Primary CNS germ cell tumors: current epidemiology and update on treatment

Suprasellar teratoma to germinoma recurrence: implications for diagnosis and follow-up

Mature teratoma is a subtype of intracranial germ cell tumors (GCTs), distinguished from malignant GCTs by its benign nature and excellent prognosis. Typically, no adjuvant therapy is recommended following gross total resection (GTR). We report a case of a prepubertal girl with a suprasellar mature teratoma that recurred as a germinoma 6 months post-GTR. A 7-year-old girl presented with headache and polydipsia. Imaging revealed a suprasellar mass. The patient underwent GTR, and pathological diagnosis confirmed a mature teratoma without other GCT components. Six months later, MRI identified a newly developed suprasellar mass adjacent to the optic chiasm. A second surgery confirmed the mass as a germinoma. The patient subsequently underwent adjuvant chemotherapy combined with proton therapy, resulting in complete remission. The diagnosis of mature teratoma must be approached with caution, and thorough follow-up is imperative, particularly in cases involving female patients, prepubertal age, or non-pineal locations.

The role of neurosurgeon in the multidisciplinary approach to ectopic or bifocal intracranial germinoma: A systematic review and report of two illustrative cases

BACKGROUND

Pure germinoma typically originates from the midline and is usually found in the pineal and suprasellar regions in 76-90 % of cases. When it is in both regions, it is considered bifocal (10 % at diagnosis). If pure germinoma is located outside of the midline, it is considered ectopic, with a global incidence of about 0.7 %. The study aims to describe the clinical and surgical approach to patients with atypical intracranial ectopic germinoma (IEG) and bifocal germinoma (BG) through a literature review with the goal to delineate the correct diagnostic and therapeutic pathway, to reduce the diagnostic delay and improve the prognosis of these patients.

METHODS

A systematic review of the literature in most common electronic database (PubMed, Ovid MEDLINE and Ovid EMBASE) on IEG and BG, in according with the "PRISMA statement" criteria, from January 1990 to September 2022 was done. In addition, two rare cases of IEG and BG were reported.

RESULTS

This systematic review included 16 papers (20 patients) with a final diagnosis of IEG and 30 papers (121 patients) with a final diagnosis of BG. IEGs seems to involve primary basal ganglia (40 %) and corpus callosum (40 %). For IEGs, biopsy (70 %, 14 cases out of 20) was the most common surgical approach: open approach (35 %), stereotactic minimally invasive approach (30 %) or endoscopic trans-sphenoidal approach (5 %). Partial resection was performed in 10 % of cases, whereas a total resection was performed in 20 % of cases. Also for BGs, biopsy was the most common surgical approach in 80 % of patients, whereas surgical resection (partial or total) was performed in 5.3 % of patients.

CONCLUSION

IEG and BG are rare type of primary intracranial germ cell tumor, whose unusual location often can cause delays in diagnosis, which can have a significant impact on the patient's prognosis and requiring a multidisciplinary and timely approach.

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.

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.

Hemophagocytic lymphohistiocytosis during treatment of intracranial multifocal germinoma: a case report and literature review

Hemophagocytic lymphohistiocytosis (HLH), also known as hemophagocytic syndrome (HPS), is a benign histiocytosis with hyperreactive proliferation of the mononuclear phagocyte system caused by immune function abnormalities, which often occurs under the background of genetic mutations, inflammation, infection or tumors. Because the research on malignancy-associated HLH (M-HLH) is focused on hematological malignancies, reports on HLH secondary to solid tumors are rare. In this case, we report a 14-year-old girl who developed HLH during treatment for intracranial multifocal germinoma, and the disease was controlled after hormone combined with etoposide(VP-16) and other related treatments. To our knowledge, there have been no documented cases of HLH caused by intracranial multifocal germinoma.

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.

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.

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; <T1WI, T2WI, T1WI + C, DWI, SWI, DSC-PWI>.

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 < 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.

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.

Mission impossible: chemotherapy in the intensive care for pineal region germ cell tumor

Pineal region tumors are rare and a heterogenous group of primary central nervous system tumors which are primarily classified as germ cell tumors and non-germ cell tumors. Chemotherapy and radiotherapy as the primary treatment modalities have been reported to result in good outcomes. We discuss the case of a young girl who presented to our emergency department in an unconscious state and had a large lesion in the posterior third ventricular region, but without any associated hydrocephalus which could explain her stuporous state. Given the rapid decline in her sensorium, we were faced with the difficult choice between surgical decompression of the tumor and a trial of rescue chemotherapy following histopathological confirmation through biopsy. She underwent an open biopsy followed by chemotherapy in a neurosurgical intensive care unit despite her poor Karnofsky performance score. She improved after chemotherapy and her tumor decreased in size significantly over time. We highlight the role of chemotherapy administered in the neurosurgical ICU to an unconscious patient with a large chemoresponsive tumor leading to rapid shrinkage of the lesion and gradual improvement in the sensorium of the patient.

Cerebrospinal Fluid Levels of AFP and hCG: Validation of the Analytical Method and Application in the Diagnosis of Central Nervous System Germ Cell Tumors

The determination of Human Chorionic Gonadotropin (hCG) and Alpha Fetoprotein (AFP) levels on serum and amniotic fluid plays a fundamental role in the diagnosis and follow-up of specific physiological or pathological conditions (e.g., pregnancy, threat of abortion or germ cell tumors). Recently, the quantification of hCG and AFP in other biological fluids has gained great attention to support the diagnosis, prognosis and follow-up of neoplastic diseases deriving from trophoblastic cells, such as germinomas. Most of the commercial kits for hCG and AFP assays are developed to be used on biological fluids such as serum/plasma and/or urine by manufacturing companies. The aim of this work was to evaluate the suitability of the analytical method certified for the use on serum, and/or amniotic fluid for the quantification of hCG and AFP in cerebrospinal fluid, carrying out an internal validation protocol. The data reported here show that the automated immunochemical method is fit for quantification of hCG and AFP in cerebrospinal fluid (CSF), allowing selective and specific diagnosis of secreting germ cell tumors. This is confirmed by the positive correlation between elevated levels of hCG or AFP and the diagnosis of brain tumors.

Gray matter structural plasticity in patients with basal ganglia germ cell tumors: A voxel-based morphometry study

BACKGROUND

Basal ganglia germ cell tumors (BGGCTs) are rare intracranial germ cell tumors (iGCTs) that often presents with cognitive impairment.

OBJECTIVE

To assess structural brain plasticity in the presence of unilateral basal ganglia germ cell tumors (BGGCTs), and the correlation between gray matter volume (GMV) changes and cognitive tests.

MATERIALS AND METHODS

We applied voxel-based morphometry (VBM) to structural magnetic resonance imaging (MRI) scans to compare a sample of 41 patients with BGGCTs in the left (n = 22) or right (n = 19) and a sample of 16 patients as control group using a two-sample t-test, correcting for family-wise-errors. A battery of cognitive tests was administered to all BGGCTs patients prior to MRI. We used Pearson correlation analysis to assess the correlation between cognitive test scores and GMV changes.

RESULTS

In patients with left BGGCTs, whole-brain VBM analysis revealed a large cluster of voxels reflecting an increase in GMV in the left parahippocampal region (k = 529 voxels, T = 4.18, p < 0.01), right middle cingulate cortex (k = 172 voxels, T = 3.96, p < 0.01), and a decrease in volume in the left thalamus (k = 527 voxels, T = -4.88, p < 0.01), right inferior frontal gyrus (k = 495 voxels, T = -4.29, p < 0.01). Pearson correlation analysis showed that the GMV were significantly correlated with the Integrated Visual and Auditory continuous performance test (IVA-CPT) scale (r = 0.637, P = 0.002), abstract reasoning (r = 0.597, P = 0.011), Self-rating Depression Scale (SAS) scale (r = -0.623, P = 0.004) and memory recall (r = 0.648, P = 0.003).

CONCLUSION

These results demonstrate that slow growing but destructive BGGCTs markedly and asymmetrically effect the GMV in left parahippocampal, left thalamus, right middle cingulate cortex, right inferior frontal gyrus and GMV changes were significantly associated with cognitive test.

Incidence and outcomes of malignant ovarian germ cell tumors in Korea, 1999-2017

OBJECTIVE

Malignant ovarian germ cell tumor (MOGCT) is a rare ovarian malignancy accounting for less than 5% of all ovarian cancers. We aimed to evaluate the incidence, survival, and subsequent malignancies after the diagnosis of MOGCT.

METHODS

Data from the Korea Central Cancer Registry were used to identify MOGCTs between 1999 and 2017. The age-standardized rates (ASRs), 5-year relative survival rates (RSR) and standardized incidence ratio (SIR) for subsequent cancer after diagnosis of MOGCT were estimated.

RESULTS

Of 2125 cases of newly diagnosed MOGCTs, 596 (28.0%) were diagnosed with dysgerminoma and 1529 (72.0%) with non-dysgerminoma. The ASR per 100,000 women-years was 0.539; ASR slightly increased over the study period (annual percent change [APC] = 1.01%; p = 0.02). There was an increase and decrease in the incidence of MOGCTs in the age groups 0-19 years (APC = 1.96%; p < 0.01) and ≥ 50 years (APC = -6.51%; p < 0.01), respectively. Patients with dysgerminoma showed significantly higher RSR than patients with non-dysgerminoma (98.0% vs. 94.9%, p < 0.01). Patients aged ≥50 years showed worst 5-year RSR (68.7%) than patients aged 0-19 years (97.8%) and 20-34 years (96.4%) (p < 0.01). The overall SIR for a subsequent cancer occurrence was 2.07, with the most frequent site of subsequent primary cancer being the thyroid (SIR = 2.78).

CONCLUSIONS

Our data demonstrated an excellent prognosis of MOGCTs among Korean women. There was a slight increase in MOGCT prevalence, which was more pronounced among those aged <19 years. After MOGCT diagnosis, the risk of developing a subsequent malignancy was doubled compared with the general population.

The clinical and imaging features of infratentorial germinomas compared with supratentorial ectopic germinomas

BACKGROUND

Intracranial germinoma is very sensitive to chemoradiotherapy, while the risk of infratentorial operation is high. The accurate diagnosis can provide the more reasonable treatment, avoiding the unnecessary therapeutic risks.

PURPOSE

To evaluate the clinical and imaging features of infratentorial germinomas.

MATERIAL AND METHODS

The clinical and imaging data of 13 infratentorial germinomas were collected and compared with 17 supratentorial germinomas in the same period. The clinical and imaging findings were retrospectively analyzed.

RESULTS

Infratentorial germinomas were more common in female patients than supratentorial ones (53.85% vs. 11.76%, P = 0.020). The mean age of the infratentorial group (23.0 ± 10.2 years) was significantly older than that of supratentorial group (12.4 ± 3.3 years, P = 0.003). Most infratentorial germinomas (12/13, 92.31%) underwent surgical resection, while stereotactic biopsy was more common in the supratentorial group (11/17, 64.71%, P = 0.002). Infratentorial germinomas were significantly smaller than supratentorial ones (25.85 ± 8.13 mm vs. 37.18 ± 18.11 mm, P = 0.031). Cystic lesions were more common in supratentorial germinomas (12/17, 70.59%), while most infratentorial germinomas were solid lesions (10/13, 76.92%, P = 0.025). On post-contrast T1-weighted imaging, obvious enhancement was more common in infratentorial germinomas than in supratentorial ones (100% vs. 64.71%, P = 0.024).

CONCLUSION

In addition to the common findings with supratentorial germinomas, infratentorial lesions have some specific clinical and imaging features.

Primary intracranial germ cell tumour originating from right brachium Pontis with hypertrophic Olivary degeneration: a case report

BACKGROUND

Primary right brachium pontis germinoma with hypertrophic olivary degeneration (HOD) is extremely rare. A preoperative diagnosis is challenging due to the absence of characterized clinical and neuroimaging features, and biopsy should be considered.

CASE PRESENTATION

A 20-year-old male patient presented with a case of primary intracranial germinoma originating from right brachium pontis with HOD manifesting as ocular myoclonus, nystagmus in both eyes, ataxic gait and incoordination of the limbs. Magnetic resonance imaging (MRI) revealed an irregular patchy lesion with hyperintensity on T2-weighted images (T2WI) and T2 fluid-attenuated inversion recovery (FLAIR) without enhancement by gadolinium (Gd). Furthermore, a focal hyperintense nodule on T2WI in the left inferior olive nucleus (ION) of the medulla oblongata was considered hypertrophic olivary degeneration (HOD) based on the patient's symptoms and neuroimaging findings. Due to suspected demyelinating disease and low-grade glioma (LGG), a biopsy was planned. The pathological diagnosis was germinoma. Subsequently, he received chemoradiation therapy, resulting in the improvement of neurological deficits and the disappearance of the lesion on MRI.

CONCLUSION

A case of "Primary right brachium pontis germinoma with HOD" is reported for the first time. A preoperative diagnosis is challenging due to the fact of absence of clinical signs and symptoms and neuroimaging characteristics. However, patients can have favourable prognoses with appropriate evaluation and treatment.

Co-existence of multiple sclerosis and germinoma in an adult male: Case report

Background

Concurrent diagnosis of multiple sclerosis (MS) and the central nervous system (CNS) germinoma is rare. The diagnostic criteria for MS rely primarily on clinical presentation, and CNS germinoma can present as an MS mimic. These factors contribute to the rarity of dual diagnosis.

Case Description

A 28-year-old man presented initially with bilateral optic neuritis, manifesting as persistently worsening vision for 2 years, and demyelinating plaques identified within the corpus callosum on magnetic resonance imaging. Initial work-up, in addition to clinical presentation, led to diagnosis of MS. Three months following the diagnosis of MS, the patient then presented with obstructive hydrocephalus due to a newly diagnosed intraventricular mass. The patient underwent an endoscopic third ventriculostomy and biopsy which confirmed diagnosis of CNS germinoma.

Conclusion

To the best of our knowledge, dual presentation of both MS and CNS germinoma has never been reported in the literature. The clinical presentation of bilateral optic neuritis (persisting for roughly 2 years before initial MS diagnosis), demyelinating plaques, and intrathecal oligoclonal bands before the development of an intraventricular mass indicates that both MS and CNS germinoma presented simultaneously in this patient. The treatment plan for this patient included carboplatin + etoposide, followed by adjuvant radiation and subsequent IVIG therapy.

Intracranial Germinoma Misdiagnosed as Hyperthyroidism: A Case Report and Review of the Literature

Intracranial germ cell tumors (GCTs) are relatively rare, which account for 0.5% of all primary intracranial neoplasms. Intracranial germinomas most commonly occur in the pineal and suprasellar region, making up the majority of all intracranial GCTs. For its diversified clinical manifestations, the diagnosis is easily confused with other diseases. Here, we present a case of a 19-year-old boy with intracranial germinoma who was preliminarily misdiagnosed as hyperthyroidism for the symptoms of weight loss and thyroid dysfunction.

Basal Ganglia Germ Cell Tumors With or Without Sellar Involvement: A Long-Term Follow-Up in a Single Medical Center and a Systematic Literature Review

BACKGROUND

Basal ganglia germ cell tumors (BGGCTs) represent an extremely rare subset of tumors about which little is known. Some patients suffer from tumor dissemination, such as sellar involvement. This study aimed to evaluate the independent prognostic risk factors of patients with BGGCTs with or without sellar involvement.

METHODS

Sixteen patients were diagnosed with BGGCTs at Peking Union Medical College Hospital from January 2000 to December 2020. A literature review was performed on the online databases Medline and PubMed, and 76 cases in the 19 retrieved articles were identified at the same time. The data regarding biochemical tests, radiological examinations, and outcomes during follow-up were analyzed.

RESULTS

Of 92 patients in this study, seven patients were clinically diagnosed as germinomas, with the remaining 85 patients receiving surgery. Fifty-two patients suffered from multifocal lesions or tumor dissemination. The patients with BGGCTs demonstrated a significant male predilection. The patients with delayed diagnosis more likely had cognitive disturbance (p = 0.028), mental disturbance (p = 0.047), and diabetes insipidus (p = 0.02). Multivariate analysis demonstrated that the independent poor prognostic risk factors of patients with BGGCTs were delayed diagnosis [odd ratio (OR) 2.33; 95% CI 1.02-5.31], focal radiotherapy (OR 4.00; 95% CI 1.69-9.49), and non-pure germinoma (OR 4.64; 95% CI 1.76-12.22).

CONCLUSIONS

The delayed diagnosis, focal radiotherapy, and non-pure germinoma were associated with a poorer prognosis for patients with BGGCTs with or without sellar involvement.

A Rare Case of Atypical Pleomorphic Neoplasm of Pineal Region in a Child: A Case Report

A 10-year-old boy with no past medical history presented with complaints of nausea and vomiting associated with morning headache for the last month. Ophthalmic nerve and eye exam showed diplopia and strabismus with no other significant findings on physical and neurological examination. Magnetic resonance imaging (MRI) of the brain revealed a homogenous hyperdense and enhancing mass in the pineal region. The endoscopic biopsy of the pineal region demonstrated the cells with highly pleomorphic and hyperchromatic nuclei with an increase in mitotic activity. There were many vessels but no area of vascular proliferation and necrosis. Granular bodies with eosinophilia were identified. Immunohistochemistry was positive for class III b-tubulin with epidermal growth factor receptor (EGFR) staining and glial fibrillary acidic protein (GFAP). Immunostaining was positive for p53, Phosphatase and Tensin homolog (PTEN), and oligodendrocyte transcription factor (OLIG2), while staining for cluster of differentiation (CD)34, cytokeratin (CK), human melanoma black (HMB)45, and isocitrate dehydrogenase (IDH)-R132H mutation was negative, consistent with atypical pleomorphic neoplasm of the pineal region. The patient underwent tumor resection via a sub-occipital trans-tentorial approach, followed by one dose of chemotherapy. The patient experienced a resolution of the symptom and was doing well on his bi-monthly follow up. 

Treatment outcomes based on radiation therapy fields for bifocal germinoma: Synchronous or disseminated disease?

Intracranial germinoma sometimes present as bifocal germinoma, and whether bifocal germinoma should be treated as a synchronous or disseminated disease remains unclear. This study aimed to determine the optimal treatment modality for bifocal germinoma. Patients with bifocal germinoma who received radiotherapy (RT) from March 1990 to August 2017 were included for analysis. A total of 21 patients were included. The median follow-up period was 76.2 months (range, 6.2-305.4 months). There were 17 patients who received cranio-spinal irradiation (CSI) with local RT; 3, whole ventricular RT (WVRT) with local RT; and 1, local RT only. Three recurrences occurred (1 patient each among those who underwent CSI, WVRT, and local RT). Recurrence in the patient who received CSI and who received WVRT occurred in the right thalamus and right frontal convexity, respectively. Meanwhile, the patient who received local RT showed not only a recurred lesion in the hypothalamus, but also cerebrospinal fluid seeding. For this patient, salvage CSI was performed and complete response was achieved after treatment. However, after 9 years and 6 months, he was diagnosed with glioblastoma and expired. As for toxicity, although 17 patients showed decrease in complete blood count levels during treatment, all patients recovered soon after treatment completion. Our findings suggest that bifocal germinoma may be considered as a disseminated disease when considering the patterns of failure according to RT fields. In addition, patients who received CSI showed low acute toxicity rates. However, further studies are necessary to confirm these findings.

Clinical features, radiologic findings, and treatment of pediatric germ cell tumors involving the basal ganglia and thalamus: a retrospective series of 15 cases at a single center

PURPOSE

Pediatric germ cell tumors (GCTs) involving the basal ganglia and thalamus are relatively rare neoplasms which have not been extensively described. We here summarize the clinical and radiological features of a series of such tumors and discuss optimal treatment strategies based upon our experience.

METHODS

A total of 15 pediatric patients with basal ganglionic and thalamic GCTs were treated between 2011 and 2016 at West China Hospital. Epidemiological characteristics, clinical features, imaging findings, and treatment strategies were reviewed retrospectively.

RESULTS

GCTs constituted 28% (15/53) of pediatric basal ganglionic and thalamic tumors in our institution between 2011 and 2016. There were 12 males and 3 females with mean age of 11.7 ± 2.8 years (range, 7-16 years). The most common initial manifestation was hemiparesis (n = 13, 86.7%), followed by headache (n = 5, 33.3%), vomiting (n = 3, 20.0%), cognitive disturbance (n = 2, 13.3%), and seizure (n = 1, 6.7%). No tumors were incidentally detected. The mean duration of the symptoms before diagnosis was 4.4 ± 3.9 months (range from 9 days to 13 months). The maximum diameters of the lesions ranged from 3.2 to 6.5 cm (mean 4.7 ± 1.1 cm). Cysts were seen in tumors in MRIs in 11 patients (73%), intratumoral hemorrhages in 3 (20%), calcification in 2 (13%), and there was obstructive hydrocephalus in 1 (7%). Of note, hemiatrophy was observed in 9 cases (60.0%). The mean follow-up for the 15 patients was 28 months (range, 9-54 months), and no patients were lost. During the follow-up period, all patients (9 cases) with germinomas responded well to radiotherapy, and no recurrence was observed. Among 4 patients with mixed nongerminomatous germ cell tumor, 2 suffered tumor recurrence after treatment. Neurological deficits improved or remained unchanged in 12 patients but 3 developed new dysfunction including significant cognitive disturbance and hemiparesis.

CONCLUSIONS

Pediatric GCTs in the basal ganglia and thalamus are not as rare as previously considered. Tumor markers should be tested routinely for tumors in these sites in young patients. Optimal treatment strategy based on accurate diagnosis and comprehensive clinical assessment should be recommended.

Adolescents and young adults with brain tumors in the context of molecular advances in neuro-oncology

Adolescents and young adults (AYA) comprise a specific group of oncology patients with a distinct biological and epidemiological spectrum of central nervous system neoplasms. It has been well documented that they differ clinically, especially in relation to prognosis and chemotherapy tolerance; however, the underlying reasons for this are unclear. Recent advances in the genomics of both childhood and adult brain tumors have provided new explanations and insights into the previously described age-dependent heterogeneity. Herein, we summarize the current state of the AYA population in neuro-oncology, specifically how biological advances can help personalize therapy for this unique group of patients.

Treatment of primary intracranial germ cell tumors: Single center experience with 42 clinically diagnosed cases

Background and Objective

Primary intracranial germ cell tumors (GCTs) are a class of heterogeneous tumors. Surgery can quickly relieve tumor compression and provide histological diagnosis. It is very difficult to treat some patients who are unable to be pathologically diagnosed. We aimed to analyze clinically diagnosed GCTs patients.

Methods

Patients clinically diagnosed as primary intracranial GCTs were included in this study.

Results

From 2002 to 2015, 42 patients clinically diagnosed with primary intracranial GCTs received chemotherapy and/or radiotherapy. Patients were assigned to diagnostic chemotherapy group (25 cases), diagnostic radiotherapy group (5 cases) and gamma knife radiosurgery group (12 cases) based on their initial anti-tumor therapy. The 5-year survival rates were 85.8%, 75.0% and 63.6%, respectively. There were no statistically significant difference (p value = 0.44). Patients were assigned to the group (30 cases) with secretory tumors and the group (12 cases) with non-secretory tumors based on their levels of tumor makers. The 5- year survival rates were 80.7% and 68.6%, respectively. There were no statistically significant difference (p value = 0.49).The major adverse reactions were grade III - IV bone marrow suppression with an incidence of 35.2% and grade II- III nausea/vomiting with an incidence of 45.8%.

Conclusion

Surgical removal of tumor or biopsy is recognized as the most accurate method to determine the pathological property of tumor. But for some patients who can not be pathologically diagnosed, they can receive comprehensive treatments such as chemotherapy combined with radiotherapy, and some of them can still have good responses.

Incidental primary mediastinal choriocarcinoma diagnosed by endobronchial ultrasound-guided fine needle aspiration in a patient presenting with transient ischemic attack and stroke

We describe a case of a 41-year old male patient with no significant prior medical history who presents with symptoms of Transient Ischemic Attack and stroke. Magnetic Resonance Imaging (MRI) of the brain identified areas of ischemia in the left side, and angiography showed occlusion of the left Medial Cerebral Artery (MCA). Cardiac Transthoracic Echocardiogram (TTE) for stroke evaluation incidentally noted a mediastinal abnormality leading to cancer work-up. Computer Tomography (CT) and ¹⁸ F-fluorodeoxyglucose (FDG) PET-CT scan of the chest incidentally revealed an avid 6 cm paraesophagial/subcarinal mass. Further diagnostic work-up with endoscopic and endobronchial ultra sound (EBUS)-guided fine needle aspiration (FNA) of the mass yielded a cytology diagnosis of Germ Cell Tumor (GCT), with choriocarcinoma component. Additionally, high plasma levels of β-human chorionic gonadotrophin (β-HCG) were detected with no evidence of testicular tumor. This exceedingly rare presentation for a primary mediastinal choriocarcinoma underscores the importance of complete investigation of young patients presenting with neurological symptoms compatible with ischemic events. Diagn. Cytopathol. 2017;45:738-743. © 2017 Wiley Periodicals, Inc.

Pediatric Basal Ganglia Region Tumors: Clinical and Radiologic Features Correlated with Histopathologic Findings

PURPOSE

To summarize the clinical and radiologic features of pediatric basal ganglia region tumors (PBGRT) in correlation with their histopathologic findings to reduce inappropriate surgery and identify tumors that can benefit from maximal safe resection.

METHODS

The records of 35 children with PBGRT treated in our hospital from December 2011 to December 2015 were analyzed retrospectively. The clinical and radiologic features of these tumors were summarized and correlated with their histopathologic diagnosis.

RESULTS

Our series included 15 astrocytomas and 11 germ cell tumors (GCTs). Basal ganglia astrocytomas were characterized by various clinical presentations and an ill-circumscribed mass with the involvement of surrounding structures on neuroimaging and mostly occurred in the first decade of life (n = 10; 66.7%). Basal ganglia GCT mostly occurred in the second decade of life (n = 8; 72.7%) with hemiparesis as the most common symptom (n = 9; 81.8%). The tumors were located predominantly in the caput of caudate nucleus (n = 8; 72.7%) with hemiatrophy as the typical sign (n = 8; 72.7%). Occasionally, other tumors also could occur in this region, including primitive neuroectodermal tumor (n = 1), atypical teratoid/rhabdoid tumor (n = 1), anaplastic ependymoma (n = 1), lymphoma (n = 1), extraventricular neurocytoma (n = 1), gangliogliomas (n = 2), oligodendroglioma (n = 1), and dysembryoplastic neuroepithelial tumor (n = 1).

CONCLUSIONS

Astrocytoma and GCT are the most common PBGRTs. Low-grade astrocytomas could benefit from maximal surgical resection, whereas GCTs merit neoadjuvant chemoradiation therapy followed by second-look surgery. We advocate routine testing of tumor markers and analysis of their clinical and radiologic features to optimize the therapeutic strategy.

Pediatric Suprasellar Tumors

The various childhood suprasellar tumors, while pathologically distinct, present similar clinical and surgical challenges as a result of their common anatomic location. These lesions are in close proximity to or may invade the optic nerve and chiasm, pituitary gland and infundibulum, hypothalamus, and third ventricle, leading to presenting features including visual field loss, impairment in visual acuity, endocrine dysfunction, and hydrocephalus. Though many suprasellar lesions are relatively benign in pathology, treatment may be complicated by high surgical morbidity resulting from damage to the hypothalamic-pituitary axis. Here we review the most frequent pediatric lesions occurring in the suprasellar region: craniopharyngioma, chiasmatic glioma, germ cell tumor, Rathke cleft and arachnoid cysts, pituitary adenoma, and histiocytosis. This review outlines both common presenting features and differentiating aspects of these lesions. It also includes classic radiographic presentations and treatment considerations for each lesion.

Intramedullary Spinal Cord Germinoma: A Case Report and Review of Literature

Primary spinal cord germinomas are an extremely rare group of tumors, most commonly reported as single cases in young Japanese adults. They usually present as intramedullary lesions located in the thoracic and thoracolumbar spine. The importance of preoperative diagnosis lies in the fact that by using radiotherapy and chemotherapy, even without surgery, a good cure rate can be achieved in patients with spinal cord germinoma. These tumors, however, demonstrate unspecific imaging characteristics, and only some secrete tumor markers. Therefore, a diagnosis of these lesions before biopsy or resection with pathohistologic examination can be difficult. We present a case of a 28-year-old white man with intramedullary spinal cord germinoma. The tumor was resected completely with electrophysiological monitoring, without a biopsy and frozen section analysis. Postoperative radiotherapy also was part of the treatment. The patient has had no relapse 4.5 years after diagnosis; however, significant neurologic deficits remain. Although not as frequent in white patients, germinoma should be considered as differential diagnosis in cases of young adult patients with intramedullary tumor in the thoracic or thoracolumbar spine. Therefore, spinal mass surgery should commence with a biopsy and intraoperative frozen section analysis. In this way, attempting a gross total resection becomes unnecessary. With an approach of intraoperative biopsy and frozen section analysis, a considerable amount of postoperative neurologic deficits can be reduced.

Nationwide Population-Based Incidence and Survival Rates of Malignant Central Nervous System Germ Cell Tumors in Korea, 2005-2012

Purpose

Malignant central nervous system (CNS) germ cell tumors (GCTs), although rare, are thought to occur more frequently among Asians. However, a recent population-based study revealed no differences in GCT incidence between Asians and Caucasians. Therefore, this study was conducted to determine the incidence and survival rates of CNS GCTs using the national cancer incidence database, and to compare these rates to those in the United States and Japan.

Materials and Methods

We extracted CNS GCT patients diagnosed between 2005 and 2012 from the Korea Central Cancer Registry database. Age-standardized rates (ASRs), annual percentage change, and the male-female incidence rate ratios (IRRs) were calculated. To estimate the survival rate, we used data for patients diagnosed between 2005 and 2010 and followed their cases until December 31, 2013.

Results

The ASR for CNS GCT between 2005 and 2012 was 0.179 per 100,000 (95% confidence interval, 0.166 to 0.193), with an overall male-to-female (M:F) IRR of 2.95:1. However, when stratified by site, the M:F IRR was 13.62:1 for tumors of the pineal region and 1.87:1 for those located in nonpineal regions. The most frequent histologic type was germinoma (76.0%), and the most frequent location was the suprasellar region (48.5%). The 5-year survival rate of germinoma patients was 95.3%.

Conclusion

The incidence rate of CNS GCTs in Korea during 2005-2012 was 0.179 per 100,000, which was similar to that of the Asian/Pacific Islander subpopulation in the United States. Moreover, the CNS GCT survival rate in Korea was similar to rates in Japan and the United States.

Statistical Report of Central Nervous System Tumors Histologically Diagnosed in the Sichuan Province of China from 2008 to 2013: A West China Glioma Center Report

BACKGROUND

Sichuan is a province in the west of China with a population of 81.4 million. This is the first statistical report of central nervous system (CNS) tumors surgically treated and histologically diagnosed in a large Chinese population.

METHODS

All the patient data were obtained from 86 medical facilities, which covered the Sichuan province population. Data from patients who underwent surgery between 2008 and 2013 and corresponding histology samples were re-reviewed in the major pathology centers. All the CNS tumors were categorized according to International Classification of Diseases (ICD)-10 and ICD-O-3 classifications and reviewed manually. The tumor distribution was analyzed and stratified by gender, age, race, and tumor sites. Tumors in some ethnic minorities, such as the Tibetan people, also were analyzed.

RESULTS

The final analytic dataset included 35,496 records. The top four histologic tumors were meningioma (28.51 %), pituitary adenoma (15.00 %), nerve sheath (13.77 %), and glioblastoma (11.82 %). There was a dramatically high incidence of malignant tumor in males. The median age at diagnosis ranged from 13 years (pineal region tumors) to 56 years (metastatic brain tumors). Most of the tumors in the insular lobe or cerebellum were low grade, whereas those in the thalamus or basal ganglia were likely to be high grade. The incidence of malignant tumors or high-grade gliomas in the Tibetans was significantly lower than in the Chinese Han population.

CONCLUSION

This report is a preliminary statistical analysis of brain and spinal tumors in a large Chinese population and may serve as a useful resource for clinicians, researchers, and patients' families.

Expression and mutation of c-Kit in intracranial germ cell tumors: A single-centre retrospective study of 30 cases in China

Although primary central nervous system (CNS) germ cell tumors (GCTs) are one of the most treatable types of malignant brain tumor, a subset of patients remain resistant to standard chemotherapy. Gain-of-function mutations of the c-Kit gene, and KIT protein expression, have been observed in a number of GCTs, including testicular seminoma, ovarian dysgerminoma and mediastinal seminoma in various ethnic groups. Although a small number of studies have reported the role of c-Kit in CNS GCTs, few have focused on Chinese patients exhibiting CNS GCTs. In the present study, the frequency and location of c-Kit mutations and KIT protein expression levels in CNS GCTs were investigated in 30 patients, between January 1994 and October 2014. Immunohistochemical assays suggested that KIT protein expression was present in 59.1% patients (66.7% in males and 42.9% in females); however, no statistically significant correlation was identified between KIT protein expression and patient clinicopathological features. By performing PCR amplification and direct sequencing, 4 mutational hot spots of the c-Kit gene (exons 9, 11, 13 and 17) were examined, and c-Kit gene mutation was identified in 1/17 (5.9%) CNS germinoma cases. This mutation was located in exon 11 at codon 557-558 WK (Tryptophan-Lysine). No c-Kit gene mutations were detected in non-germinomatous GCTs. Imatinib, a tyrosine kinase inhibitor, may be an effective treatment against standard chemotherapy-resistant CNS germinoma patients exhibiting c-Kit mutations.

Atypical pleomorphic neoplasms of the pineal gland: Case report and review of the literature

Background:

Pineal region tumors are rare and diverse. Among them exist reports of pleomorphic xanthroastrocytoma (PXA) and pleomorphic granular cell astrocytoma (PGCA) of the pineal gland. These related tumors are remarkably similar sharing pleomorphic histologic features with only minor immunohistochemical and ultrastructural differences.

Case Description:

We present a case of a 42-year old right-handed woman presented with a longstanding history of migraine headaches which had worsened over the two months leading up to her hospitalization. MRI revealed a 1.7 × 1.3 × 1.6 cm intensely enhancing lesion originating in the pineal gland. The tumor closely resembled PGCA but did not strictly fit the diagnostic requirements of either PGCA or PXA.

Conclusion:

The present case highlights the exotic nature of pineal region tumors with pleomorphic cell histology. Given the diverse range of tumors encountered in the pineal region, pathological confirmation is mandatory. Favorable clinical outcomes demonstrate that surgical resection alone can yield excellent long-term results for tumors falling within the spectrum of pleomorphic lesions of the pineal gland.

Prediction of radiosensitivity in primary central nervous system germ cell tumors using dynamic contrast-enhanced magnetic resonance imaging

OBJECTIVE

To evaluate the feasibility of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for predicting tumor response to radiotherapy in patients with suspected primary central nervous system (CNS) germ cell tumors (GCTs).

METHODS

DCE-MRI parameters of 35 patients with suspected primary CNS GCTs were obtained prior to diagnostic radiation, using the Tofts and Kermode model. Radiosensitivity was determined in tumors diagnosed 2 weeks after radiation by observing changes in tumor size and markers as a response to MRI. Taking radiosensitivity as the gold standard, the cut-off value of DCE-MRI parameters was measured by receiver operating characteristic (ROC) curve. Diagnostic accuracy of DCE-MRI parameters for predicting radiosensitivity was evaluated by ROC curve.

RESULTS

A significant elevation in transfer constant (K(trans)) and extravascular extracellular space (Ve) (P=0.000), as well as a significant reduction in rate constant (Kep) (P=0.000) was observed in tumors. K(trans), relative K(trans), and relative Kep of the responsive group were significantly higher than non-responsive groups. No significant difference was found in Kep, Ve, and relative Ve between the two groups. Relative K(trans) showed the best diagnostic value in predicting radiosensitivity with a sensitivity of 100%, specificity of 91.7%, positive predictive value (PPV) of 95.8%, and negative predictive value (NPV) of 100%.

CONCLUSIONS

Relative K(trans) appeared promising in predicting tumor response to radiation therapy (RT). It is implied that DCE-MRI pre-treatment is a requisite step in diagnostic procedures and a novel and reliable approach to guide clinical choice of RT.

Primary pineal malignant melanoma with B-Raf V600E mutation: a case report and brief review of the literature

Primary pineal melanoma is exceedingly rare, and sufficient treatment options have not been established. Here we describe a 57-year-old male patient who presented with short-term memory disturbance and ataxia. Magnetic resonance imaging of the brain showed a tumor mass in the pineal gland. Biopsy revealed a malignant melanocytic tumor. No primary malignant melanoma was known, and extensive imaging studies including PET-CT excluded other sites affected by a malignant melanoma. The demonstration of the BRAF V600E mutation in the pineal tumor made the patient eligible for intrathecal treatment with vemurafenib. Unfortunately, the patient died 26 days after surgery due to tumor hemorrhage. This is the first report of V600E in primary pineal melanoma, suggesting that a fraction of these rare tumors might additionally benefit from vemurafenib treatment.

Management of CNS germinoma

The following is a general overview of the management of CNS germinomas. Over the last 35 years, CNS germinomas have become one of the pediatric brain tumors with the best outcomes with a greater than 85% overall survival over 5 years. This is in part due to the fact that germinomas are very responsive to chemotherapy and radiation. Some of the major challenges going forward will be to find ways to minimize the adverse effects of our treatments particularly with regard to radiation and to improve the quality of life of patients who develop neurologic, neurocognitive and/or endocrine deficiencies.

Incidence of pineal tumours. A review of the literature

The knowledge of the incidence of pineal tumours is important not only for diagnostic care but also for its therapeutic programme. We reviewed the incidence of pineal tumours reported in literature in an attempt to establish if a difference existed between pineal gland tumours and the pineal region tumours as different authors use both expressions to indicate the same thing. The rate of frequency of these tumours is useful to guide the therapeutic choice for patients as the decisional tree is completely different for either germ cell tumours, pineal gland tumours or pineal gliomas and eventually papillary tumours of the pineal region. According to the French Register of pineal tumours, true pineal tumours represent: 27% pineal parenchymal tumours (PPT), 27% germ cell tumours, 17% gliomas, 8% papillary tumours. True pineal gland tumours are represented by: pineocytomas - (13%), pineal parenchymal tumours with intermediary differentiation PTT-ID - (66%) and pinealoblastomas - (21%). There was no statistical difference found between the French register and the Lyon series concerning histological diagnosis. It seemed to us important to discover its true incidence by comparing the data published in the literature and to stress the utility of the French Register for these uncommon tumours not only for recording new histological cases but also to document clinical symptomatology, therapeutic programmes, length of follow-up and clinical results for each patient treated. A better understanding of their natural history and improved evaluation of different treatments and their complications should contribute to improve clinical results.

Neuroimaging diagnosis of pineal region tumors-quest for pathognomonic finding of germinoma

INTRODUCTION

Our study aimed to elucidate the imaging features for the differentiation of pineal germinoma and other pineal region tumors.

METHODS

Image data sets of computed tomographic (CT) scan and magnetic resonance imaging (MRI) data of 93 pineal region tumors including 33 germinomas, 30 nongerminomatous germ cell tumors (NGGCTs), 20 pineal parenchymal tumors (PPTs), and 10 miscellaneous tumors of pineal region were reviewed. Imaging features on CT and MRI were qualitatively assessed by three readers. To know the reasons for morphological differences between germinomas and NGGCTs, histological investigation was done.

RESULTS

Localized calcification was seen in more than 70 % of germ cells tumors (GCTs: germinomas and NGGCTs) while it was scattered in more than half of PPTs. Cystic components in tumors were most frequent in NGGCTs (62 %). Multiplicity of lesion was restricted to GCTs: 39.4 % in germinoma and 10.0 % in NGGCTs. Thick peritumoral edema was more frequent in germinoma than in NGGCT: 40.6 vs. 14.8 % (p=0.0433, Fisher's test). Bithalamic extension of tumor was seen in 78.8 % of germinomas. It was significantly rare in other groups of tumors (p<0.0001, Fisher's test). The relative collagen amount per unit area was significantly lower in germinoma than in NGGCTs.

CONCLUSION

By paying attention to characteristic features as bithalamic extension, thick peritumoral edema, calcification pattern, multiplicity, and their combination, the preoperative differential diagnosis of pineal germinoma will become more accurate.

Histopathology of pineal germ cell tumors

Germ cell tumors (GCTs) classically occur in gonads. However, they are the most frequent neoplasms in the pineal region. The pineal location of GCTs may be caused by the neoplastic transformation of a primordial germ cell that has mismigrated. The World Health Organization (WHO) recognizes 5 histological types of intracranial GCTs: germinoma and non-germinomatous tumors including embryonal carcinoma, yolk sac tumor, choriocarcinoma and mature or immature teratoma. Germinomas and teratomas are frequently encountered as pure tumors whereas the other types are mostly part of mixed GCTs. In this situation, the neuropathologist has to be able to identify each component of a GCT. When diagnosis is difficult, use of recent immunohistochemical markers such as OCT(octamer-binding transcription factor)3/4, Glypican 3, SALL(sal-like protein)4 may be required. OCT3/4 is helpful in the diagnosis of germinomas, Glypican 3 in the diagnosis of yolk sac tumors and SALL4 in the diagnosis of the germ cell nature of an intracranial tumor. When the germ cell nature of a pineal tumor is doubtful, the finding of an isochromosome 12p suggests the diagnosis of GCT. The final pathological report should always be confronted with the clinical data, especially the serum or cerebrospinal fluid levels of β-human chorionic gonadotropin (HCG) and alpha-fetoprotein.

Incidence of primary central nervous system germ cell tumors in childhood: a regional survey in Kumamoto prefecture in southern Japan

BACKGROUND/AIMS

Central nervous system germ cell tumors (CNS-GCTs) are relatively rare. While their incidence was thought to be higher in East Asia than the USA, recent evidence suggests the difference between Japan and the USA is not statistically significant. The aim of this study was to determine the rate of pediatric primary CNS-GCTs in Kumamoto prefecture, Japan.

METHODS

We surveyed 6,615 new cases of primary intracranial tumors diagnosed in Kumamoto prefecture between 1989 and 2011. Among these, 251 (3.8%) occurred in patients younger than 15 years. The age-adjusted incidence rates were calculated by the direct method using 5-year age groupings; the incidence in the total Japanese population in the year 2000 was the standard.

RESULTS

During the 23-year period, 70 cases of primary GCT were diagnosed. Of these tumors, 31 (44.3%) arose in patients aged between 0 and 14 years (22 boys, 9 girls). Their tumor location was pineal in 45.2%; the other sites were nonpineal. There were more germinomas (64.5%) than nongerminomas (35.5%) in this group. The age-adjusted annual incidence rate was 0.45 cases (boys: 0.64, girls: 0.28) per 10(5) children. At 2.29, the ratio of CNS-GCTs was higher in these boys than girls. Our data showed higher rates than data from CBTRUS 2012 (0.18/10(5)), SEER 2008 (0.15/10(5)) and Germany (0.10/10(5)).

CONCLUSIONS

Our survey showed that the incidence of primary CNS-GCTs in children was higher in Kumamoto prefecture than in the USA and other Western countries, suggesting that racial backgrounds play a role.