR. Treatment response was determined based on radiographic tumor assessments and tumor markers.

Results

A total of 7 patients achieved sufficient response and proceeded with HDCx and AuHPCR, and 5 subsequently received additional radiotherapy. A total of 2 patients developed progressive disease while receiving GemPOx. Myelosuppression and transaminitis were the most common treatment-related adverse events. With a mean follow-up of 44 months, 4 patients (3 NGGCTs, 1 germinoma) are alive without evidence of disease.

Conclusions

GemPOx demonstrates efficacy in facilitating stem cell mobilization, thus facilitating the feasibility of both HDCx and radiotherapy.

Pediatric sellar teratoma - Case report and review of the literature

BACKGROUND

Intracranial teratoma represents a rare neoplasm, occurring predominantly during childhood. Characteristic symptoms depend on the location but are mainly hydrocephalus, visual disturbances, hypopituitarism, and diabetes insipidus. Initial diagnosis can be challenging due to similar radiological features in both teratomas and other lesions such as craniopharyngiomas. Gross total resection is recommended if feasible and associated with a good prognosis.

CASE DESCRIPTION

A 10-year-old girl presented with newly diagnosed growth retardation, fatigue, cephalgia and bilateral hemianopia. Further laboratory analysis confirmed central hypothyroidism and hypercortisolism. Cranial magnetic resonance imaging showed a cystic space-occupying lesion in the sellar and suprasellar compartment with compression of the optic chiasm without hydrocephalus present, suspicious of craniopharyngioma. Subsequently, an endonasal endoscopic transsphenoidal near-total tumor resection with decompression of the optic chiasm was performed. During postoperative recovery the patient developed transient diabetes insipidus, the bilateral hemianopia remained unchanged. The patient could be discharged in a stable condition, while hormone replacement for multiple pituitary hormone deficiency was required. Surprisingly, histopathology revealed conspicuous areas of skin with formation of hairs and squamous epithelia, compatible with a mature teratoma.

CONCLUSIONS

We present an extremely rare case of pediatric sellar teratoma originating from the pituitary gland and a review of literature focusing on the variation in presentation and treatment. Sellar teratomas are often mistaken for craniopharyngioma due to their similar radiographic appearances. However, the primary goal of treatment for both pathologies is to decompress eloquent surrounding structures such as the optic tract, and if applicable, resolution of hydrocephalus while avoiding damage to the pituitary stalk and especially the hypothalamic structures. If feasible, the aim of surgery should be gross total resection.

Special Considerations in Pediatric Endoscopic Skull Base Surgery

Originally pioneered in adults, endoscopic endonasal approaches for skull base pathology are being increasingly applied as a minimally invasive alternative for young children. Intrinsic anatomic differences between these patient populations have sparked discussions on the feasibility, safety, and efficacy of these techniques in pediatric patients. This work aims to serve as a primer for clinicians engaged in the rapidly evolving field of pediatric endoscopic skull base surgery. A succinct overview of relevant embryology, sinonasal anatomy, and diagnostic workup is presented to emphasize key differences and unique technical considerations. Additional discussions regarding select skull base lesions, reconstructive paradigms, potential surgical complications, and postoperative care are also highlighted in the setting of multidisciplinary teams.

Intracranial Germinoma in Two Caucasian American Siblings With Autism Spectrum Disorder

Intracranial germ cell tumors (IGCTs) comprise 3% to 5% of all pediatric brain tumors in the West, with a significantly higher prevalence in Asia. Although these tumors are histologically diverse, repeated somatic variants have been demonstrated. Chromosomal aneuploidies, such as Klinefelter and Down syndromes, are associated with IGCTs, but no familial germline tumor syndromes are currently known. Here, we report the novel case of 2 American siblings with underlying autism spectrum disorder who developed intracranial germinoma within months of each other, in the absence of external risk factors. Extensive genetic testing was performed, including karyotyping, chromosomal microarray, and whole exome and whole genome sequencing, and did not identify any variants accounting for the phenotypes. Despite the absence of overlapping variants, a recent retrospective review demonstrated a threefold greater prevalence of autism spectrum disorder in patients with intracranial germinoma compared with national prevalence. This report highlights the complexity of tumor development, as well as the need for further research regarding IGCTs in a neurodivergent population.

A novel lactate dehydrogenase-based risk score model to predict the prognosis of primary central nervous system germ cell tumor treated with chemoradiotherapy

BACKGROUND

The prognostic role of lactate dehydrogenase (LDH) has been confirmed in many malignant tumors, but the role of serum LDH in primary central nervous system germ cell tumor (GCT) remains unknown. This study aimed to assess the prognostic value of LDH in GCT patients and develop a nomogram to predict prognosis in patients undergoing chemoradiotherapy.

METHODS

A total of 161 patients with GCT were included in this study. Using a restricted cubic spline (RCS) model, the optimal cutoff point for LDH was determined to be 217 U/L. The survival of GCT patients was evaluated using the Kaplan-Meier method and log-rank test to analyze the effects of LDH levels. Univariate Cox regression, multivariate Cox regression, and LASSO Cox regression were conducted to identify prognostic factors, which were incorporated into a nomogram for predicting overall survival (OS). The predictive accuracy of the nomogram was assessed using the C-index, calibration curve, area under the time-dependent receiver operating characteristic curve (time-dependent AUC), and risk group stratification. The net benefits of the nomogram at different threshold probabilities were quantified using decision curve analysis (DCA).

RESULTS

The high-LDH group had significantly shorter OS compared to the low-LDH group (P = 0.016). Based on the SYSUCC cohort, three variables were shown to be significant factors for OS and were incorporated in the nomogram: LDH, histopathology, and dissemination. It showed good discrimination ability, with C-index of 0.789 (95% CI, 0.671-0.907). Additionally, the clinical usefulness of the nomogram was confirmed by calibration curves and time-dependent AUC. DCA further highlighted the potential of the nomogram to guide clinical treatment strategies for patients. Moreover, there was a significant difference in OS among patients categorized into different risk groups (P < 0.001).

CONCLUSION

LDH levels may serve as a reliable predictor for assessing the therapeutic effect of chemoradiotherapy in GCT. The developed nomogram exhibits high accuracy in predicting survival outcomes, aiding in the classification of prognostic groups, and supporting informed clinical decision-making.

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.

Intracranial Germ Cell Tumors

Intracranial germ cell tumors are rare tumors occurring in adolescents and young adults, which include germinomas and non-germinomatous type germ cell tumors (NGGCT). In the past few decades, cooperative trial groups in Europe and North America have developed successful strategies to improve survival outcomes and decrease treatment-related toxicities. New approaches to establishing diagnosis have deferred the need for radical surgery. The 5-year event-free survival (EFS) is above 90% and even patients who present with metastatic germinoma can still be cured with chemotherapy and craniospinal irradiation. The combination of surgery, chemotherapy, and radiation therapy is tailored to patients based on grouping and staging. For NGGCT, neoadjuvant chemotherapy followed by delayed surgery for residual disease and radiotherapy can yield a 5-year EFS of 70%. Further strategies should focus on reducing long-term complications while preserving high cure rates.

Preoperatively difficult-to-diagnose medulla oblongata germinoma: A case report and literature review

Background

Intracranial germinomas are rare tumors, accounting for 0.5-2% of primary intracranial neoplasms. While they typically occur in the pineal gland, suprasellar region, basal ganglia, and thalamus, germinomas arising in the medulla oblongata are exceptionally rare. Diagnosis of medulla oblongata germinoma is challenging, potentially leading to misdiagnosis and poor prognosis.

Case Description

We present a case of a 29-year-old man complaining of left leg numbness. Radiological findings revealed a contrast-enhanced lesion in the medulla oblongata. The patient underwent tumor biopsy, and intraoperative pathological diagnosis (IOD) suspected the diagnosis of medulla oblongata germinoma. He underwent chemoradiotherapy after confirming the diagnosis of germinoma. Intracranial germinoma arising in the medulla oblongata differs from germinomas in other locations due to its higher incidence in individuals in their 20s and a slight female predominance.

Conclusion

When encountering lesions in the medulla oblongata, germinoma should be considered as one of the differential diagnoses, and surgical strategies including IOD should be planned accordingly.

Mature teratoma of conus medullaris: A case report and review of literature

In conus medullaris, mature teratomas are rare. We report a case of a 40-year-old man who presented with urinary incontinence, low back pain, and muscle weakness. Magnetic resonance imaging revealed a mass in conus medullaris (T11-L1), further confirmed as a mature teratoma by pathological examination. We identified 63 cases of conus medullaris teratoma over the past two decades by systematically analyzing the case reports. Findings demonstrated that most cases were diagnosed in the fourth decade of life, with the majority of cases (57.6%) being male. Lower back pain, radiating pain in the extremities, hypoesthesia, and urinary dysfunction are the most common clinical presentations among patients with teratoma of conus medullaris. Mature teratoma is the dominant pathologic subtype of teratomas in this region, comprising more than 95% of cases. Our case highlights the importance of considering spinal teratoma as a differential diagnosis in patients presenting with urinary incontinence and lumbar pain.

Children's Oncology Group's 2023 blueprint for research: Central nervous system tumors

Tumors of the central nervous system (CNS) are a leading cause of morbidity and mortality in the pediatric population. Molecular characterization in the last decade has redefined CNS tumor diagnoses and risk stratification; confirmed the unique biology of pediatric tumors as distinct entities from tumors that occur in adulthood; and led to the first novel targeted therapies receiving Food and Drug Administration (FDA) approval for children with CNS tumors. There remain significant challenges to overcome: children with unresectable low-grade glioma may require multiple prolonged courses of therapy affecting quality of life; children with high-grade glioma have a dismal long-term prognosis; children with medulloblastoma may suffer significant short- and long-term morbidity from multimodal cytotoxic therapy, and approaches to improve survival in ependymoma remain elusive. The Children's Oncology Group (COG) is uniquely positioned to conduct the next generation of practice-changing clinical trials through rapid prospective molecular characterization and therapy evaluation in well-defined clinical and molecular groups.

Treatment outcomes for response-based radiotherapy in children and adolescents with central nervous system germinoma: a prospective study

PURPOSE

The optimal dose and range of radiotherapy for central nervous system (CNS) germinoma have not yet been established. This study aimed to investigate the effects of individualized radiotherapy on the prognosis of patients with germinoma.

METHODS

Based on imaging examination, tumor markers, and pathologic results, patients with germinoma received different radiotherapy strategies, including R1 (24 Gy whole ventricular irradiation + tumor-bed boost to 40 Gy), R2 (24-30 Gy craniospinal irradiation + tumor-bed boost to 54 Gy), R3 (24 Gy craniospinal irradiation + tumor-bed boost to 40 Gy), and R4 (30 Gy craniospinal irradiation + tumor-bed boost to 54 Gy with 45 Gy to spinal metastasis).

RESULTS

A total of 77 patients were enrolled in this study between January 2015 and March 2021. The 3-year event-free survival (EFS) and overall survival (OS) of the whole cohort were 94.7% ± 2.6% and 96.0% ± 2.3%, respectively. The 3-year EFS for patients with localized and metastatic disease were 96.6% ± 2.4% and 89.2% ± 7.2%, respectively. The 3-year EFS of patients receiving R1, R2, R3, and R4 radiotherapy were 100%, 94.1% ± 5.7%, 100%, and 86.2% ± 9.1%, respectively.

CONCLUSION

Good prognosis was still achieved after reducing dose and extent of radiation for the patients who achieved complete response (CR) after induction chemotherapy or pathological CR after second-look surgery.

[Diagnosis of germ cell tumors]

CLINICAL/METHODICAL ISSUE

Intracranial germ cell tumors are rare central nervous system (CNS) diseases in Europa and America. Because of their low frequency and lack of typical imaging features, they represent a difficult diagnosis for any radiologist.

STANDARD RADIOLOGICAL METHODS

Magnetic resonance imaging (MRI) is a sensible diagnostic tool for the initial diagnosis of germ cell tumors, although it has limitations.

METHODOLOGICAL INNOVATIONS

So far, no typical morphologic pattern as a red flag for germ cell tumors has been identified. Correlation with clinical symptoms and laboratory results is mandatory.

PERFORMANCE

In certain cases, combining the location of the tumor and clinical findings may allow a diagnosis to be made even without histologic confirmation.

PRACTICAL RECOMMENDATIONS

In addition to imaging, the radiologist needs the age, background, and laboratory findings to be able to make an accurate diagnosis.

Neuroimaging of pediatric tumors of the sellar region-A review in light of the 2021 WHO classification of tumors of the central nervous system

Sellar/suprasellar tumors comprise about 10% of all pediatric Central Nervous System (CNS) tumors and include a wide variety of entities, with different cellular origins and distinctive histological and radiological findings, demanding customized neuroimaging protocols for appropriate diagnosis and management. The 5th edition of the World Health Organization (WHO) classification of CNS tumors unprecedently incorporated both histologic and molecular alterations into a common diagnostic framework, with a great impact in tumor classification and grading. Based on the current understanding of the clinical, molecular, and morphological features of CNS neoplasms, there have been additions of new tumor types and modifications of existing ones in the latest WHO tumor classification. In the specific case of sellar/suprasellar tumors, changes include for example separation of adamantinomatous and papillary craniopharyngiomas, now classified as distinct tumor types. Nevertheless, although the current molecular landscape is the fundamental driving force to the new WHO CNS tumor classification, the imaging profile of sellar/suprasellar tumors remains largely unexplored, particularly in the pediatric population. In this review, we aim to provide an essential pathological update to better understand the way sellar/suprasellar tumors are currently classified, with a focus on the pediatric population. Furthermore, we intend to present the neuroimaging features that may assist in the differential diagnosis, surgical planning, adjuvant/neoadjuvant therapy, and follow-up of this group of tumors in children.

Cancer Stem Cells in Tumours of the Central Nervous System in Children: A Comprehensive Review

Cancer stem cells (CSCs) are a subgroup of cells found in various kinds of tumours with stem cell characteristics, such as self-renewal, induced differentiation, and tumourigenicity. The existence of CSCs is regarded as a major source of tumour recurrence, metastasis, and resistance to conventional chemotherapy and radiation treatment. Tumours of the central nervous system (CNS) are the most common solid tumours in children, which have many different types including highly malignant embryonal tumours and midline gliomas, and low-grade gliomas with favourable prognoses. Stem cells from the CNS tumours have been largely found and reported by researchers in the last decade and their roles in tumour biology have been deeply studied. However, the cross-talk of CSCs among different CNS tumour types and their clinical impacts have been rarely discussed. This article comprehensively reviews the achievements in research on CSCs in paediatric CNS tumours. Biological functions, diagnostic values, and therapeutic perspectives are reviewed in detail. Further investigations into CSCs are warranted to improve the clinical practice in treating children with CNS tumours.

Mature Teratoma with Somatic-Type Malignancy: An Entity of Unacquaintance-A Case Report

Primary intracranial teratomas are nongerminomatous germ cell tumors. They are infrequent lesions along the craniospinal axis, with their malignant transformation extremely uncommon. A 50-year-old-male patient presented with one episode of generalized tonic-clonic seizure (GTCS), without any neurological deficit. Radiological imaging revealed a large lesion in the pineal region. He underwent gross total excision of the lesion. Histopathological examination was representative of teratoma with adenocarcinomatous malignant transformation. He underwent adjuvant radiation therapy and had an excellent clinical outcome. The present case highlights the rarity of malignant transformation of the primary intracranial mature teratoma.

Precision based approach to tailoring radiotherapy in the multidisciplinary management of pediatric central nervous system tumors

Modern day survivorship from childhood malignancies is estimated to be over 80%. However, central nervous system tumors remain the leading cause of cancer mortality in children and is the most common solid tumor in this population. Improved survivorship is, in part, a result of improved multidisciplinary care, often with a combination of surgery, radiation therapy, and systemic therapy. With improved survival, long term effects of treatment and quality of life impacts have been recognized and pose a challenge to maximize the therapeutic ratio of treatment. It has been increasingly more apparent that precise risk stratification, such as with the inclusion of molecular classification, is instrumental in efforts to tailor radiotherapy for appropriate treatment, generally towards de-intensification for this vulnerable patient population. In addition, advances in radiotherapy techniques have allowed greater conformality and accuracy of treatment for those who do require radiotherapy for tumor control. Ongoing efforts to tailor radiotherapy, including de-escalation, omission, or intensification of radiotherapy, continue to improve as increasing insight into tumor heterogeneity is recognized, coupled with advances in precision medicine employing novel molecularly-targeted therapeutics.

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.

Primary suprasellar germinoma: A series of 15 cases

Primary suprasellar germinoma (PSG) is a rare malignant tumor of the central nervous system. This study aimed to explore the clinical characteristics, treatment protocol, and prognosis of patients with PSG. This case series retrospectively analyzed the clinical data of patients with PSG in Tianjin Huanhu Hospital diagnosed between January 2016 and December 2021. Fifteen patients with an average age of 19.6 years were included, in which nine of them were males. The mean duration between initial symptoms and admission was 17.0 months. The mean follow-up was 40.8 months. Ten patients had polydipsia and polyuria, visual impairments were observed in 8 patients, and 2 cases (13.3%) had symptoms both from suprasellar and pineal regions. All 15 cases were histopathologically confirmed as germinoma through craniotomy or biopsy. Most patients (80%) underwent radiotherapy combined with chemotherapy. During follow-up, all the patients showed a reduction in tumor size, especially in the bifocal cases. Symptoms of polydipsia, polyuria, and visual impairment were markedly relieved to different degrees. All patients had recovered well at discharge. Patients with polydipsia and polyuria took desmopressin daily. A histological confirmation by open biopsy through craniotomy or endoscopic biopsy might be recommended for PSG to start the appropriate treatments. Patients with PSG will usually have a good prognosis, but attention should be paid to the treatment of endocrine deficiencies.

Multiple ectopic germinomas presenting as focal dystonia of fingers: a case report and literature review

BACKGROUND

Intracranial primary germinomas predominantly develop on or near the midline structure in children and young adults and are diagnosed by brain imaging and biopsy. However, if brain imaging and pathology show unusual findings, it becomes difficult to make an accurate diagnosis.

CASE REPORT

Herein, we report the case of a 14-year-old boy who presented with focal dystonia of the fingers as an initial symptom. Magnetic resonance imaging of the brain showed multifocal heterogeneous lesions with solid and cystic components involving the right frontal lobe, corpus callosum, left basal ganglia, and left corona radiata. A stereotactic biopsy of the right frontal lesion revealed several granulomatous areas with abundant inflammatory cells. After immunohistochemical staining, the patient was diagnosed with germinoma and treated with chemoradiotherapy according to the Korean Society for Pediatric Neuro-Oncology protocol. The patient has been in complete remission for five years.

CONCLUSION

Germinomas can develop in intracranial off-midline structures, with unusual clinical, radiological, and pathological presentations. It is important to include intracranial germinomas in the differential diagnosis of infiltrative parenchymal tumors, especially in children.

Brain and Spinal Cord Tumors Among the Life-Threatening Health Problems: An Introduction

As one of the global concerns, cancers, including brain and spinal cord tumors, are responsible for mortalities and irreversible morbidities in the affected patients. Although advancements in molecular pathology and imaging of tumors may have influenced the incidence rate due to higher diagnosis in early stages, exposure to environmental risk factors could be another explanation for increased incidence of these tumors over the past decades. Similar to many other tumors, the CNS tumors begin in cellular dimension with activation of different molecular pathways. Several genetic, epigenetic, and immunologic pathways and processes are already discovered to play roles in pathophysiology of these tumors, which mostly will eventually become symptomatic. Each of these tumors may exhibit imaging characteristics, making it possible to list a series of differential diagnosis before histopathologic examination. Advances in molecular pathology have resulted in better understanding and categorization of CNS tumors, leading to better decision-making on the most appropriate therapeutic approach for each category, as well as proposing new therapeutic modalities to treat these tumors. As an introduction to the 2-volume book, this chapter addressed different types of human brain and spinal cord tumors based on the fifth version of WHO classification of CNS tumors.

Targeted treatment of solid tumors in pediatric precision oncology

The treatment of childhood solid cancer has markedly evolved in recent years following a refined molecular characterization and the introduction of novel targeted drugs. On one hand, larger sequencing studies have revealed a spectrum of mutations in pediatric tumors different from adults. On the other hand, specific mutations or immune dysregulated pathways have been targeted in preclinical and clinical studies, with heterogeneous results. Of note, the development of national platforms for tumor molecular profiling and, in less measure, for targeted treatment, has been essential in the process. However, many of the available molecules have been tested only in relapsed or refractory patients, and have proven poorly effective, at least in monotherapy. Our future approaches should certainly aim at improving the access to molecular characterization, to obtain a deeper picture of the distinctive phenotype of childhood cancer. In parallel, the implementation of access to novel drugs should not only be limited to basket or umbrella studies but also to larger, multi-drug international studies. In this paper we reviewed the molecular features and the main available therapeutic options in pediatric solid cancer, focusing on available targeted drugs and ongoing investigations, aiming at providing a useful tool to navigate the heterogeneity of this promising but complex field.

Brain and Spinal Tumors Originating from the Germ Line Cells

Primary central nervous system germ cell tumors (CNS GCTs) are part of the GCTs in children and adults. This tumor entity presents with geographic variation, age, and sex predilection. There are two age peaks of incidence distribution at the first few months of life and in adolescence. CNS GCTs are heterogeneous in histopathological subtypes, locations, and tumor marker (AFP, β-hCG) secretions. In the WHO CNS tumor classification, GCTS are classified as germinoma and nongerminomatous GCT (NGGCT) with different subtypes (including teratoma). Excluding mature teratoma, the remaining NGGCTs are malignant (NGMGCT). In teratoma, growing teratoma syndrome and teratoma with somatic-type malignancy should be highlighted. The common intracranial locations are pineal region, neurohypophysis (NH), bifocal pineal-NH, basal ganglia, and cerebral ventricle. Above 50% of intracranial GCTs (IGCTs) present obstructive hydrocephalus. Spinal tumors are rare. Age, locations, hydrocephalus, and serum/CSF titer of β-hCG correlate with clinical manifestations. Delayed diagnosis is common in tumors arising in neurohypophysis, bifocal, and basal ganglia resulting in the increasing of physical dysfunction and hormonal deficits. Staging work-up includes CSF cytology for tumor cells and contrast-enhanced MRI of brain and spine for macroscopic metastasis before treatment commences. The therapeutic approach of CNS GCTs integrates locations, histopathology, staging, tumor marker level, and therapeutic classification. Treatment strategies include surgical biopsy/excision, chemotherapy, radiotherapy (single or combination). Secreting tumors with consistent imaging may not require histopathological diagnosis. Primary germinomas are highly radiosensitive and the therapeutic aim is to maintain high survival rate using optimal radiotherapy regimen with/without chemotherapy combination. Primary NGNGCTs are less radiosensitive. The therapeutic aim is to increase survival utilizing more intensive chemotherapy and radiotherapy. The negative prognostic factors are residue disease at the end of treatment and serum or CSF AFP level >1000 ng/mL at diagnosis. In refractory or recurrent NMGGCTs, besides high-dose chemotherapy, new therapy is necessary. Molecular profiling and analysis help for translational research. Survivors of pediatric brain tumors frequently experience cancer-related cognitive dysfunction, physical disability, pituitary hormone deficiency, and other CNS complications after cranial radiotherapy. Continuous surveillance and assessment may lead to improvements in treatment protocols, transdisciplinary interventions, after-treatment rehabilitation, and quality of life.

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.

Clinical Outcomes and Diagnostic Consistency of Serum and CSF Tumor Markers in Pediatric Intracranial Germ Cell Tumors in Thailand: A Multicenter Study

The diagnostic and treatment outcomes of intracranial germ cell tumors (ICGCTs) among low and middle income countries are limited. A total of 63 ICGCTs patients with a median age of 11.6 years were studied. A 30 (47.6%) and 33 (52.4%) patients were classified as pure germinomas and nongerminomatous germ cell tumors (NGGCTs), respectively. The concordances between serum and cerebrospinal fluid (CSF) alpha-fetoprotein (84.3%) and beta-human chorionic gonadotropin (68.4%) were addressed. The 5-year overall survival (OS) and event-free survival (EFS) rates of pure germinomas versus NGGCTs were 83.9 versus 69.1% and 74.6 versus 57.7%, respectively. Patients undergoing radiation had higher 5-year OS and EFS than those without radiation treatment with P < .001. Chemotherapy combined with radiation is a cornerstone treatment to achieve outcomes. Adverse prognostic factors included age <8 years, surgery, and nonradiation treatment. Either serum or CSF tumor markers were adequately required as a diagnostic test among patients with ICGCTs.

Primary central nervous system germ cell tumors in children and young adults: A review of controversies in diagnostic and treatment approach

Primary central nervous system (CNS) germ cell tumors (GCT) are a rare heterogenous group of cancers, arising most commonly in the second decade of life. Through several clinical trials conducted around the world by various groups, the treatment approach for CNS GCT has advanced substantially with generally improved overall outcomes. In recent years, the goal of clinical trials has been focused on reduction of the radiotherapy burden and minimization of long-term toxicity. This review summarizes the current diagnostic and treatment regimens for CNS GCT, examines the controversies associated with these approaches, gaps in contemporary knowledge, and underscores the challenges we face. We also explore future directions in the management of CNS GCT with the ultimate overall aim of preserving curative outcomes, identifying novel biomarkers, and mitigating neurocognitive, endocrine, and psychological toxicity through prospective clinical studies.

High prevalence of overweight/obesity and dyslipidemia in patients with intracranial germ cell tumors

PURPOSE

To evaluate the prevalence of overweight/obesity and dyslipidemia in patients with intracranial germ cell tumor (iGCT), and to explore the risk factors of it.

METHODS

iGCT patients visiting Peking Union Medical College Hospital between Jan 2008 to Oct 2020 were included. The prevalence of overweight/obesity and dyslipidemia was calculated. Mixed-effects models were used to evaluate the relationship between BMI z-scores, concentration of lipid profiles and potential risk factors.

RESULTS

One hundred and six patients were included. The median follow-up time was 27 (IQR 5-59) months. The number of patients diagnosed with overweight/obesity and dyslipidemia were 49 (46.2%) and 86 (81.1%) during visits. Higher BMI z-scores were associated with treatment (mean difference (MD) 0.51, 95%CI 0.31-0.72), surgical biopsies (MD 0.71, 95%CI 0.16-1.25), adrenal insufficiency (MD 0.37, 95%CI 0.07-0.68), hypothyroidism (MD 0.35, 95%CI 0.06-0.63), glucocorticoid supplementation (MD 0.64, 95%CI 0.40-0.87), and thyroxine supplementation (MD 0.48, 95%CI 0.24-0.72). Hypothalamus involvement was associated with increased TC (MD 0.52, 95%CI 0.06-0.98), TG (MD 0.36, 95%CI 0.01-0.72), LDL-C (MD 0.60, 95%CI 0.20-0.98), and decreased HDL-C (MD - 0.23, 95%CI - 0.44 to - 0.02). Higher TC (MD 0.53, 95%CI 0.26-0.80) and LDL-C (MD 0.39, 95%CI 0.17-0.62) were observed in patients after treatment. Glucocorticoid supplementation was associated with increased TC (MD 0.70, 95%CI 0.38-1.03), LDL-C (MD 0.51, 95%CI 0.24-0.78), and HDL-C (MD 0.25, 95%CI 0.09-0.40), while sex hormone supplementation was associated with decreased TC (MD - 0.74, 95%CI - 1.2 to - 0.29) and TG (MD - 0.47, 95%CI - 0.86 to - 0.08).

CONCLUSION

Overweight/obesity and dyslipidemia were high prevalent in iGCT patients and should be screened during follow-ups.

PD-L1 and PD-1 expression in pediatric central nervous system germ cell tumors

Central nervous system (CNS) germ cell tumors (GCTs) represent 2-3% of all primary CNS tumors. The majority are germinomas, which are radiosensitive and have an excellent prognosis. Contrarily, CNS non-germinomatous GCTs (NGGCTs) have less favorable prognosis and require more aggressive treatment. The expression of checkpoint/immune markers in CNS GCTs, particularly NGGCTs, is unknown. We previously reported a case of a patient whose intracranial NGGCT (predominantly choriocarcinoma) responded to immune checkpoint inhibition therapy. This case led us to evaluate our archive of intracranial GCTs for expression of PD-L1 and PD-1. With IRB approval, we searched the pathology archives at our institution for CNS GCTs. Demographic, radiologic, clinical, and histologic information was extracted from the medical records. Immunohistochemistry for lymphocytic markers (CD4, CD8, CD20), PD-1, and PD-L1 was performed. PD-L1 was considered positive if greater than 1% of tumor cells were positive and PD-1 was reported as a percentage of positive inflammatory cells. Fifty cases were identified, including 28 germinomas (mean age at diagnosis: 15.5 years; 17 males, 11 females), and 22 NGGCTs (mean age at diagnosis: 12.0 years, 21 males, 1 female). Germinomas were mostly suprasellar (17/28) and NGGCTs were predominantly pineal (17/22). Twenty-two germinomas (79%) were positive for PD-L1 expression, and 13 NGGCTs (57%) were positive for PD-L1. Cases of choriocarcinoma showed the most diffuse PD-L1 expression. PD-1 expression was seen in lymphocytes among 27/28 of the germinomas and 20/23 of the NGGCTs (ranging from 1-40% of lymphocytes). As expected, larger quantities of inflammatory cells were present in cases of germinoma. We demonstrate immune activity in CNS GCTs, and our results suggest that immune checkpoint inhibitors may be efficacious in the treatment of intracranial GCTs. Among NGGCTs, cases of choriocarcinoma showed the highest expression of PD-L1 in tumor cells, suggesting that this subtype may have the greatest benefit from checkpoint blockade.

Bifocal pineal and suprasellar germinomas with posterior fossa metastases in an adolescent patient

Central nervous system germ cell tumors are rare lesions that are more frequently seen in the pediatric age group. Intracranial germinomas are a type of these germ cell tumors and commonly arise in the pineal region, suprasellar region, or less frequently at both areas (bifocal). Common features of this tumor depend on the location of the lesion(s) and include Parinaud's syndrome, obstructive hydrocephalus, diabetes insipidus, panhypopituitarism, strabismus, and visual acuity defects. We report a case of bifocal pineal and suprasellar germinoma with posterior fossa metastases in a 15-year-old male patient. The involvement of the third ventricular floor and nonthickened inferior pituitary stalk of the suprasellar lesion suggest that it is a metastasis of a primary pineal lesion rather than a dual-primary. This distinction, with the presence of posterior fossa metastases, favors the use of more aggressive treatment with combination radiation therapy and chemotherapy for a better outcome.

Endoscopic aqueductal membrane fenestration was effective for intractable hydrocephalus after removal of a nongerminomatous germ cell tumor exhibiting growing teratoma syndrome: a case report

BACKGROUND

Primary central nervous system (CNS) germ cell tumors (GCTs) are rare neoplasms predominantly observed in the pediatric and young adult populations. A mixed GCT including immature teratoma exhibiting growing teratoma syndrome is presented. The pathogenesis of growing teratoma syndrome remains unclear, and its treatment strategy has not been established. GCTs are often located within the ventricles, causing hydrocephalus, which sometimes improves after removal of the tumor due to restoration of cerebrospinal fluid (CSF) flow. On the other hand, even if the flow route of CSF from the third ventricle to arachnoid granulations on the brain surface quadrigeminal cistern is restored after removal of the tumor, hydrocephalus may not improve.

CASE PRESENTATION

A case whose intractable hydrocephalus improved after penetrating the aqueductal membrane via endoscopy is described. An 11-year-old boy was treated for pineal intracranial growing teratoma syndrome (IGTS). The tumor grew rapidly in a short period, and hydrocephalus progressed despite endoscopic third ventriculostomy (ETV). Although the obstruction was removed by radiation, chemotherapy, and total tumor resection, the hydrocephalus did not improve. Endoscopic membrane perforation was performed because a membrane-like structure was seen at the entrance of the cerebral aqueduct on magnetic resonance imaging. The hydrocephalus improved immediately after the operation, and the patient's consciousness disturbance also improved significantly.

CONCLUSION

The purpose of this report is to update the current knowledge and standards of management for patients with growing teratoma syndrome, as well as to drive future translational and clinical studies by recognizing the unmet needs concerning hydrocephalus.

Genomic characterization of intracranial teratomas using whole genome sequencing

Background

Intracranial teratoma is a rare neoplasm of the central nervous system, often classified into mature and immature types and occurs mainly in children and adolescents. To date, there has been no comprehensive genomic characterization analysis of teratoma due to its rarity of the cases.

Methods

Forty-six patients with intracranial teratomas were collected and 22 of them underwent whole-exome sequencing, including 8 mature teratomas and 14 immature teratomas. A comprehensive analysis was performed to analyze somatic mutations, copy number variants (CNVs), mutational signatures, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway in our cohort.

Results

The most common somatic mutated gene in intracranial teratomas was CARD11 (18%) and IRS1 (18%), followed by PSMD11, RELN, RRAS2, SMC1A, SYNE1 and ZFHX3, with mutation rates of 14% for the latter six genes. Copy number variation was dominated by amplification, among which ARAF (50%), ATP2B3 (41%), GATA1 (41%), ATP6AP1 (36%), CCND2 (36%) and ZMYM3 (36%) were the most frequently amplified genes. Copy number deletion of SETDB2 and IL2 only appeared in immature teratoma (43% and 36%, respectively), but not in mature teratoma (p = 0.051 and 0.115, respectively). Prognostic analysis showed that TP53 mutations might be associated with poor prognosis of intracranial teratomas patients.

Conclusions

Our study revealed the genetic characteristics of intracranial teratoma which might be valuable for guiding future targeted therapies.

Multiparametric Framework Magnetic Resonance Imaging Assessment of Subtypes of Intracranial Germ Cell Tumors Using Susceptibility Weighted Imaging, Diffusion-Weighted Imaging, and Dynamic Susceptibility-Contrast Perfusion-Weighted Imaging Combined With Conventional Magnetic Resonance Imaging

BACKGROUND

Intracranial germ cell tumors (iGCTs) are classified into two pathological subtypes (germinomas [GEs] and nongerminomatous germ cell tumors [NGGCTs]), with distinct treatment strategy and prognosis. Accurate preoperative determination of iGCT subtypes is essential to guide clinical decision-making and prognosis assessment.

PURPOSE

To investigate the diagnostic value of diffusion-weighted imaging (DWI), susceptibility weighted imaging (SWI), and dynamic susceptibility-contrast perfusion-weighted imaging (DSC-PWI) combined with conventional magnetic resonance imaging (cMRI) in finding subtypes of iGCTs.

STUDY TYPE

Retrospective.

POPULATION

A total of 40 patients (45% male and 55% female) with iGCTs.

FIELD STRENGTH/SEQUENCE

A 3 T; &lt;T1WI, T2WI, T1WI + C, DWI, SWI, DSC-PWI&gt;.

ASSESSMENT

The parameters of DWI and DSC-PWI were calculated based on extracted parameters of multiparametric MRIs. The characteristics of SWI and cMRI were also compared in GEs and NGGCTs.

STATISTICAL TESTS

The diagnostic efficacy of the minimum apparent diffusion coefficient (ADCmin), time-to-peak (TTP), relative mean transit time (rMTT), relative cerebral blood flow (rCBF), relative cerebral blood volume (rCBV) maps, and cMRI features in iGCT classification was evaluated by receiver operating characteristic curve (ROC) analyses. We calculated the sensitivity, specificity, AUC, and Youden index of the hybrid MR evaluation methods. A prospective cohort (five GEs and five NGGCTs) was designed as a simulation set to test the model. The significance threshold was set at P &lt; 0.01.

RESULTS

The ADCmin (1039.100 ± 453.830 vs. 1400.050 ± 394.650), rCBF values (20.650 ± 6.260 vs. 51.170 ± 6.570), and TTP values (24.450 ± 3.160 vs. 28.950 ± 5.120) were significantly lower in GEs than in NGGCTs. The combination of ADCmin, DSC-PWI, and cMRI showed the heights AUC (AUC = 0.962). The iGCT multiparametric framework showed the AUC was 0.958 in the simulation set.

DATA CONCLUSION

The iCGT multiparametric framework might be an effective diagnostic approach of iGCT subtype. The application of cMRI (T1WI, T2WI, and Gd-T1WI) with advanced imaging modalities (DWI, SWI, and PWI) had the best performance for classifying iGCT subtypes.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Multi-institutional analysis of central nervous system germ cell tumors in patients with Down syndrome

PURPOSE

Primary germ cell tumors (GCTs) are the most common central nervous system (CNS) neoplasm in patients with Down syndrome (DS). However, a standard of care has not been established due to paucity of data.

METHODS

A retrospective multi-institutional analysis was conducted, in addition to a comprehensive review of the literature.

RESULTS

Ten patients from six institutions (five USA, one Brazil) were identified, in addition to 31 patients in the literature from 1975 to 2021. Of the 41 total patients (mean age 9.9 years; 61% male), 16 (39%) had non-germinomatous germ cell tumors (NGGCTs), 16 (39%) had pure germinomas, and eight (19.5%) had teratomas. Basal ganglia was the most common tumor location (n = 13; 31.7%), followed by posterior fossa (n = 7; 17%). Nine patients (22%) experienced disease relapse or progression, of which four died from tumor progression (one germinoma, three teratomas). Sixteen patients (39%) experienced treatment-related complications, of which eight (50%) died (five germinomas, three NGGCTs). Of the germinoma patients, two died from chemotherapy-related sepsis, one from postsurgery cardiopulmonary failure, one from pneumonia, and one from moyamoya following radiation therapy (RT). Of the NGGCT patients, one died from chemotherapy-related sepsis, one from postsurgical infection, and one from pneumonia following surgery/chemotherapy/RT. Three-year overall survival was 66% for all histological types: 62% germinomas, 79% for NGGCTs, and 53% for teratomas.

CONCLUSION

Patients with DS treated for CNS GCTs are at an increased risk of treatment-related adverse events. A different therapeutic approach may need to be considered to mitigate treatment-related complications and long-term neurocognitive sequelae.

Pathogenesis of central nervous system germ cell tumors

Intracranial germ cell tumors (IGCTs) are clinically rare. They are more common in children and adolescents and the incidence in Asia is higher than in Western countries. Histologically, IGCTs are divided into germinoma and non-germinomatous germ cell tumor (NGGCT). Germinoma is sensitive to radiotherapy and chemotherapy and therefore, patients with germinoma have a good prognosis. However, NGGCTs, especially those with malignant components, are not sensitive to radiotherapy and chemoradiotherapy, leading to a poor prognosis. The pathogenesis of IGCTs is not fully understood. By summarizing previous literature, we found that the occurrence of IGCTs may be related to the following factors: chromosomal instability, MAPK and/or PI3K pathway changes, and DNA hypomethylation in pure germ cell tumors.

Successful management of symptomatic hydrocephalus using a temporary external ventricular drain with or without endoscopic third ventriculostomy in pediatric patients with germinoma

OBJECTIVE

The objective of this study was to describe the management of hydrocephalus in a cohort of pediatric patients with germinoma.

METHODS

The authors conducted a retrospective chart review of patients with germinoma and symptomatic hydrocephalus treated at the Hospital for Sick Children between 2002 and 2020. Descriptive data included tumor location, CSF diversion procedure (external ventricular drain [EVD], endoscopic third ventriculostomy [ETV], ventriculoperitoneal [VP] shunt) and outcomes. The frontooccipital horn ratio (FOR) method was used to determine the presence of ventriculomegaly.

RESULTS

Of 39 patients with germinoma, 22 (73% male) had symptomatic hydrocephalus at diagnosis (11 pineal, 4 suprasellar, and 7 bifocal). Management of hydrocephalus included EVD (n = 5, 22.7%), ETV (n = 5, 22.7%), and combination ETV and EVD (n = 7, 31.8%), whereas 5 patients (22.7%) did not undergo surgical intervention. The median FOR at diagnosis was 0.42 (range 0.38-0.58), which correlated with moderate to severe ventriculomegaly. Carboplatin and etoposide-based chemotherapy induced fast tumor shrinkage, avoiding CSF diversion (n = 5) and resolving hydrocephalus with a transient EVD (n = 5). The median duration until EVD removal was 7 days (range 2-10 days). Two of 12 patients with EVD ultimately required a VP shunt. Kaplan-Meier overall survival was 100% and progression-free survival was 96.4% at a median follow-up of 10.4 years.

CONCLUSIONS

Timely initiation of chemotherapy is imperative to rapidly reduce tumor bulk in children with germinoma and limits the need for VP shunt insertions. In children in whom CSF diversion is required, hydrocephalus may be successfully managed with a temporary EVD ± ETV.

Photon versus proton whole ventricular radiotherapy for non-germinomatous germ cell tumors: A report from the Children's Oncology Group

PURPOSE

To determine if proton therapy reduces doses to cranial organs at risk (OARs) as compared to photon therapy in children with non-germinomatous germ cell tumors (NGGCT) receiving whole ventricular radiotherapy (WVRT).

METHODS AND MATERIALS

Dosimetric data for patients with NGGCT prospectively enrolled in stratum 1 of the Children's Oncology Group study ACNS1123 who received 30.6 Gy WVRT were compared. Target segmentation was standardized using a contouring atlas. Doses to cranial OARs were compared between proton and photon treatments. Clinically relevant dose-volume parameters that were analyzed included mean dose and dose to 40% of the OAR volume (D40).

RESULTS

Mean and D40 doses to the supratentorial brain, cerebellum, and bilateral temporal, parietal, and frontal lobes were statistically significantly lower amongst proton-treated patients, as compared to photon-treated patients. In a subgroup analysis of patients uniformly treated with a 3-mm planning target volume, patients who received proton therapy continued to have statistically significantly lower doses to brain OARs.

CONCLUSIONS

Children treated with proton therapy for WVRT had lower doses to normal brain structures, when compared to those treated with photon therapy. Proton therapy should be considered for patients receiving WVRT for NGGCT.

Mediastinal metastases from a primary immature teratoma of the CNS

Primary intracranial germ cell tumors are rare, occurring more frequently in children and young adults in midline locations of the brain. Teratomas are an uncommon variant of germ cell neoplasm, although they account for a high proportion of fetal brain tumors. Here, we report a 27-year-old male who presented with a heterogeneously enhancing lesion in the left thalamus, without evidence of systemic disease. Histologic and immunohistochemical analysis were consistent with immature teratoma; next-generation sequencing was negative for targetable molecular alterations. The patient received chemotherapy and radiotherapy post-excision. Following the initial resection, ventriculoperitoneal shunt placement was performed due to left temporal horn entrapment. Nine months later, imaging revealed mediastinal and hilar adenopathy as well as pleural disease, with encasement and compression of pulmonary vasculature, and multiple, bilateral pulmonary nodules. Fine needle aspiration showed malignant cells with an immunohistochemical profile similar to the original tumor, consistent with metastases. Though germ cell tumors are known to spread via cerebrospinal fluid or blood, metastasis outside of the CNS from a primary intracranial germ cell tumor is a rare complication. Spread via ventriculoperitoneal shunt, which may have occurred in the present case, has also rarely been observed.

The Effects of Methanol Extracts of Hyssopus officinalis on Model of Induced Glioblastoma Multiforme (GBM) in Rats

Given the complexity of pathophysiological processes of brain tumors, ineffective therapies, and high mortality rate, new therapeutic options with less toxicity are necessary. Hyssopus officinalis (hyssop) is an aromatic plant with important biological activities. The aim of this study is to assess the anti-cancer effect of hyssop extract on damages of glioblastoma multiforme. In this study, total flavonoids, phenolic content, and quantification of phenolic compound of hyssop extracts were analyzed. In vitro antioxidant properties of hyssop extract were also examined. In addition, cell viability, apoptosis, and cell cycle were evaluated in C6 glioma cell culture. In vivo, the rats were divided randomly into four main groups: intact, control, vehicle, and treatment groups. 1 × 106 C6 rat glioma cells were implanted into the right caudate nucleus of the rat's brain. The treatment group received the methanol extract of hyssop (100 mg/kg) for 7 days. Evolution of locomotor activity, tumor volume, survival rate, activities of antioxidant enzymes (superoxide dismutase (SOD) and catalase (CAT)), vascular endothelial growth factor (VEGF) expression, TUNEL-positive cells, p53 and p21 mRNA expression, and histological alterations were performed. The results showed that the methanol extract of hyssop increased the apoptosis and reduced the cell division of C6 glioma cells in cell culture. Moreover, methanol extract decreased the tumor volume and prolonged survival. Also, the activity of SOD and CAT enzymes was reduced in tumor tissue and enhanced in surrounding tissue. TUNEL-positive cells were increased in methanol extract of hyssop group. The expression of p53 and p21 mRNA was upregulated in the treatment group. Moreover, the histological analysis indicated a considerable decrease in invasion of tumor cells and inflammation in the hyssop-treated rats. According to the achieved results, it can be stated that hyssop has sufficient potential to inhibit damage of brain tumors, at least in part, by affecting the oxidative stress and cell proliferation pathways.

Outcomes of intracranial non-germinomatous germ cell tumors: a retrospective Asian multinational study on treatment strategies and prognostic factors

PURPOSE

Non-germinomatous germ cell tumors (NGGCTs) are rare pediatric conditions. This multicenter study using Asian multinational patient data investigated treatment outcomes and prognostic factors for NGGCTs.

METHODS

Medical records of 251 patients with NGGCTs treated from 1995 to 2015 were retrospectively analyzed from participating centers in Asian countries (Korea, Taiwan, Singapore, and Japan).

RESULTS

The median follow up was 8.5 years (95% CI 7.8-9.9). In the total cohort, 5-year event-free survival (EFS) and overall survival (OS) rates were 78.2% and 85.4%, respectively. In 17.9% of the patients, diagnosis was determined by tumor markers alone (alpha-fetoprotein ≥ 10 ng/mL (Korea) or > 25 ng/mL (Taiwan and Singapore), and/or β-human chorionic gonadotropin (β-hCG) ≥ 50 mIU/mL). Patients with immature teratomas and mature teratomas comprised 12.0% and 8.4%, respectively. The 5-year EFS rate was higher in patients with histologically confirmed germinoma with elevated β-hCG (n = 28) than those in patients with malignant NGGCTs (n = 127). Among malignant NGGCTs, patients with choriocarcinoma showed the highest 5-year OS of 87.6%, while yolk sac tumors showed the lowest OS (68.8%). For malignant NGGCT subgroups, an increase in serum β-hCG levels by 100 mIU/mL was identified as a significant prognostic factor associated with the EFS and OS.

CONCLUSION

Our result shows excellent survival outcomes of overall CNS NGGCT. However, treatment outcome varied widely across the histopathologic subgroup of NGGCT. Hence, this study suggests the necessity for accurate diagnosis by surgical biopsy and further optimization of diagnosis and treatment according to the histopathology of NGGCTs. Future clinical trials should be designed for individualized treatments for different NGGCTs subsets.

Basal Ganglia Germinoma in an Adolescent: A Case Report

Germ cell tumors are rare tumors and may pose a diagnostic dilemma. We present a 15-year-old boy with insidious onset right hemiparesis followed by polyuria and polydipsia. Later, he also developed cognitive decline and speech disturbances. Serial magnetic resonance images (MRIs) over a 2-year period showed progressive atrophy of the left caudate nucleus, along with Wallerian degeneration of the left internal capsule and crus of midbrain. Further in the course, imaging revealed an ill-defined signal intensity involving left ganglio-capsulo-thalamic region with increased perfusion which was suggestive of basal ganglia germinoma. Beta human chorionic gonadotropin levels were mildly elevated. This case illustrates an uncommon presentation of a central nervous system germinoma which is often misdiagnosed in the early stages because of its atypical symptomatology and MRI findings.

An international study evaluating the epidemiology of intracranial germ cell tumors in the native versus immigrant Japanese populations: the need for an international registry

BACKGROUND

Pediatric intra-cranial germ cell tumors (iGCTs) occur at an incidence of 0.6-1.2 cases/million/year in Western countries. The incidence is reported up to 5 times higher in Japan. It is unknown whether this increased incidence is due to genetic predisposition or environment.

METHODS

The incidence of iGCTs in children ages 0-19 years was evaluated from December 1st, 1996-December 1st, 2016 in stable Japanese immigrant populations living abroad and compared to current native Japanese registry data. The incidence of medullobblastoma was used as a control to account for assumptions in the data. Sites were identified based on historical and population data of known large scale emigration from Japan during a period of industrialization from 1868-1912 which resulted in large, stable Japanese immigrant populations abroad. These three representative sites included Lima, Peru, San Paolo, Brazil, and Vancouver, Canada. Data was collected from registry and hospital-based resources within each region.

RESULTS

A review of the Brain Tumor Registry of Japan from 1984-2004 revealed an incidence of 2.5 cases/million/year, lower than previously reported, and a lower incidence of medulloblastoma at 1.2 cases/million/year. Data from Vancouver, Canada, Lima, Peru, and San Paolo, Brazil included a total population of 731,174 Japanese persons. The ratio of all medulloblastoma to iGCT cases in Japan was identified as 1:2 while the ratio was 2:1, 6.5:1, and 5:1, respectively, in the other three locations. The data suggests increased incidence in native Japan may not translate to higher incidence in immigrant Japanese populations abroad and a clear genetic component was not found in our data set.

CONCLUSIONS

A more precise and comprehensive study is needed to determine the cause of this difference in incidence. This study also emphasizes the importance of national and state registries and is a call to collaborate on state and country level epidemiology studies.

Radiological Latency in Pineal Germinoma: A Case Report and Literature Review

Suprasellar germinomas can present with non-diagnostic, or even normal results on imaging. The spectrum of reported cases ranges from normal imaging, thickened pituitary stalks, to discrete tumour growths. This similar phenomenon is less commonly seen in the pineal region, or bifocal germinomas, and the literature is sparse with only a few case series or reports mentioning a similar presentation of signs and symptoms preceding radiological evidence of diagnosis. We report a case of pineal germinoma presenting with dorsal midbrain syndrome with no evidence of tumour growth on initial imaging despite symptoms. For patients presenting with this clinical radiological latent period, follow-up imaging is useful to identify interval development of germinomas. This applies to patients with dorsal midbrain syndrome, or even other unexplained ophthalmoplegia, as the initial sign of pineal region germinoma, despite normal imaging.

Evaluation of the Perioperative and Postoperative Course of Surgery for Pineal Germinoma in the SIOP CNS GCT 96 Trial

Background: CNS germinoma, being marker-negative, are mainly diagnosed by histological examination. These tumors predominantly appear in the suprasellar and/or pineal region. In contrast to the suprasellar region, where biopsy is the standard procedure in case of a suspected germ-cell tumor to avoid mutilation to the endocrine structures, pineal tumors are more accessible to primary resection. We evaluated the perioperative course of patients with pineal germinoma who were diagnosed by primary biopsy or resection in the SIOP CNS GCT 96 trial. Methods: Overall, 235 patients had germinoma, with pineal localization in 113. The relationship between initial symptoms, tumor size, and postoperative complications was analyzed. Results: Of 111 evaluable patients, initial symptoms were headache (n = 98), hydrocephalus (n = 93), double vision (n = 62), Parinaud syndrome (n = 57), and papilledema (n = 44). There was no significant relationship between tumor size and primary symptoms. A total of 57 patients underwent primary resection and 54 underwent biopsy. Postoperative complications were reported in 43.2% of patients after resection and in 11.4% after biopsy (p < 0.008). Biopsy was significantly more commonly performed on larger tumors (p= 0.002). Conclusions: These results support the practice of biopsy over resection for histological confirmation of pineal germinoma.