Congenital brain tumors: diagnostic pitfalls and therapeutic interventions

Congenital Brain Tumors: Surgical Outcomes and Long-Term Prognostic Factors

OBJECTIVE

To evaluate long-term outcomes of surgical resection for congenital brain tumors (CBTs) in infants under one year of age and to identify factors related to survival.

METHODS

Our retrospective study analyzed infants who underwent gross total or subtotal resection (STR) for CBTs between 2001 and 2019. Data were obtained from medical records, including demographics, clinical presentation, diagnosis, tumor characteristics, and presence of hydrocephalus. Additional factors such as preoperative and/or postoperative ventriculoperitoneal shunt placement and adjuvant chemotherapy or radiotherapy were also reviewed. Cox regression analysis was used to identify factors associated with survival.

RESULTS

The study included 70 patients, with median age at surgery of 198.5 days, and 28 (40%) were girls. Seizures (31.4%) and vomiting (24.3%) were the most common presenting symptoms. High-grade tumors were present in 29 (41.4%) patients. Gross total resection was achieved in 64.3% of cases, with surgical mortality rate of 7.1%. Overall survival rates at 5 and 10 years were 78% and 63%, respectively. Long-term follow-up data were available for 61 patients (87%), with median follow-up of 74.2 months. Among 45 long-term survivors, 55.5% had neurological sequelae. Factors associated with reduced survival included high-grade, preoperative hydrocephalus, larger tumor size, and ventriculoperitoneal shunt placement. The extent of resection improved survival only in low-grade tumor cases. Multivariable Cox regression analysis identified tumor grade and size as independent predictors of poor prognosis.

CONCLUSIONS

Surgical resection remains crucial for treating CBTs in infants under one year, yet the aggressive nature of malignant tumors results in suboptimal outcomes regarding prognosis.

The Role of Early and Delayed Surgery for Infants with Congenital Brain Tumors

PURPOSE

The present study aimed to evaluate the role of early and delayed surgery in congenital brain tumors and analyze the clinical outcomes of infantile brain tumors.

MATERIALS AND METHODS

We performed a retrospective cohort study on 69 infantile brain tumors at a single institution from January 2008 to June 2023. Outcomes were assessed as early mortality (within 30 days following surgery) to evaluate the risk of early surgery in congenital brain tumors. Outcomes of recurrence and overall survival were analyzed in infantile brain tumors.

RESULTS

Surgery-related early mortality appeared to occur in young and low-body-weight patients. Cut-off values of age and body weight were found to be 1.3 months and 5.2 kg to avoid early mortality. Three patients (3/10, 30%) showed early mortality in the early surgery group, and early mortality occurred in one patient (1/14, 7.14%) in the delayed surgery group, whose tumor was excessively enlarged. Younger age at diagnosis (< 3 months of age; hazard ratios [HR], 7.1; 95% confidence intervals [CI], 1.4 to 35.6; p=0.018) and leptomeningeal seeding (LMS; HR, 30.6; 95% CI, 3.7 to 253.1; p=0.002) were significant independent risk factors for high mortality in infantile brain tumors.

CONCLUSION

We suggest delaying surgery until the patient reaches 1.3 months of age and weighs over 5.2 kg with short-term imaging follow-up unless tumors grow rapidly in congenital brain tumors. Younger ages and the presence of LMS are independent risk factors for high mortality in infantile brain tumors.

Intracranial Tumors in the First Year of Life

Intracranial tumors in the first year of life are rare and, in this age group, are the second most common type of pediatric cancer after leukemias. As the more common solid tumor in neonates and infants, they present some peculiarities such as the high incidence of malignancies. Routine ultrasonography made easier to detect intrauterine tumors, but diagnosis can be delayed due to the lack or scarcity of recognizable symptoms. These neoplasms are often very large and highly vascular. Their removal is challenging, and there is a higher rate of morbidity and mortality than seen in older children, adolescents, and adults. They also differ from older children with respect to location, histological features, clinical behavior, and management. Pediatric low-grade gliomas represent 30% of the tumors in this age group and comprise circumscribed and diffuse tumors. They are followed by medulloblastoma and ependymoma. Other non-medulloblastoma embryonal neoplasms, former known as PNETS, are also commonly diagnosed in neonates and infants. Teratomas have an expressive incidence in newborns but decline gradually until the end of the first year of life. Immunohistochemical, molecular, and genomic advances are impacting the understanding and targeting of the treatment of some tumors, but, despite all these advances, the extent of resection remains the most important factor in the prognosis and survival of almost all types of tumors. The outcome is difficult to estimate, and 5-year survival ranges from one-quarter to three-quarters of the patients.

Congenital tumors of the central nervous system: an institutional review of 64 cases with emphasis on tumors with unique histologic and molecular characteristics

Congenital brain tumors are rare accounting for 0.5%-1.9% of all pediatric brain tumors. While different criteria have been used to classify a tumor as congenital, those diagnosed prior to 6 months of age are considered to be "probably" congenital in origin. We performed an institutional review of all central nervous system (CNS) tumors (surgical and autopsy specimens from 1990 to 2019) in patients less than 6 months old. Sixty-four unique cases were identified, and these accounted for 2.0% of all CNS tumor specimens at our institution. The most common tumor types were high-grade gliomas, low-grade gliomas and medulloblastomas. Atypical teratoid rhabdoid tumors, choroid plexus tumors and germ cell tumors also accounted for a significant portion of the cohort. Seven tumors were diagnosed prenatally. The most common clinical presentation at diagnosis was increased head circumference. At the conclusion of the study, over half of the patients were alive including all patients with WHO grade I and II tumors. Ninety-two percent of cases were classifiable using the 2016 WHO system, and when available, molecular findings supported the histologic diagnoses. However, several gliomas had unusual histologic features and did not correspond to a well-defined entity. Molecular testing was essential for accurate classification of a subset of these tumors, and several high-grade gliomas exhibited fusions considered unique to infantile gliomas, including those involving the MET, ALK and NTRK genes. To our knowledge, this cohort represents the largest single-institution study of congenital CNS tumors and highlights many ways in which congenital CNS tumors are distinct from CNS tumors of older pediatric patients and adults.

Pineal Atypical Teratoid Rhabdoid Tumor in a 5-Month-Old Child

INTRODUCTION

Atypical teratoid rhabdoid tumors (ATRT), an uncommon malignant intracranial tumor with aggressive behavior are mostly seen in posterior fossa in young pediatric age-group.

CASE PRESENTATION

We present an infrequent location of this tumor in the pineal region in a 5-month-old infant. Also, the lesion was non-enhancing which was highly atypical of an ATRT. It was near-totally excised with the child placed in sitting position. However, within a short interval, a tumor recurrence was noted.

CONCLUSION

The case possibly represents an extended spectrum of congenital childhood brain tumors. Importantly, it highlights an atypical imaging of ATRT in very young children.

Perinatal (fetal and neonatal) choroid plexus tumors: a review

INTRODUCTION

The object of this review is to describe the choroid plexus tumors (CPTs) occurring in the fetus and neonate with regard to clinical presentation, location, pathology, treatment, and outcome.

MATERIALS AND METHODS

Case histories and clinical outcomes were reviewed from 93 cases of fetal and neonatal tumors obtained from the literature and our own institutional experience from 1980 to 2016.

RESULTS

Choroid plexus papilloma (CPP) is the most common tumor followed by choroid plexus carcinoma (CPC) and atypical choroid plexus papilloma (ACPP). Hydrocephalus and macrocephaly are the presenting features for all three tumors. The lateral ventricles are the main site of tumor origin followed by the third and fourth ventricles, respectively. CPTs of the fetus are detected most often near the end of the third trimester of pregnancy by fetal ultrasound. The extent of surgical resection plays an important role in the treatment and outcome. In spite of excellent survival, which is especially true in the case of CPP, surgical resection may carry significant risks in an immature baby. Given the neonatal low blood volume and increased vascularity of the tumors, there is potential risk for hemorrhage. Although advances in neurosurgical techniques have led to a greater degree of complete surgical resections, survival for the perinatal CPC group remains low even with multimodality therapies.

CONCLUSION

Perinatal CPTs have variable overall survivals depending on degree of surgical resection and tumor biology. An increased understanding of the molecular features of these tumors may lead to improved therapies and ultimately survival.

Management of fetal tumors

In this review article, we discuss the most common fetal tumors, their prenatal management, and outcomes. Overall, the most important outcome predictors are tumor histology, size, vascularity, and location. Very large lesions, lesions causing cardiac failure, and hydrops and lesions obstructing the fetal airway have the poorest outcome, as they may cause fetal death or complications at the time of delivery. Fetal therapy has been developed to improve outcomes for the most severe cases and can consist of transplacental therapy (sirolimus for rhabdomyomas or steroids for hemangiomas and microcystic lung lesions) or surgical intervention (shunting of cystic masses, tumor ablation, occlusion of blood flow or airway exploration, and protection). Given the rarity of fetal tumors, patients should be referred to expert centers where care can be optimized and individualized to allow the best possible outcomes.

Congenital Extra-Ventricular (Ganglio)Neurocytoma of the Brain Stem: A Case Report

Extraventricular neurocytoma (EVN) is an extremely rare tumor of neuroglial origin with a tendency toward ganglionic or glial differentiation. In the 2016 World Health Organization Classification, EVN was classified as a grade II tumor and described as a neoplasm with good outcome. However, the presence of cellular atypia is an important unfavorable prognostic factor. Here, we describe the first case of a patient with a congenital EVN localized in the brainstem. After a sub-total resection, his disease rapidly progressed despite several chemotherapies, including molecular targeting approaches. He died 13 months after diagnosis. In conclusion, we report an atypical case of EVN presenting an extremely aggressive behavior, despite the absence of cellular atypia. The brainstem origin and the age of the patient may have represented two important prognostic factors for our patient.

A Case of Congenital Brainstem Oligodendroglioma: Pathology Findings and Review of the Literature

Congenital and perinatal primary brain neoplasms are extremely rare. Brainstem neoplasms in the perinatal and neonatal period are typically of high-grade nature and have poor prognoses with survival rates of less than 2 years from diagnosis. Herein, we report an unusual case of congenital anaplastic oligodendroglioma that arose in the pons and was detected as diffuse pontine glioma on in utero imaging studies during prenatal evaluation at 26 weeks' gestation. A male infant was delivered at 36.4 weeks of gestation via Cesarean section who developed progressive dyspnea shortly after birth. Magnetic resonance imaging (MRI) studies of his head showed the expansile, poorly demarcated mass in the pons with minimal heterogeneous enhancement and severe communicating hydrocephalus. Despite aggressive management, including dexamethasone treatment, the infant expired on the third day of postnatal life. On postmortem examination cut sections through the brainstem and cerebellum disclosed the neoplasm that infiltrated the entire pons, extended into the midbrain, medulla, cerebellar peduncles, and caudal diencephalon. Histological sections demonstrated an anaplastic oligodendroglioma infiltrating the pons, 4th ventricle, midbrain, medulla, cerebellar white matter, posterior thalamus, and occipital white matter. The pathological features of the lesion distinguish it from previous reports in which spontaneous regression of pontine gliomas occurred and argue in favor of establishing a tissue diagnosis to plan for aggressive versus conservative management.

Congenital Glioblastoma with Distinct Clinical and Molecular Characteristics: Case Reports and a Literature Review

BACKGROUND

The molecular diagnosis of brain tumors is important in classifying tumors and determining appropriate treatment. Congenital glioblastoma multiforme (GBM) is a rare tumor that occurs in infants, and the prognosis is poor. Approximately 60 patients diagnosed with congenital GBM have been reported. However, few reports have conducted molecular analyses of congenital GBM.

CASE DESCRIPTION

We describe 2 congenital GBM patients treated in our hospital, and report results of immunohistochemistry, fluorescent in situ hybridization (FISH), direct sequencing, and methylation analyses. Surgery was performed on both patients at 2 months old, and the cases were diagnosed as glioblastoma. Immunohistochemical staining, FISH, and direct sequencing were positive for glial fibrillary acidic protein and ATRX, partially positive for p53, showed no alteration of isocitrate dehydrogenase 1 R132H, H3F3A, HIST1H3B, and BRAF, and indicated no codeletion of 1p and 19q. Methylation analysis of 1 patient identified copy number aberrations of 4 genes: deletions of CDK6 and CDKN2A/B, and a fusion of MET. One patient received chemotherapy consisting of ranimustine, interferon-beta, carboplatin, and etoposide, whereas the other patient received chemotherapy with the modified Children's Cancer Group study-9921 protocol. Residual tumors in both patients were decreased, and they achieved 18-year- and 9-month progression-free survival, respectively. In addition, we reviewed 65 previously reported congenital GBM patients, and found they have better prognosis than pediatric and adult GBM, and long-term survival can be expected.

CONCLUSIONS

Congenital GBM demonstrates clinical and molecular characteristics that are different from those of pediatric or adult GBM.

A rare case of congenital glioblastoma with atypical presentation in an eleven month-old infant: Case report with review of literature

Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumor in adults. The occurrence of this entity in infants is a rarity and portends a uniform dismal prognosis and survival in spite of all the latest available management options. The authors herein report a case of a GBM in an 11 month-old infant with tumor involving predominantly the left temporal and frontal regions who expired 10 weeks after tumor decompression. Literature and available management options have been reviewed in the context of the presented case.

Diffusion, Perfusion, and Histopathologic Characteristics of Desmoplastic Infantile Ganglioglioma

We present a case series of a rare tumor, the desmoplastic infantile ganglioglioma (DIG) with MRI diffusion and perfusion imaging quantification as well as histopathologic characterization. Four cases with pathologically-proven DIG had diffusion weighted imaging (DWI) and two of the four had dynamic susceptibility contrast imaging. All four tumors demonstrate DWI findings compatible with low-grade pediatric tumors. For the two cases with perfusion imaging, a higher relative cerebral blood volume was associated with higher proliferation index on histopathology for one of the cases. Our results are discussed in conjunction with a literature review.

Identification of ZCCHC8 as fusion partner of ROS1 in a case of congenital glioblastoma multiforme with a t(6;12)(q21;q24.3)

Congenital gliobastoma multiforme (GBM) is rare and little is known about the molecular defects underlying the initiation and progression of this tumor type. We present a case of congenital GBM analyzed by conventional cytogenetics, fluorescence in situ hybridization, array comparative genomic hybridization and next generation sequencing. On cytogenetic analysis we detected a reciprocal translocation t(6;12)(q21;q24.3). By sequencing, the translocation was shown to form a fusion between the 5' region of ZCCHC8 and the 3' region of ROS1. RT-PCR analyses confirmed the existence of an in-frame fusion transcript with ZCCHC8 exons 1-3 joined to ROS1 exons 36-43. In addition to the ZCCHC8-ROS1 fusion, we detected a deletion in the short arm of chromosome 9, including homozygous loss of the CDKN2A/2B locus in 9p21.3 and heterozygous deletion of the HAUS6 gene in 9p22.1. The latter encodes a protein involved in faithful chromosome segregation by regulating microtubule nucleation and its deletion might be associated with the marked subclonal changes of ploidy observed in the tumor. This report adds the ZCCHC8-ROS1 fusion as oncogenic driver in GBM and supports the role of ROS1 activation in the pathogenesis of a subset of GBM. © 2016 Wiley Periodicals, Inc.

Perinatal (fetal and neonatal) astrocytoma: a review

INTRODUCTION

The purpose of this review is to document the various types of astrocytoma that occur in the fetus and neonate, their locations, initial findings, pathology, and outcome. Data are presented that show which patients are likely to survive or benefit from treatment compared with those who are unlikely to respond.

MATERIALS AND METHODS

One hundred one fetal and neonatal tumors were collected from the literature for study.

RESULTS

Macrocephaly and an intracranial mass were the most common initial findings. Overall, hydrocephalus and intracranial hemorrhage were next. Glioblastoma (GBM) was the most common neoplasm followed in order by subependymal giant cell astrocytoma (SEGA), low-grade astrocytoma, anaplastic astrocytoma, and desmoplastic infantile astrocytoma (DIA). Tumors were detected most often toward the end of the third trimester of pregnancy.

CONCLUSION

A number of patients were considered inoperable since their tumor occupied much of the intracranial cavity involving large areas of the brain. High-grade astrocytomas were more common than low-grade ones in this review. Fetuses and neonates with astrocytoma have a mixed prognosis ranging from as low as 20 % (GBM) to a high of 90 %. The overall survival was 47/101 or 46 %.

Medical and ethical challenges in the case of a prenatally undiagnosed massive congenital brain tumor

Fetal and neonatal brain tumors are rare. Prenatal ultrasound aids early tumor detection. Nonetheless, we encountered a preterm neonate born at 32 weeks gestation with a massive supratentorial glioma, which was undetected on ultrasound at 19-6/7 weeks gestation. The patient presented at birth with unanticipated massive macrocephaly. Resuscitation and stabilization were difficult, but the medical team felt that futility of care was not established and opted to transfer the baby to an academic center for further imaging and specialist consultations. Diagnosis of an extensive, inoperable tumor was confirmed and support withdrawn. Postmortem histologic examination and immunohistochemical stains identified the majority of tumor cells as glial in origin. This case report illustrates well how a severe and potentially fatal anomaly, which remained undetected prenatally, presented the medical team and family with multiple medical, ethical and emotional challenges at birth; decisions regarding futility of care in the neonatal transport setting are difficult.

A case of congenital brain teratoma extending into the orbit

Congenital tumors arising from the central nervous system are uncommon. A 31-year-old pregnant woman had an uneventful course until 33 weeks of gestation (GW). An ultrasonographic examination at 35 GW first demonstrated an increase in fetal head size. The brain midline shifted to the left side due to the intracranial tumor extending into the orbit in the right hemisphere at 36 GW. The brain teratoma in the fetus was suspected by magnetic resonance imaging of the heterogeneous enhancement and calcification. The male baby was delivered by cesarean section at 36 GW and he had facial dimorphism with right exophthalmos. The tumor volume continued to increase after surgery and the baby died at 123 days of life.

Synchronous congenital malignant rhabdoid tumor of the orbit and atypical teratoid/rhabdoid tumor--feasibility and efficacy of multimodal therapy in a long-term survivor

Among infant malignancies, congenital tumors, especially those of the central nervous system (CNS), constitute a rather unique subgroup. Poor survival rates (28% in CNS tumors) may be attributed to the aggressive biology as well as specific therapeutic limitations innate to the young age of affected patients. Our patient developed synchronous congenital tumors: an atypical teratoid/rhabdoid tumor (AT/RT) localized in the right lateral ventricle of the brain and a malignant rhabdoid tumor (MRT) in the soft tissue of the right orbit. A de novo germline chromosomal deletion in 22q encompassing the SMARCB1 gene was detected, prompting the diagnosis of a de novo rhabdoid tumor predisposition syndrome 1 (RTPS1). The patient was reported to the European Rhabdoid Registry (EU-RHAB) and treated according to the Rhabdoid 2007 recommendation. Despite the very young age of the patient, the initially desperate situation of RTPS1, and the synchronous localization of congenital rhabdoid tumors, intensive chemotherapy was well tolerated; the child is still in complete remission 5 years following diagnosis. In conclusion, RTPS1 with congenital synchronous MRTs is not necessarily associated with a detrimental outcome. Intensive multidrug chemotherapy, including high dose chemotherapy, may be feasible and justified.

A case of intrauterine diagnosed posterior fossa dermoid presenting in childhood

Intrauterine intracranial brain tumor is a rare entity. Traditionally, the outcome of this tumor had been dismal. In a large series of congenital brain tumor, the commonest have been teratoma followed by astrocytoma and craniopharyngioma. We report a case of intracranial dermoid in post-fossa diagnosed at 8 months of intrauterine life during routine prenatal ultrasonography. The child's clinical picture, the surgery performed and the final outcome have been discussed. As far as our knowledge goes, this is perhaps the first reported case of intrauterine-diagnosed intracranial dermoid.

Fetal growth and childhood cancer: a population-based study

OBJECTIVE

The etiology of childhood cancers is largely unknown. Studies have suggested that birth characteristics may be associated with risk. Our goal was to evaluate the risk of childhood cancers in relation to fetal growth.

METHODS

We conducted a case-control study nested within Nordic birth registries. The study included cancer cases diagnosed in Denmark, Finland, Norway, and Sweden among children born from 1967 to 2010 and up to 10 matched controls per case, totaling 17,698 cases and 172,422 controls. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were derived from conditional logistic regression.

RESULTS

Risks of all childhood cancers increased with increasing birth weight (P trend ≤ .001). Risks of acute lymphoid leukemia and Wilms tumor were elevated when birth weight was >4000 g and of central nervous system tumors when birth weight was >4500 g. Newborns large for gestational age were at increased risk of Wilms tumor (OR: 2.1 [95% CI: 1.2-3.6]) and connective/soft tissue tumors (OR: 2.1 [95% CI: 1.1-4.4]). In contrast, the risk of acute myeloid leukemia was increased among children born small for gestational age (OR: 1.8 [95% CI: 1.1-3.1]). Children diagnosed with central nervous system tumors at <1 year of age had elevated risk with increasing head circumference (P trend < .001). Those with head circumference >39 cm had the highest risk (OR: 4.7 [95% CI: 2.5-8.7]).

CONCLUSIONS

In this large, Nordic population-based study, increased risks for several childhood tumors were associated with measures of fetal growth, supporting the hypothesis that tumorigenesis manifesting in childhood is initiated in utero.

Central nervous system tumors in the first year of life: a clinical and pathologic experience from a single cancer center

PURPOSE

This study aims to review our experience with central nervous system (CNS) tumors occurring during the first year of life and to report differing features found in our series.

METHODS

This is a retrospective study of infants with CNS tumors diagnosed at our institution from 2006 to 2011.

RESULTS

A total of 19 cases were identified, with a median age of 232 days and predominance of male gender. Males were younger than females at the time of diagnosis (p value = 0.039). There were 13 low-grade tumors, glial tumors being the most common (11/13, p value = 0.003) and six high-grade tumors, atypical teratoid rhabdoid tumor being the most common (4/6). Low-grade tumors predominated in the supratentorial region, while high-grade tumors were seen in the infratentorial area (p value = 0.035). Males had a predilection to have more supratentorial tumors (p value = 0.058). Four patients underwent gross total resection, and eight received chemotherapy; none received radiotherapy. Two patients had spinal cord tumors; both were of pilomyxoid astrocytoma histology. Rare tumors included hemangiopericytoma (n = 1) and atypical choroid plexus tumor (n = 1), both occurring in the supratentorial area and affecting the youngest patients in this group; they were diagnosed prenatally and at 107 days, respectively. The median progression-free and overall survivals were 269 and 667 days, respectively. Among all tested parameters, only the grade of the tumor affected the outcome.

CONCLUSIONS

Diagnosis and management of infant's CNS tumors remain challenging. Pathologists should be aware of the diversity of histological types. Assigning appropriate tumor grade is fundamental in predicting the outcome.

Epidemiology of primary brain tumors in childhood and adolescence in Kuwait

The relatively high frequency of primary brain tumors (PBT) observed in childhood and adolescence in Kuwait has necessitated this epidemiological study. It is based on the records of the Department of Pathology, Al-Sabah Hospital, which examined all brain tumor biopsies done in this age group in Kuwait between 1995 and 2011. During this period, 75 boys (49%) boys and 77 (51%) girls had histologically confirmed PBT. They comprised 122 children (0-14 years) and 30 adolescents (15-19 years). The boys/girls ratio was 1.03 in childhood and 0.76 in adolescence. The age-adjusted incidence rate was 11.2/ million person-years. Early childhood (0-4 years) had the peak frequency of tumors (33%), highest adjusted age-specific incidence rate (3.8/million person-years) of all tumors and the least boys/girls rates ratio (0.38) for astrocytic tumors. Low grade and high grade tumors peaked in 5-9 and 0-4 years respectively. Risk factors (hereditary syndromes or previous radio-therapy) were identified in three patients. Three (2%) tumors were congenital. High grade tumors comprised 47% of childhood and 23% of adolescence PBT. The most common tumors in childhood were astrocytoma (37%), embryonal tumors (31%), ependymoma (8%), and in adolescence astrocytoma (27%), pituitary adenoma (23%) and glioblastoma (13%). Embryonal tumors formed 44% of PBT in early childhood. Gliomas constituted 54% and 43% of all PBT, but 25% and 57% of high grade tumors in childhood and adolescence respectively. Most common tumor locations were cerebellum (47%), ventricles (19%) and cerebral lobes (17%) in childhood and pituitary (30%), cerebellum (27%) and 13% each for cerebral lobes and ventricles in adolescence. Approximately 57% of childhood and 23% of adolescence PBT were infratentorial. In conclusion, despite the high relative frequency of PBT before the age of 20 years in Kuwait, its incidence rate is apparently low. Compared with Western countries, Kuwait has a lower incidence of malignant gliomas, but a higher frequency of cerebellar and intraventricular tumors. Embryonal tumors are remarkably common in early childhood.

Clinical and molecular characteristics of congenital glioblastoma

Congenital glioblastoma (cGBM) is an uncommon tumor of infancy with a reported variable but often poor cure rate, even with intensive therapy. Five patients with cGBMs, arising de novo and not in familial tumor predisposition kindreds, were studied for histological and biological features, using Affymetrix microarray. Tumors were large, often associated with hemorrhage, extended into the thalamus, and often bulged into the ventricles. One patient died acutely from bleeding at the time of operation. The 4 surviving patients underwent surgery (1 gross total resection, 3 subtotal resections or biopsies) and moderate intensity chemotherapy without radiation, and remain progression-free at a median time of 36 months (range, 30-110 months). Affymetrix microarrays measured gene expression on the 3 cGBMs from which frozen tissue was available. Unsupervised hierarchical clustering of cGBMs versus 168 other central nervous system tumors demonstrated that cGBMs clustered most closely with other high-grade gliomas. Gene expression profiles of cGBMs were compared with non-congenital pediatric and adult GBMs. cGBMs demonstrated marked similarity to both pediatric and adult GBMs, with only 31 differentially expressed genes identified (false discovery rate, <0.05). Unique molecular features of cGBMs included over-expression of multiple genes involved in glucose metabolism and tissue hypoxia. cGBMs show histological and biological overlap with pediatric and adult GBMs but appear to have a more favorable outcome, with good response to moderate intensity chemotherapy with only subtotal resection or biopsy. Further study may determine whether identified gene expression differences contribute to the improved survival seen in these tumors.

Magnetic resonance microscopy at 14 Tesla and correlative histopathology of human brain tumor tissue

Magnetic Resonance Microscopy (MRM) can provide high microstructural detail in excised human lesions. Previous MRM images on some experimental models and a few human samples suggest the large potential of the technique. The aim of this study was the characterization of specific morphological features of human brain tumor samples by MRM and correlative histopathology. We performed MRM imaging and correlative histopathology in 19 meningioma and 11 glioma human brain tumor samples obtained at surgery. To our knowledge, this is the first MRM direct structural characterization of human brain tumor samples. MRM of brain tumor tissue provided images with 35 to 40 µm spatial resolution. The use of MRM to study human brain tumor samples provides new microstructural information on brain tumors for better classification and characterization. The correlation between MRM and histopathology images allowed the determination of image parameters for critical microstructures of the tumor, like collagen patterns, necrotic foci, calcifications and/or psammoma bodies, vascular distribution and hemorrhage among others. Therefore, MRM may help in interpreting the Clinical Magnetic Resonance images in terms of cell biology processes and tissue patterns. Finally, and most importantly for clinical diagnosis purposes, it provides three-dimensional information in intact samples which may help in selecting a preferential orientation for the histopathology slicing which contains most of the informative elements of the biopsy. Overall, the findings reported here provide a new and unique microstructural view of intact human brain tumor tissue. At this point, our approach and results allow the identification of specific tissue types and pathological features in unprocessed tumor samples.