Alphafetoprotein and human chorionic gonadotropin determination in cerebrospinal fluid. An aid to the diagnosis and management of intracranial germ-cell tumors

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.

Treatment outcomes and risk factors of patients with intracranial germ cell tumour with choriocarcinoma element or β-HCG level higher than 500 IU/L

BACKGROUND

In previous studies, patients with intracranial germ cell tumour (iGCT) with pure choriocarcinoma or mixed germ cell tumours with choriocarcinoma element showed similar dismal prognoses, with median overall survival (OS) of 22 months and 1-year survival rate of approximately 60%. However, these conclusions need to be updated because radiotherapy, which is the mainstay for this disease, was not applied in a number of patients. Additionally, prognostic factors need to be explored in this population.

METHODS

Clinical data of patients with iGCTs with histologically confirmed choriocarcinoma element or beta-human chorionic gonadotropin (β-HCG) > 500 IU/L were collected from the archives of our institution and retrospectively studied.

RESULTS

A total of 76 patients were eligible for this study. Except for two early deaths, all patients received radiotherapy (craniospinal irradiation [CSI], n = 23; non-CSI, n = 51). The median follow-up duration for the entire series was 63 months (range, 6-188 months). The 5-year event-free survival (EFS) and OS rates were 81.5% and 84.1%, respectively. Among patients who did not have early death or progressive disease after induction chemotherapy, multivariate analysis revealed that chemotherapy cycles (> 4 vs. ≤ 4) (hazard ratio [HR] for EFS 0.144, p = 0.020; HR for OS 0.111, p = 0.028) and β-HCG levels (> 3000 IU/L vs. ≤ 3000 IU/L) (HR for EFS 4.342, p = 0.059; HR for OS 6.614, p = 0.033) were independent factors for survival.

CONCLUSIONS

Patients with iGCTs with choriocarcinoma element or β-HCG > 500 IU/L showed improved survival with radiotherapy-based treatments. Additional chemotherapy cycles could result in additional survival benefits. Patients with β-HCG level > 3000 IU/L had poorer prognosis.

Pineal/germ cell tumors and pineal parenchymal tumors

INTRODUCTION

Pineal region tumors (PRTs) are tumors arising from the pineal gland and the paraspinal structures. These tumors are rare and heterogeneous that account for 2.8-10.1% and 0.6-3.2% of tumors in children and in all ages, respectively. Almost all types and subtypes of CNS tumors may be diagnosed in this region. These tumors come from cells of the pineal gland (pinealocytes and neuroglial cells), ectopic primordial germ cells (PGC), and cells from adjacent structures. Hence, PRTs are consisted of pineal parenchyma tumors (PPTs), germ cell tumors (GCTs), neuroepithelial tumors (NETs), other miscellaneous types of tumors, cystic tumors (epidermoid, dermoid), and pineal cyst in addition. The symptoms of PRTs correlate to the increased intracranial cranial pressure due to obstructive hydrocephalus and dorsal midbrain compression. The diagnostic imaging studies are mainly MRI of brain (with and without gadolinium) along with a sagittal view of whole spine. Serum and/or CSF AFP/β-HCG helps to identify GCTs. The treatment of PRTs is consisted of the selection of surgical biopsy/resection, handling of hydrocephalus, neoadjuvant and/or adjuvant therapy according to age, tumor location, histopathological/molecular classification, grading of tumors, staging, and threshold value of markers (for GCTs) in addition.

METHODS

In this article, we review the following focus points: 1. Background of pineal region tumors. 2. Pineal GCTs and evolution of management. 3. Molecular study for GCTs and pineal parenchymal tumors. 4. Review of surgical approaches to the pineal region. 5. Contribution of endoscopy. 6. Adjuvant therapy (chemotherapy, radiotherapy, and combination). 7.

FUTURE DIRECTION

RESULTS

In all ages, the leading three types of PRTs in western countries were PPTs (22.7-34.8%), GCTs (27.3-34.4%), and NETs (17.2-28%). In children and young adults, the leading PRTs were invariably in the order of GCTs (40-80.5%), PPTs (7.6-21.6%), NETs (2.4-37.5%). Surgical biopsy/resection of PRTs is important for precision diagnosis and therapy. Safe resection with acceptable low mortality and morbidity was achieved after 1970s because of the advancement of surgical approaches, CSF shunt and valve system, microscopic and endoscopic surgery. Following histopathological diagnosis and classification of types and subtypes of PRTs, in PPTs, through molecular profiling, four molecular groups of pineoblastoma (PB) and their oncogenic driver were identified. Hence, molecular stratified precision therapy can be achieved.

CONCLUSION

Modern endoscopic and microsurgical approaches help to achieve precise histopathological diagnosis and molecular classification of different types and subtypes of pineal region tumors for risk-stratified optimal, effective, and protective therapy. In the future, molecular analysis of biospecimen (CSF and blood) along with AI radiomics on tumor imaging integrating clinical and bioinformation may help for personalized and risk-stratified management of patients with pineal region tumors.

Benign and Malignant Tumors of the Pineal Region

Pineal region tumors fall into five broad categories: benign pineal region tumors, glial tumors, papillary tumors, pineal parenchymal tumors, and germ cell tumors. Genetic and transcriptional studies have identified key chromosomal alterations in germinomas (RUNDC3A, ASAH1, LPL) and in pineocytomas/pineoblastomas (DROSHA/DICER1, RB1). Pineal region tumors generally present with symptoms of hydrocephalus including nausea, vomiting, papilledema, and the classical Parinaud's triad of upgaze paralysis, convergence-retraction nystagmus, and light-near pupillary dissociation. Workup requires neuroimaging and tissue diagnosis via biopsy. In germinoma cases, diagnosis may be made based on serum or CSF studies for alpha-fetoprotein or beta-HCG making the preferred treatment radiosurgery, thereby preventing the need for unnecessary surgeries. Treatment generally involves three steps: CSF diversion in cases of hydrocephalus, biopsy through endoscopic or stereotactic methods, and open surgical resection. Multiple surgical approaches are possible for approach to the pineal region. The original approach to the pineal region was the interhemispheric transcallosal first described by Dandy. The most common approach is the supracerebellar infratentorial approach as it utilizes a natural anatomic corridor for access to the pineal region. The paramedian or lateral supracerebellar infratentorial approach is another improvement that uses a similar anatomic corridor but allows for preservation of midline bridging veins; this minimizes the chance for brainstem or cerebellar venous infarction. Determination of the optimal approach relies on tumor characteristics, namely location of deep venous structures to the tumor along with the lateral eccentricity of the tumor. The immediate post-operative period is important as hemorrhage or swelling can cause obstructive hydrocephalus and lead to rapid deterioration. Adjuvant therapy, whether chemotherapy or radiation, is based on tumor pathology. Improvements within pineal surgery will require improved technology for access to the pineal region along with targeted therapies that can effectively treat and prevent recurrence of malignant pineal region tumors.

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.

Diagnosis and Management of Pineal Germinoma: From Eye to Brain

Pineal germinomas can be very complex in terms of presentation, diagnosis, and management. This review attempts to simplify this complexity in an organized manner, addressing the anatomic relationships that provide the basis for the uniqueness of pineal germinoma. Ocular findings and signs and symptoms of elevated intracranial pressure are the keys to suspecting the diagnosis and obtaining the necessary imaging and cerebrospinal fluid studies. Other symptoms can suggest spread beyond the pineal region. Surgery may only be needed to obtain tissue for a definitive diagnosis, as germinoma is highly responsive to chemotherapy and focused radiation therapy. Hydrocephalus, usually related to tumor obstruction of the cerebral aqueduct, may also need to be addressed. Outcome for pineal germinoma is usually excellent, but relapse can occur and may require additional intervention. These issues are detailed in this review.

Pineal region teratoma with metastases in uncommon locations: a case report

Background

We report a rare case in medical literature of a patient with pineal gland teratoma and uncommon metastases. Usually, metastases of this kind of tumor are located in several organs such as lung and breast, but here we found metastases to the spinal cord and vertebrae.

Case presentation

A 35-year-old Asian white man presented with diplopia and acute neural symptoms in the lower limbs such as numbness, tingling, and paralysis. His medical history was notable for pineal teratoma, treated 1 year previously with surgery, radiotherapy, and chemotherapy. Physical examination of the lower limbs showed absent reflexes and sensation with muscle power scale score of 1 in both limbs. Magnetic resonance imaging of brain and spine revealed many lesions in various locations, most compatible with neural, spinal, and vertebral metastases. Unfortunately, the patient died suddenly before any intervention was carried out.

Conclusion

It is extremely rare for pineal region teratoma to metastasize to the spinal cord and vertebrae, thus more vigilant observation and examination should be provided to patients with pineal teratoma to detect any new lesions and prevent them from becoming dangerous.

Differentiation between Germinoma and Craniopharyngioma Using Radiomics-Based Machine Learning

For the tumors located in the anterior skull base, germinoma and craniopharyngioma (CP) are unusual types with similar clinical manifestations and imaging features. The difference in treatment strategies and outcomes of patients highlights the importance of making an accurate preoperative diagnosis. This retrospective study enrolled 107 patients diagnosed with germinoma (n = 44) and CP (n = 63). The region of interest (ROI) was drawn independently by two researchers. Radiomic features were extracted from contrast-enhanced T1WI and T2WI sequences. Here, we established the diagnosis models with a combination of three selection methods, as well as three classifiers. After training the models, their performances were evaluated on the independent validation cohort and compared based on the index of the area under the receiver operating characteristic curve (AUC) in the validation cohort. Nine models were established and compared to find the optimal one defined with the highest AUC in the validation cohort. For the models applied in the contrast-enhanced T1WI images, RF_S + RF_C and LASSO + LDA were observed to be the optimal models with AUCs of 0.91. For the models applied in the T2WI images, DC + LDA and LASSO + LDA were observed to be the optimal models with AUCs of 0.88. The evidence of this study indicated that radiomics-based machine learning could be potentially considered as the radiological method in the presurgical differential diagnosis of germinoma and CP with a reliable diagnostic performance.

[Lesion of optic nerves and chiasm following bifocal germinoma recurrence]

The authors report a patient with recurrent bifocal germinoma of the optical nerves and chiasm after previous combined treatment. The tumor resulted progressive visual acuity loss despite subsequent therapy (glucocorticoid therapy, chemo- and radiotherapy). Differential diagnosis between tumor progression and consequences of radiotherapy was complicated by MRI negative pattern. Subsequent development of the process, signs of anterior visual pathway damage and tumor spread throughout the ventricular system and subarachnoid spaces according to neuroimaging data indicated recurrence of disease.

Pituitary Stalk Enlargement in Adults

Pathologies involving the pituitary stalk (PS) are generally revealed by the presence of diabetes insipidus. The availability of MRI provides a major diagnostic contribution by enabling the visualization of the site of the culprit lesion, especially when it is small. However, when only an enlarged PS is found, the etiological workup may be difficult, particularly because the biopsy of the stalk is difficult, harmful and often not contributive. The pathological proof of the etiology thus needs to be obtained indirectly. The aim of this article was to provide an accurate review of the literature about PS enlargement in adults describing the differences between the numerous etiologies involved and consequent different diagnostic approaches. The etiological diagnostic procedure begins with the search for possible other lesions suggestive of histiocytosis, sarcoidosis, tuberculosis or other etiologies elsewhere in the body that could be more easily biopsied. We usually perform neck, thorax, abdomen, and pelvis CT scan; positron emission tomography scan; bone scan; or other imaging methods when we suspect generalized lesions. Measurement of serum markers such as human chorionic gonadotropin, alpha-fetoprotein, angiotensin converting enzyme, and IgG4 may also be helpful. Obviously, in the presence of an underlying carcinoma (particularly breast or bronchopulmonary), one must first consider a metastasis located in the PS. In the case of an isolated PS enlargement, simple monitoring, without histological proof, can be proposed (by repeating MRI at 3-6 months) with the hypothesis of a germinoma (particularly in a teenager or a young adult) that, by increasing in size, necessitates a biopsy. In contrast, a spontaneous diminution of the lesion is suggestive of infundibulo-neurohypophysitis. We prefer not to initiate steroid therapy to monitor the spontaneous course when a watch-and-see attitude is preferred. However, in many cases, the etiological diagnosis remains uncertain, requiring either close monitoring of the lesion or, in exceptional situations, trying to obtain definitive pathological evidence by a biopsy, which, unfortunately, is in most cases performed by the transcranial route. If a simple surveillance is chosen, it has to be very prolonged (annual surveillance). Indeed, progression of histiocytosis or germinoma may be delayed.

Placental alkaline phosphatase levels in cerebrospinal fluid can have a decisive role in the differential diagnosis of intracranial germ cell tumors

OBJECTIVE

Placental alkaline phosphatase (PLAP) in CSF can provide a very high diagnostic value in cases of intracranial germ cell tumors (GCTs), especially in pure germinomas, to the level of not requiring histological confirmation. Unlike other tumor markers, reliable data analysis with respect to the diagnostic value of PLAP serum or CSF levels has not been available until now. This is the first systematic and comprehensive study examining the diagnostic value of CSF PLAP in patients with intracranial GCTs.

METHODS

From 2004 to 2014, 74 patients (average age 19.6 ± 10.6 years) with intracranial GCTs were evaluated using PLAP from their CSF and histological samples. Chemiluminescent enzyme immunoassay was utilized to measure CSF PLAP in the following tumor sites: pineal (n = 32), pituitary stalk, suprasellar (n = 16), basal ganglia (n = 15), intraventricular (n = 9), and cerebellar (n = 5) regions. In addition to classifying GCT cases, all patients underwent tumor biopsy for correlation with tumor marker data.

RESULTS

PLAP in combination with other tumor markers resulted in extremely high sensitivity and specificity of the diagnostic value of intracranial GCTs. Intracranial GCT cases were classified into 1) germinomas, both "pure" and syncytiotrophoblastic giant cell types (n = 38); 2) nongerminomatous GCTs, choriocarcinomas (n = 9) and teratomas (n = 4); and 3) nongerminomas, other kinds of tumors (n = 23). Consequently, all patients received chemoradiation therapy based on elevation of PLAP and the histopathological results. It was also speculated that the level of PLAP could show the amount of intracranial germ cell components of a GCT. PLAP was 100% upregulated in all intracranial germinoma cases. The absence of CSF PLAP proved that the tumor was not a germinoma.

CONCLUSIONS

The current study is the first systematic and comprehensive examination of the diagnostic value of the tumor marker PLAP in pediatric patients with intracranial GCT. Using the level of PLAP in CSF, we were able to detect the instances of intracranial germinoma with very high reliability, equivalent to a pathological diagnosis.

Biomarkers of Pineal Region Tumors: A Review

Background: The pineal gland, a small, pinecone-shaped organ deep within the brain, is responsible for producing melatonin. The gland consists of pineal parenchymal cells and glial cells that can form neoplasms. Pineal region neoplasms can also arise from germ cells and adjacent structures. This review focuses on detection of serum and cerebrospinal fluid (CSF) biomarkers of germ cell tumors and pineal parenchymal cell tumors, as these types comprise most neoplasms specific to the pineal region. Methods: For this review, we searched PubMed using the following keywords: biomarkers, germ cell tumor, germinoma, melatonin, pineal, pineal gland, pineal neoplasm, pinealoma, pineal parenchymal cell tumor, pineal region, and pineal tumor. We limited our search to full-text English articles and identified other relevant sources from the reference lists of identified articles. Results: Serum and CSF biomarker assays have a role in cases of suspected pineal germ cell or parenchymal neoplasms. Biomarkers including alpha-fetoprotein, beta-human chorionic gonadotropin, and placental alkaline phosphatase inform diagnosis and treatment and are important for monitoring germ cell tumor response to treatment. No biomarkers are currently available that inform diagnosis or treatment of pineal parenchymal tumors, although melatonin assays may have a role in monitoring response to treatment. Conclusion: Serum and CSF biomarkers in conjunction with clinical and radiographic evidence of a pineal region mass can inform the decision whether to undertake stereotactic biopsy or surgical excision or whether to proceed straight to medical treatment.

Predictive factors of overall survival in primary intracranial pure choriocarcinoma

The incidence of primary intracranial pure choriocarcinoma (PIPC) is extremely rare. Only several case and case series have been previously reported; therefore, there is still lack of knowledge about the prognosis and its standard treatment. We performed a collective study of all reported cases of PIPC to identify the predictive factors related with OS. A comprehensive search was performed on Pubmed's electronic database using the terms "primary intracranial choriocarcinoma" and "malignant germ cell tumor". Data about gender, various location, the presence of intratumoral hemorrhage, metastasis and treatment modalities were extracted from the published articles and we analyzed the overall survival based on this predictive factors. 51 cases were eligible and met the inclusion criteria. The majority of the patients were in the child population (44.7%) age between 6 and 12 years old. 77.1% of the patient were male and 22.9% were female. Tumor located other than suprasellar and pineal area showed better prognosis. Median OS of PIPC was 22 months. Patient underwent gross total resection had better outcomes compared with those who only had partial or subtotal resection. Adjuvant therapy (especially chemotherapy) significantly improved OS (p = 0.000, log-rank test). PIPC is chemosensitive and metastasis is the predictive factor for poor prognosis.

A Craniopharyngioma Associated With Elevated Cerebrospinal Fluid HCG Concentrations Misdiagnosed as a Germinoma

Craniopharyngiomas and germinomas are both rare cranial tumors that most commonly present during childhood or adolescence. Although these tumors have different origins, their clinical and radiological features may be similar. In this article, we report the case of a 35-year female patient with clinical and radiological findings and increased human chorionic gonadotrophin (HCG) levels in the cerebrospinal fluid (CSF) that were consistent with a germinoma. However, pathological analysis revealed a craniopharyngioma. This case report indicates that HCG, which is regarded as a specific tumor marker for germinomas in the differential diagnosis of intracranial lesions, is also detectable in other kinds of suprasellar tumors, such as craniopharyngiomas.

A Case of Nongerminomatous Germ Cell Tumor of the Pineal Region: Risks and Advantages of Biopsy by Endoscopic Approach

A 21-year-old male was admitted to our department with headache and drowsiness. CT scan and MRI revealed acute obstructive hydrocephalus caused by a pineal region mass. The serum and CSF levels of beta-human chorionic gonadotropin (beta-hCG) were 215 IU/L and 447 IU/L, respectively, while levels of alpha-fetoprotein (AFP) were normal. A germ cell tumor (GCT) was suspected, and the patient underwent endoscopic third ventriculostomy (ETV) with biopsy. After four days from surgery, the tumor bled with mass expansion and ETV stoma occlusion; thus, a ventriculoperitoneal shunt was positioned. After ten months, the tumor metastasized to the thorax and abdomen with progression of intracerebral tumor mass. Despite the aggressive nature of this tumor, ETV remains a valid approach for a pineal region mass, but in case of GCT, the risk of bleeding should be taken into account, during and after the surgical procedure.

Serum and Cerebrospinal Fluid Human Chorionic Gonadotropin (hCG) and alpha-fetoprotein (AFP) in Intracranial Germ Cell Tumors

We report a retrospective study on serum and cerebrospinal fluid (CSF) alpha-fetoprotein (AFP) and β-human chorionic gonadotropin (βhCG) determination in a series of 30 patients bearing intracranial germ cell tumors. At diagnosis five patients had high serum and CSF AFP levels. No patient had positive serum AFP and negative CSF AFP or vice versa. Twelve of 30 patients had serum βhCG levels above 5 mIU/mL, eight had high βhCG only in CSF, and ten were completely negative. During treatment and follow-up both markers were accurate indicators of the response to therapy, decreasing rapidly and often becoming normal already after the first phase of treatment. We conclude that these two markers, and mostly βhCG, may be useful in the diagnosis and monitoring of the response to therapy of patients with intracranial germ cell tumors.

Evaluation and treatment of Langerhans cell histiocytosis patients with central nervous system abnormalities: Current views and new vistas

Central nervous system (CNS) involvement in Langerhans cell histiocytosis (LCH) can include mass lesions of the hypothalamic pituitary axis, choroid plexus, cerebrum, and cerebellum or magnetic resonance imaging (MRI) signal abnormalities of the cerebellum, pons, and basal ganglia. The term neurodegenerative (ND) CNS-LCH has been given to the MRI signal abnormalities and neurologic dysfunction, although initially patients may have no clinical symptoms. Standardized evaluations to better understand the natural history and response to therapy are needed. We propose guidelines for clinical, radiologic, and physiologic tests as a framework for developing the best methods of evaluation, which can then be tested in prospective treatment protocols.

Teratoma of the nervous system: A case series

Teratoma is a common form of germ cell tumors composed of multiple tissues foreign to the site in which arise with a histological representation of all three germ cell layers. Intracranial teratomas are very rare. In this study, we report three cases of intracranial teratomas with an interesting clinical course, neuroradiology, and outcome. In addition, we review the literature and convey important messages to the neuroscience community regarding issues related to the management of these rare tumors. The present cases are interesting examples of intracranial teratoma in terms of location of the tumor and neuroimaging findings. Delay in surgical intervention may complicate the course of the disease with progressive enlargement of tumors and development of complication including hydrocephalus. Using endoscopic surgical techniques may emerge as the preferred intervention option as compared to other traditional methods. We recommend the establishment of a national and international registry for intracranial tumors.

Pineal germ cell tumors: Two cases with review of histopathologies and biomarkers

Pineal germ cell tumors (GCTs) are primarily seen in pediatric and Asian populations. These tumors are divided into germinomatous and non-germinomatous GCTs (NGGCTs). GCTs are thought to arise by misplacement of totipotent stem cells en route to gonads during embryogenesis. Intracranial GCTs display an affinity to develop along the pineal-suprasellar axis and have variable manifestations dependent upon the location of the tumor. Management and outcomes are driven by histopathologies. In this study, we highlight two cases of pineal GCTs and present a review of the literature with an emphasis on histopathologies and biomarkers.

Microsurgical resection of pineal region tumors

The extensive variety of possible histologic subtypes makes it imperative to establish a tissue diagnosis in patients with pineal region tumors. Management decisions regarding adjuvant therapy, prognosis, and follow-up strategies vary with the histologic diagnosis. Specialized surgical and stereotactic techniques have evolved to provide the neurosurgeon with an array of safe and effective options for obtaining a tissue diagnosis. Advanced microsurgical techniques combined with improved preoperative management and postoperative critical care methods have made aggressive surgical resection a mainstay of management. Aggressive surgical resection has resulted in excellent long-term prognoses for nearly all patients with benign tumors and a large percentage of patients with malignant tumors. However, pineal region surgery remains fraught with potential pitfalls, and these favorable results are dependent on an advanced level of surgical expertise.

A Case of Nongerminomatous Germ Cell Tumor with Fulminant Course Concomitant Leptomeningeal Metastasis

We present the case of a 9-year-old boy with a non-germinomatous germ cell tumor (NGGCT) in the pineal gland that exhibited a fulminant course following chemo- and radiotherapy. After the detection of the tiny cerebellar enhancing nodule at the end of chemo- and radiotherapy, tumor seeding progressed rapidly into the entire cisternal space. We herein report a rare case of NGGCT with fulminant clinical course of concomitant cerebellar seeding, with review of literature.

CNS germ cell tumors: a clinical review and future directions

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

Central nervous system germ cell tumors: an update

PURPOSE OF REVIEW

Malignant germ cell tumors in the central nervous system are rare and not well known because they occur mainly in adolescents, an age in which patients are dispersed in adult and pediatric wards. Their biology starts to be unraveled by high-throughput genomics and their treatment is now well defined thanks to international studies, including patients from childhood through adulthood.

RECENT FINDINGS

Chemotherapy gained definitively a role apart from radiotherapy in order to improve tumor control in secreting neoplasms, but also to decrease the volume or dose of radiation therapy in germinomas. Neurocognitive outcome remains good with some disparities because of tumor location, patients with pineal tumors being less impaired than those with supratentorial malignant germ cell tumors. Alterations in the KIT/RAS as well as in the mTOR/AKT pathways have been frequently reported and could represent interesting opportunities to introduce targeted therapies in these neoplasms.

SUMMARY

Diagnosis and treatment of malignant germ cell tumor of the brain are now well established within experienced multidisciplinary teams taking care of adolescents and young adults. The prognosis of secreting tumors has not yet reached the excellent results obtained for germinomas but aggressive chemotherapy including high-dose chemotherapy with stem-cell support may contribute to improve their outcome. The role of targeted therapies has yet to be determined in view of the recently described molecular findings.

Intracranial pure yolk sac tumor in the anterior third ventricle of an adult: A case report

A 45-year-old female patient presented with symptoms of polydipsia and polyuria, menopause, headache, gait disturbance and deteriorated mental state. Brain magnetic resonance imaging (MRI) showed an irregular mass in the anterior third ventricle. The tumor was excised using a transfrontal approach from the anterior section of the third ventricle. The histological diagnosis was of an intracranial pure yolk sac tumor. The patient underwent radiotherapy and suffered no tumor recurrence one year after the surgery. Overall, when heterogeneous enhancement and an irregular mass with surrounding invasion and ventricular dilation are observed in the anterior third ventricle of an adult, a yolk sac tumor should be considered, and MRI may aid the differential diagnosis. A combination of surgical resection and radiotherapy is recommended for the yolk sac tumor.

Clinical analysis of intracranial germinoma's craniospinal irradiation using helical tomotherapy

OBJECTIVE

To evaluate the short-term clinical outcomes of intracranial germinoma patients treated with craniospinal irradiation (CSI) using helical tomotherapy (HT) system in our center.

METHODS

Twenty-three patients who were treated with CSI in our center from January 2008 to July 2012 were collected, with an average age of 20. All of the patients' CSI used the HT system. The total doses were 27-36 Gy/15-20 F (1.5-2 Gy per fraction), and total local doses were 46-60 Gy/30-50 F (5 fractions per week). All female patients for CSI were treated with left-right parallel-opposed field irradiation to protect their ovarian functions. Median follow-up time was 30.9 months (range, 5-67 months). The SPSS19.0 software was used, and the overall survival (OS) was calculated using the Kaplan-Meier method.

RESULTS

Among 17 patients with assessable tumors, 9 cases (52.9%) were CR, 7 cases (41.2%) were PR, and 1 case (5.9%) was SD. Hematological toxicity was the severest side-effect occurred in the procedure of CSI. The level 1-4 acute leukopenia were 8.7%, 30.4%, 34.8% and 21.7% and the level 1-4 acute thrombopenia were 8.7%, 30.4%, 21.7% and 8.7%, respectively.

CONCLUSIONS

For primary intracranial germinomas, HT can be used to implement CSI for simplifying radiotherapy procedures, improving radiotherapy accuracy, enhancing protection of peripheral organs at risk (ORA) and guaranteeing therapeutic effects. With the acceptable acute and long-term toxicity, CSI using HT in intracranial germinoma patients can be a safe and alternative mode.

Tumoral markers in tumors of the pineal region

In cases of pineal tumors, a germ cell tumor should always be suspected. As some of them are secreting tumors, tumoral markers (AFP and/or hGC) are an important part of the diagnostic process. Their positivity either in the serum and/or in the cerebrospinal fluid may lead to an accurate diagnosis, avoiding a potentially dangerous surgical biopsy. Follow-up of tumoral markers is useful during and after treatment in order to monitor response to chemotherapy or a remission status.

Potential role of ventricular tumor markers in CNS germ cell tumors

BACKGROUND

There is increasing reliance on oncoprotein assays such as the β-subunit of human chorionic gonadotropin (β-hCG) and alpha-fetoprotein (AFP) for diagnosis or confirmation of histology of central nervous system (CNS) germ cell tumors (GCT), but the relative diagnostic sensitivity and reliability of assays from serum (S), lumbar (L), and ventricular (V) cerebrospinal fluid (CSF) are uncertain.

PROCEDURE

A total of 86 patients with CNS GCT were identified from our database. Fourteen patients had contemporaneous β-hCG and/or AFP measurements from serum, ventricular, and lumbar CSF at diagnosis (n = 13) or relapse (n = 1), constituting the subjects for this report. Their primary tumor sites were: pineal (n = 8), suprasellar (n = 1), or both (n = 5). Their mean age at diagnosis was 16.0 years (range 9.1-25.9). The male:female sex ratio was 13:1.

RESULTS

For the germinoma-treated patients (n = 8), the median (range) β-hCG values (S, V, L) were 0 (0-6.9), 7.0 (0-57.4), 8.3 (0-34.0) mIU/ml. For patients managed as mixed malignant GCT (MMGCT) (n = 6), the median (range) β-hCG values (S, V, L) were 3.9 (0-58.0), 3.6 (0-147.0), 61.8 (0-358.0) mIU/ml. The median (range) AFP values were 7.5 (0-27,400.0), 2.0 (0-2,981.0), 3.0 (0-14,015.0) ng/ml. Lumbar CSF β-hCG values were equal or greater than those in ventricular CSF or serum in 12 of 13 cases (92.3%). All patients with MMGCT had lumbar AFP equal or greater than the ventricular CSF values, while serum AFP values remained highest.

CONCLUSIONS

Ventricular CSF values cannot be considered a replacement for lumbar CSF. Lumbar CSF is the most reliable source of tumor markers to establish baseline and follow-up diagnostic endpoints.

Diagnostic sensitivity of serum and lumbar CSF bHCG in newly diagnosed CNS germinoma

BACKGROUND

Marked elevations of AFP and bHCG in serum or CSF may serve as surrogate diagnostic markers in lieu of histology for primary CNS mixed, malignant germ cell tumors. There is less information on the diagnostic sensitivity of bHCG assays in germinoma.

PROCEDURE

We report baseline serum and lumbar CSF bHCG values in 58 newly diagnosed, histologically confirmed germinoma patients gathered from two prospective clinical trials which required that patients have a normal AFP and bHCG ≤50 mIU/ml in serum and lumbar CSF.

RESULTS

The location of the primary tumors was: suprasellar(23); pineal(20); suprasellar/pineal(9); and other sites(6). The mean age of the study population was 13.5 (4.3-25.9) years. A total of 23(40%) patients had elevations of bHCG in either serum or CSF, 20(34.5%) of whom had only bHCG elevations in CSF. The patients' bHCG profiles were divided into four categories: I (normal serum and lumbar CSF bHCG), 35(60%); II (normal serum and elevated CSF bHCG), 20(34.5%); III (elevated serum and CSF bHCG), 2(3.5%); and IV (elevated serum and normal CSF bHCG), 1(2%). The median CSF bHCG level was 7.7(2.5-16) in the 22 patients with abnormal CSF values and the lumbar value was higher than the serum value in 20 of 23(87%) patients with bHCG elevations.

CONCLUSIONS

Lumbar CSF was a more informative screen for bHCG than serum but the majority of patients (60%) had normal bHCG values at diagnosis. Until a more sensitive tumor marker for germinoma is devised, histologic confirmation remains the standard of care. Pediatr Blood Cancer 2012; 59: 1180-1182. © 2012 Wiley Periodicals, Inc.

Recurrent pure CNS germinoma with markedly elevated serum and cerebrospinal fluid human chorionic gonadotropin-beta (HCGβ)

Controversy continues regarding what level of serum and/or cerebrospinal fluid (CSF) human chorionic gonadotrophin-beta (HCGβ) is consistent with pure germinoma of the central nervous system (CNS). We report a 10-year female with biopsy-proven pure germinoma and normal serum and CSF HCGβ who experienced subsequent biopsy-proven recurrences of germinoma. At recurrence, serum and CSF HCGβ levels were 560 and 3,202 mIU/ml, respectively, although final autopsy demonstrated pure germinoma. This case illustrates the need to re-evaluate the assumption that pathologically pure germinomas may be associated with high levels of HCGβ which are unrelated to nongerminomatous germ cell tumor (NGGCT)/choriocarcinomatous elements.

Neonatal brain tumours - a review

Brain tumors in infants (under the age of 1 yr) are mercifully rare. Nonetheless, neonatal tumours present a treatment challenge to those involved. Surgery can be technically challenging, if possible at all, and the sensitivity of the developing nervous system to the side-effects of radio- and chemotherapy has limited their utility as adjunctive treatments. The risk/benefit equation in the planning of treatment of neonatal tumours using these modalities is further complicated by the fact that these tumours are often histologically benign, of large dimensions, but are often situated in locations that lead to a fatal outcome. This review article seeks to provide guidance on the management of neonatal patients and infants up to 1 year of age with brain tumours based on evidence from the literature.

Germinoma with malignant transformation to nongerminomatous germ cell tumor

The authors describe the case of a young girl with suprasellar germinoma. Six weeks after this diagnosis, just prior to initiation of therapy, serum and CSF marker analysis revealed sudden and marked elevation of alpha-fetoprotein, indicating transformation of her germinoma to a nongerminomatous germ cell tumor. She underwent chemotherapy and radiation therapy per the national treatment approach for the new diagnosis, with subsequent return of her serum and CSF tumor markers to normal levels. To the authors' knowledge, this is the first case in the English-language literature of a nongerminomatous germ cell tumor resulting from conversion of germinoma at the original site of presentation.

Gonadotrophin-independent precocious puberty in an eight-year-old boy due to ectopic human chorionic gonadotrophin from the central nervous system

We present the case of an eight-year-old boy with advanced isosexual precocity associated with an elevated serum total-beta human chorionic gonadotrophin (HCG) and markedly elevated serum total testosterone. Radiological investigation discovered a lesion in the left thalamus and no peripheral tumour. Serum:cerebrospinal fluid (CSF) HCG ratio was approximately 1:1, consistent with a central nervous system source of HCG, with thalamic germinoma strongly suspected. Consent was not obtained for biopsy of the lesion. The patient underwent multiagent chemotherapy with return of serum HCG to normal. We discuss mechanisms of HCG-mediated sexual precocity in both boys and girls and the importance of CSF HCG.

Successful neoadjuvant synchronous chemo- and radiotherapy for disseminated primary intracranial choriocarcinoma: case report

We report a 17-year-old male with disseminated intracranial choriocarcinoma at the basal ganglia whose consciousness level was very low at diagnosis. He received neoadjuvant therapy (NAT) consisting of combined chemo- and radiotherapy prior to radical excision of the tumor. Postoperatively he was treated with three courses of high-dose chemotherapy (carboplatin (CBDCA), methotrexate (MTX), and etoposide (VP-16)) and peripheral blood stem-cell transplantation. This combination of therapies resulted in tumor regression on MRI and remarkable improvement in his neurological condition. Ours is the first report of the effectiveness of NAT followed by radical surgery in a patient with disseminated primary intracranial choriocarcinoma.

Epidemiological survey of central nervous system germ cell tumors in Canadian children

OBJECTIVES

To determine the incidence and characteristics of pediatric patients with central nervous system (CNS) germ cell tumors (GCT) in Canada.

METHOD

A national retrospective review of hospital charts was done on all patients with CNS GCT diagnosed between 1990 and 2004. Patients had to be under age 18 years at the time of diagnosis of a CNS germ cell tumor and be a resident of Canada. Information extracted included age and year of diagnosis, pathological diagnosis, location of tumor, evidence of disseminated disease at time of diagnosis and biological markers.

RESULTS

One hundred and twenty-one cases were identified (83 germinoma; 38 non-germinoma germ cell tumor). The mean annual incidence of CNS GCT was 1.06 per million children (0.7 per million for germinoma; 0.3 per million for NGGCT). Though yearly incidences varied, there was no clear trend to increased incidence. Male predominance was noted (2.4:1 for germinoma; 11:1 for NGGCT). The primary locations were the pineal and suprasellar regions. At the time of diagnosis, disseminated disease was not uncommon (22% germinoma; 32% NGGCT). Beta human gonadotrophin was elevated in the serum, cerebrospinal fluid (CSF) or both in 7% of patients with germinoma and 36% of patients with NGGCT. Elevation of alpha-fetoprotein in serum, CSF or both was seen in 34% of patients with NGGCT.

CONCLUSION

The incidence of CNS germ cell tumors in Canadian children is similar to that observed in other Western countries.

Pineal region teratoma with high serum and CSF alpha-fetoprotein levels

We report a patient with an immature teratoma of the pineal region with high levels of alpha-fetoprotein (AFP) in serum and cerebrospinal fluid. This is very rare and to the best our knowledge, the second case reported in the literature.

Intracranial optic nerve germinoma

A 11-year-old boy presented with complaints of diminution of vision in the left eye for three months. On examination, the vision in this eye was reduced to only perception of light. Magnetic resonance imaging revealed a thickened left intracranial optic nerve. The lesion was explored by a pterional craniotomy. At surgery, the left optic nerve was diffusely thickened. The biopsy of a fleshy mass along the optic nerve showed that it was a germinoma on histopathology. Isolated optic nerve germinomas are extremely rare. Exclusive primary involvement of the intracranial portion of the optic nerve by a germinoma has not been reported in the literature. This rare case is discussed and the relevant literature has been reviewed.

Principles of treatment of the pineal region tumors

BACKGROUND

A pineal region tumor is an uncommon deep-seated, heterogeneous group of mass lesions of the brain, and the management strategy of any types of these tumors remains controversial. It is the purpose of this communication to present results of our experience in treating patients with these neoplasms.

METHODS

From 1976 to 1999 about 700 patients with tumors of the pineal region and posterior third ventricle were managed at the Burdenko Neurosurgery Institute. In more than 330 cases the tumor was removed. In this paper we present results of 287 patients with histologically verified pineal region tumors for the period from 1976 to 1999. All of them had verified tumor histology, excluding only five cases in which stereotactic biopsy procedures were uninformative. There are four main groups of tumors: the germ cell tumors-87 (31%); the pineal parenchymal tumors-75 (27%); the glial tumors-77 (27%); and miscellaneous-43 (15%). There were 255 surgical procedures for tumor removal performed in 244 and stereotactically guided biopsies in 61 patients, 168 (58%) with obstructive hydrocephalus who underwent cerebrospinal fluid shunting. Radiation therapy was administered in 145 (51%) and chemotherapy in 16 patients. Follow-up data were collected in 209 cases (80%). Survival was calculated with the Kaplan-Meier product limit method.

RESULTS

The occipital transtentorial and infratentorial supracerebellar approaches were the most commonly used on our series-138 (54%) and 87 (34%), respectively. In the remaining cases, subchoroidal approach, approach through the fourth ventricle, and the combined approaches were used. A total tumor removal was achieved in 148 operations (58%), subtotal in 74 (29%) and partial in 33 (13%). The projected 5-year and 10-year survival rates for patients with malignant pineal tumors, who received irradiation after tumor resection or underwent radiation therapy alone, were: 95% and 88% for pure germinomas, 80% and 50% for high grade gliomas, 44% and 0% for malignant pineal parenchymal tumors, and 20% and 0% for malignant germ cell tumors, respectively.

CONCLUSIONS

Benign pineal tumors should be cured with surgery alone. Malignant tumors should be treated with aggressive resection followed with irradiation and chemotherapy. Pure germinomas, which are exquisitely radiosensitive, can be cured by conventional radiation therapy alone.

Intracranial germ cell tumors: a retrospective study of 44 children

This 16-year retrospective study review sought to determine the factors influencing prognosis and treatment results of all patients with primary intracranial germ cell tumors treated at our hospital who were younger than 17 years of age at the time of diagnosis. A total of 44 patients were treated during the study period, including 32 males and 12 females with a male:female ratio of 2.67:1. The median age at diagnosis was 12 years and 5 months of age (range = 2-16 years). The 44 intracranial germ cell tumors consisted of 27 pure germinomas (61.4%) and 17 nongerminomatous germ cell tumors, including 10 mixed germ cell tumors (22.7%), three yolk sac tumors (7.8%), two immature teratomas (4.5%), and two choriocarcinomas (4.5%). Univariate analysis of prognostic factors using Kaplan-Meier survival estimates revealed that only histologic tumor type was correlated with outcome (P < 0.005). The projected 5-year overall survival and event-free survival rate of patients with germinomas vs those with intracranial germ cell tumors were 92.6%, 92.6% vs 47.3%, and 42.1%, respectively. Our analysis suggests that radiation involving the spinal axis has limited usefulness in patients with intracranial germ cell tumor, although better results have been obtained for germinomas using radiotherapy in this study.

Neuroendoscopic anatomy and surgery in pineal region tumors: role of neuroendoscopic procedure in the 'minimally-invasive preferential' management

The therapeutic modalities for pineal region tumors in Western countries differ from those in far-eastern countries, that is, Japan and Korea, mainly because of the different patient populations. The majority of pineal region tumors in Japan and Korea are radio sensitive and/or chemosensitive, and adjuvant therapy rather than extensive surgery plays the main part in the treatment of these tumors. The authors have applied minimally-invasive preferential management in pineal region tumors in last 8 years. For the therapeutic regimen, if the tumor markers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were not detected in serum and there was significant ventricular dilation visualized on neuroimages, neuroendoscopic surgery was first applied for tumor debulking with tissue diagnosis and gross morphological analysis of the tumor and the intraventricular structures, followed by third-ventriculostomy. In the results, our minimally-invasive preferential regimen clarified the precise indication for neuroendoscopic procedures, and the majority of our patients with dilated ventricles and no evidence of tumor markers were treated satisfactorily with effective neuroendoscopic procedures as the initial procedure. Then avoided unnecessary craniotomy and radiotherapy and promised excellent therapeutic outcomes. Neuroendoscopic procedures have a great advantage in the management of chemo- or radiosensitive tumors, such as germinoma, pineoblastoma, or primitive neuroectodermal tumor. The neuroendoscopic anatomy including the lateral and third ventricles with a pineal region tumor with or without tumor dissemination was described in detail, together with the neuroendoscopic surgical technique.

Efficacy of neuroendoscopic procedures in minimally invasive preferential management of pineal region tumors: a prospective study

OBJECT

This prospective study is based on a consecutive series of 20 patients with pineal region tumors who underwent minimally invasive preferential management. The purpose of this report is to discuss the role of neuroendoscopic procedures in the management of pineal region tumors.

METHODS

If the tumor markers alpha-fetoprotein and human chorionic gonadotropin were not detected in serum and there was significant ventricular dilation visualized on neuroimages, neuroendoscopic surgery was first applied for tumor debulking with tissue diagnosis and gross morphological analysis of the tumor and the intraventricular structures, followed by third ventriculostomy. Subsequent procedures were determined on the basis of verified individual tumors. For treatment of germinomas and pineoblastomas, if no tumor dissemination was confirmed by pre-, intra-, or postoperative findings, stereotactic radiotherapy or radiosurgery was performed after one course of chemotherapy with the ICE regimen (isofomid, cisplatin, and etoposide) and followed by two additional courses of chemotherapy. For treatment of malignant germ cell tumors, after extensive surgery, adjuvant chemotherapy with the ICE regimen was performed in three courses in all cases. Then radiotherapy was started using various methods, depending on the evidence of tumor dissemination. For treatment of teratomatous and neuroectodermal tumors other than pineoblastomas, extensive surgical removal was performed. As for adjuvant therapy, if the tumor was a low-grade glioma or if the patient was younger than 5 years of age, postoperative treatment did not include radiotherapy. If the tumor was a malignant teratoma or high-grade glioma, conventional focal radiotherapy was performed, followed by chemotherapy with ICE for 1 year. All but two treated patients had ventriculomegaly. Neuroendoscopic procedures were performed in six of 15 treated patients. Neuroendoscopic biopsy with tumor debulking offered enough material for tissue diagnosis, including immunohistochemical analysis and, in one case, revealed evidence of tumor dissemination undetectable on neuroimaging. With one exception, no shunt was required in any patient undergoing endoscopic third ventriculostomy. Stereotactic radiotherapy was performed in indicated cases. Favorable therapeutic outcomes were obtained in all cases of germinoma and pineoblastoma, with follow-up periods ranging from 24 months to 6.5 years.

CONCLUSIONS

Our minimally invasive preferential regimen clarified the precise indication for neuroendoscopic procedures, and the majority of our patients with dilated ventricles and no evidence of tumor markers were treated satisfactorily with effective neuroendoscopic procedures as the initial procedure, avoiding unnecessary craniotomy and radiotherapy and promising excellent therapeutic outcomes. The treatment for malignant pineal region tumors remains a subject for further study.

Primary meningeal melanocytoma of the pineal region. Case report

A unique case of a meningeal melanocytoma located in the pineal region is presented. This 48-year-old man presented with a round pineal region tumor that caused triventricular hydrocephalus and exhibited slow clinical progression. During surgery a black encapsulated tumor was found and totally removed. On histopathological examination, the tumor proved to be a meningeal melanocytoma. In this report cell culture data are presented and the relevant literature is reviewed. The problems of histopathological diagnosis and management of patients with melanocytomas are also discussed.

Blood to cerebrospinal fluid human chorionic gonadotropin-beta ratios in intracranial germ cell tumors

Levels of human chorionic gonadotropin-beta (HCG-beta) are elevated in up to 43% of patients with intracranial germ cell tumors (GCTs) and are useful in the diagnosis of these tumors and the follow up of such patients. The ratio of blood HCG-beta to lumbar cerebrospinal fluid (CSF) HCG-beta in these patients at presentation has not been defined. Twenty-two patients with intracranial GCTs have been treated at St. Bartholomew's Hospital over the past 15 years. Two (17%) of 12 germinomas and seven (70%) of 10 nongerminomatous GCTs had elevated blood HCG-beta at presentation. Four cases of pineal region GCTs (one of 12 germinomas and three of 10 nongerminomatous GCTs) had paired, elevated, blood and lumbar CSF HCG-beta levels. The mean blood to CSF ratio was 1:10 (range 1.7-18.4), which is substantially lower than the ratio of 286:1 reported in systemic GCTs. The authors confirm the finding of a previous single report showing that ventricular CSF HCG-beta sampling via an accessible ventriculoperitoneal shunt reservoir may give a spuriously negative result, and they discuss the pathophysiology of the blood-brain barrier in the pineal region and the implications of the intrathecal administration of chemotherapy.