[Role of adjuvant chemotherapy in the treatment of medulloblastoma in children]

A retrospective review was carried out to evaluate the results of treatment (1989-1998) of 81 children, aged under 15, with primary medulloblastoma. Thirty-three patients received surgery and postoperative craniospinal radiotherapy; 48--adjuvant chemotherapy (VCR 1.5 mg/m2, i.v., 1 day; CCNU 75 mg/m2, per os, 1 day; cisplatin 80 mg/m2 or carboplatin 400 mg/m2, i.v., 1 day). Overall 9-year survival was 37 +/- 0.8%. This index in the adjuvant chemotherapy group was 59 +/- 0.8%, without chemotherapy--22 +/- 0.8%.

Results of three-dimensional stereotactically-guided radiotherapy in recurrent medulloblastoma

PURPOSE

To evaluate survival rates and side effects after stereotactically-guided radiotherapy (SRT) in patients with recurrent medulloblastoma of the brain.

METHODS AND MATERIALS

Between 1992 and 2000, 20 patients with 29 radiological manifestations were treated with fractionated SRT (n = 21) or radiosurgery (n = 8). Median age was 16 years with 6 patients < or = 14 years. All patients had prior cranio-spinal radiotherapy plus boost to the posterior fossa with a total dose of 54 Gy. Time to recurrence was 33 months mean. Eighteen of the 29 lesions were located within the boost volume. Chemotherapy was given according to current international study protocols (HIT) in all patients. Mean total dose for re-irradiation was 24 Gy for fractionated stereotactically-guided radiotherapy, and 15 Gy for radiosurgery. Mean follow-up was 88.5 months.

RESULTS

Overall local control was 89.7%. Thirteen recurrences showed partial or complete response in CT/MR-imaging, 13 showed stable disease. Local tumor progression was seen 5 months mean after radiotherapy in three cases. A multifocal intracranial progression was seen in 9 patients, 5 patients developed additional spinal metastases. Thirteen patients died with disseminated cranio-spinal progression, after 72.6 months median. No late toxicity > CTC II(o) especially no brain radionecrosis was seen after radiotherapy.

CONCLUSION

SRT is effective and safe in the treatment of recurrent medulloblastoma to improve local control without evident side effects. The main problem remains the control of subclinical cranio-spinal dissemination.

Recent advances in paediatric neuro-oncology

PURPOSE OF REVIEW

Primary central nervous system malignancies incorporate a variety of tumours with diverse biology and clinical behaviour and represent the most common solid tumour entity of childhood, accounting for approximate 20-25% of all primary paediatric malignancies. Recent findings regarding the underlying tumour biology may open up new avenues of clinical trial design, particularly identifying possible targets for biological modifiers. Over the last 12-18 months a significant number of institutional and national studies have been reported which are likely to impact on the design of future clinical trials.

RECENT FINDINGS

In low-grade gliomas, stereotactically guided conformal radiotherapy should lead to a significant reduction in radiation-associated late toxicity, while in selected groups of high-grade gliomas the use of adjuvant or neo-adjuvant chemotherapy may improve survival. Completeness of resection and use of adjuvant focal radiotherapy remains the most important prognostic factor for outcome in patients with ependymomas, although in infants the use of post-surgical chemotherapy alone may allow the postponing of radiotherapy in selected cases. In primitive neuroectodermal tumours prognostic biological markers have been identified that are undergoing prospective evaluation. For patients with localized medulloblastomas a new standard treatment is emerging that uses reduced-dose craniospinal radiotherapy followed by platinum-based chemotherapy, while in supratentorial primitive neuroectodermal tumours future treatment will be aimed at improving local control.

SUMMARY

Given the rarity of paediatric primary central nervous system malignancies, further progress can only be achieved in the context of national or multinational prospective clinical trials incorporating biological studies, and participation in these should be strongly encouraged.

[Lumbar meningeal enhancement after surgery in the posterior cranial fossa: a normal finding in children?]

PURPOSE

Spinal meningeal Gd-DTPA enhancement after cranial surgery is a known observation of a not well understood underlying mechanism. This paper demonstrates that this MRI finding is a normal meningeal reaction to subarachnoid hemorrhage, which should not be mistaken for metastatic spread.

MATERIAL AND METHODS

Three pediatric patients were examined by MRI for metastatic spread of malignant infratentorial tumors along the spinal canal two to nine days after the removal of the primary cerebral lesion. The findings were compared with a control group that underwent cranial surgery (cyst resection or fenestration of the posterior cranial fossa) without major bleeding into the subarachnoid space. Unenhanced and enhanced sequences were obtained to prove that the high signal within the CSF is caused by an abnormal Gd-DTPA uptake and not by methemoglobin.

RESULTS

Meningeal enhancement was observed in all patients with intraoperative bleeding resembling subarachnoid masses on enhanced T 1 -weighted images. This was not present in any patient of the control group. This finding lasts for approximately two weeks.

CONCLUSION

The meningeal enhancement renders immediate postoperative studies inconclusive for the detection of metastatic spread. Consequently, the obligatory tumor staging along the spinal canal should ideally be done prior to the resection of a cerebral tumor.

Medulloblastoma or cerebellar dysplastic gangliocytoma (Lhermitte-Duclos disease)?

Dysplastic cerebellar gangliocytoma is a rare benign tumor associated with specific neuroimaging findings of abnormal laminated or folial pattern in the posterior fossa. Some authors thus proposed that it could be diagnosed by neuroimaging studies alone. We encountered a patient with medulloblastoma in which the neuroimaging findings mimicked those of dysplastic gangliocytoma. In patients with a posterior fossa tumor suggestive of a dysplastic gangliocytoma on neuroimaging studies, a pathologic confirmation is necessary.

Medulloblastoma in adults: treatment results and prognostic factors

PURPOSE

To investigate the treatment outcome and prognostic factors of adult medulloblastoma patients who received postoperative craniospinal irradiation (RT).

METHODS AND MATERIALS

Between 1983 and 2000, 30 adult patients (17 men and 13 women, age >or=16 years, median 27, range 16-45) underwent postoperative RT. The median duration of symptoms was 2 months (range 1-9). The tumor location was lateral in 16 (53%). A desmoplastic variant was seen in 12 (40%). Tumor resection was complete in 20 (67%) and incomplete in 10 (33%). All patients received craniospinal RT. The median dose to the whole brain was 40 Gy (range 36-51), to the posterior fossa 54 Gy (range 49-56), and to the spinal axis 36 Gy (range 24-40). The median interval between surgery and the start of RT was 31 days (range 12-69), and the median duration of RT was 45 days (range 34-89). Ten patients (33%) received adjuvant chemotherapy. The median follow-up was 51 months (range 5-215).

RESULTS

The 5- and 8-year overall survival and disease-free survival rates were 65% and 51% and 63% and 50%, respectively. Twelve patients (40%) developed relapse, with a median follow-up of 51 months. The posterior fossa was the most common site of relapse (6 patients). The median time to relapse was 26 months (range 4-78). Fifty percent of the relapses occurred after 2 years, 17% after 5 years. In univariate analysis, M stage and the interval between surgery and the start of RT were significant prognostic factors for disease-free survival. At 5 years, 70% of M0 patients were estimated to be disease-free, but none of the 3 M3 patients reached 5 years without recurrence (p = 0.0002). The 5-year disease-free survival rate for the patients whose interval between surgery and the start of RT was <3 weeks, between 3 and 6 weeks, and >6 weeks was 0%, 85%, and 75%, respectively (p = 0.002). The 5-year posterior fossa control rate for patients who received >or=54 Gy or <54 Gy to the posterior fossa was 91% and 33%, respectively (p = 0.05).

CONCLUSION

The survival results for medulloblastomas in adults compare favorably with those in children. However, late relapses, lateral tumor location, and desmoplastic histologic features are more frequent in adults. Spinal seeding at presentation is a poor prognostic factor for disease-free survival. A minimal dose of 54 Gy to the posterior fossa is essential for adequate tumor control. The interval between surgery and the start of RT, which was found to be a significant prognostic factor, is an interesting issue that requires further study.

Clinical and survival covariates of eight classes of childhood supratentorial neuroglial tumors

BACKGROUND

In the current study, the authors investigated clinical, surgical, and histologic characteristics (covariates) and their interactions in eight previously identified classes of childhood supratentorial neuroglial tumors. The classes resulted from 5 factor score profiles on 703 supratentorial neuroglial tumors in the Childhood Brain Tumor Consortium database.

METHODS

The Cox proportional models were used to identify class survival covariates.

RESULTS

Age was found to be a survival covariate only in Class 1, in which older age increased the 5-year survival rate 73% from the first year (0.49) to the tenth year (0.85). A greater amount of tumor removed improved survival in Classes 2 and 4 only. Rosenthal fibers improved survival in Class 2 and overrode the negative effects of high Proliferative factor scores and pleomorphic nuclei. Survival for Class 3 children with high Proliferative factor scores improved from 0.60 to 0.95 as the Spongy factor scores increased. Survival in Class 4 increased from 0.17 to 0.39 with total tumor removal. Irregular nuclei and glomeruloid capillaries improved survival in Class 5 patients. Class 6 survival improved with low cell density. Macrocysts in tumors in Classes 1 and 5 were found to improve survival.

CONCLUSIONS

As a result of the current study, the authors conclude that survival covariates differ with tumor class and may modify prognosis considerably.

Intraoperative hemorrhage in medulloblastoma: a case report and review of the literature

OBJECT

We present the first case of intraoperative hemorrhage in a medulloblastoma.

CASE REPORT

A 10-year-old girl presented with a 4-week history of headache, nausea, and vomiting. Radiological examination showed a space-occupying mass in the cerebellar vermis. Surgical removal was performed via a midline suboccipital approach. When the dura was incised and the occipital sinus was ligated after suboccipital craniectomy, bleeding occurred in the tumor. Macroscopically, hematoma was found only in the left part of the tumor and not in the right part. Microscopically, different architectures of tumor vessels, thin-walled and thick-walled, were found between the left part and the right part, respectively. The tumoral contents and hematoma were totally removed. Histological examination revealed a medulloblastoma.

CONCLUSION

We experienced a very rare case of medulloblastoma in which intratumoral hemorrhage occurred during operation. We speculate that ligation of the occipital sinus and thin-walled vessels within the tumor might have caused the hemorrhage in our case.

Novel multipurpose bipolar instrument for endoscopic neurosurgery

OBJECTIVE

Hemorrhage control in endoscopic neurosurgery is critical because of the lack of suitable instruments for coagulation. One reason for this problem is that miniaturization of the instruments is still a technical problem. In this article, we present a solution: the use of bipolar microforceps with a small diameter of 1.5 mm.

METHODS

With the use of modern synthetic and metallic materials, the construction of the bipolar microforceps was designed without the use of mechanical joints. All movable elements are integrated within the instrument shaft. This design provides optimal visibility of the operating field because the sheath has a diameter of only 1.5 mm along its entire length. Therefore, this instrument is compatible with most working channels of neuroendoscopes.

RESULTS

The new, joint-free design of the forceps and the electric insulation of the branches were the technical innovations that led to the development of this novel, multipurpose instrument.

CONCLUSION

This new instrument may enhance endoscopic resection and shrinkage of cystic lesions and may offer new possibilities in endoscopic tumor resection and the treatment of hemorrhage.

[Neuroradiological differential diagnosis in medulloblastomas and ependymomas: results of the HIT'91-study]

BACKGROUND

Imaging criteria of medulloblastomas and ependymomas were defined retrospectively to allow a preoperative differential diagnosis of these malignant tumors of the posterior fossa.

PATIENTS AND METHODS

CT and/or MR-studies of 103 patients with medulloblastomas and 19 ependymomas treated in the HIT'91-trial were centrally reviewed. Evaluation concerned the origin, CT-density or MR-signal intensity, enhancement, internal structural homogeneity and results of staging of the tumors.

RESULTS

Medulloblastomas and Ependymomas showed different results concerning all imaging criteria.

CONCLUSION

On the basis of differences in localisation, enhancement and tumor growth in most cases a preoperative differential diagnosis between medulloblastomas and ependymomas is possible. Increased density on CT allows the differentiation of the malignant tumors from pilocytic astrocytomas of the fourth ventricle.

Familial medulloblastoma: case report of one family and review of the literature

OBJECTIVE AND IMPORTANCE

Medulloblastoma is the most common malignant brain tumor and the most common malignant solid tumor in children. Most medulloblastomas are sporadic, but rare familial forms have been described. To the best of our knowledge, only 10 case reports of familial medulloblastoma have been published. A variety of candidate genes have been suggested to be involved in familial medulloblastomas. However, the exact pathogenesis and genetics involved in familial medulloblastoma remain unknown.

CLINICAL PRESENTATION

We describe the presentation of medulloblastoma in two siblings (one of each sex) and their great-uncle. The three cases differ with regard to age at onset and pathological subtype of medulloblastoma. INTERVENTION OR TECHNIQUE: Immunostaining of tissue blocks for gene products involved in medulloblastoma differed in the two siblings for beta-catenin and was similar with staining for gli.

CONCLUSION

This article is only the second report in the literature to address the genetics of familial medulloblastoma in the absence of characterized conditions such as Li-Fraumeni's cancer syndrome and basal cell nevus, Rubinstein-Taybi's, and Turcot's syndromes. The discrepancy in beta-catenin staining in the two siblings suggests that the two tumors differentiated through divergent pathways. We briefly summarize all published cases of familial medulloblastoma and review the literature on the genes involved in medulloblastoma formation.

Pharmacology review: the role of ondansetron in the management of children's nausea and vomiting following posterior fossa neurosurgical procedures

The management of nausea and vomiting is fundamental to the post-operative nursing care of children. Children who have neurosurgical procedures, especially those that involve the posterior fossa, are likely to experience nausea and vomiting in the post-operative period. The proximity of brainstem emetic centres to the surgical site compounds the usual post-operative risk factors for nausea and vomiting. Ondansetron is discussed as an agent that may be more effective than the traditionally-used antiemetics, such as dimenhydrinate and metoclopramide, in this population. Nurses must advocate for effective therapeutic measures to manage children's post-operative nausea and vomiting. Advocacy requires knowledge of high-risk groups, accurate assessment, timely intervention, and thorough evaluation of pharmacological and non-pharmacological measures.

[Clinical application of proton magnetic resonance spectroscopy for differential diagnosis of pediatric posterior fossa tumors]

We report here on a correlation between proton magnetic resonance spectroscopy (MRS) spectra obtained in children with posterior fossa tumors and tumor histology and grading. Twenty-six children (age 1-16) were investigated before surgery by using single-voxel proton MRS. All examination were performed on a 1.5 T MR scanner by using single-voxel (8 cm3) with PRESS sequence (TR 1600 ms, TE 270 ms, NEX 256). Spectra of N-acetylaspartate (NAA), choline containing compounds (Cho), creatine and phosphocreatine (Cr) and lactate (Lac) were evaluated. Absolute concentrations of the metabolites were measured and their ratios were calculated. Correlation between these and tumor histology and grading were then determined. Concentration of Cho and Lac, and Cho/NAA ratio were the major statistically significant parameters for discrimination between benign (WHO grade I and II) and malignant tumors (WHO grade III and IV), in particular between pilocytic astrocytomas and medulloblastomas. Discrimination between individual histological types within malignant and benign tumor groups was not possible. Proton MRS of pediatric posterior fossa tumors seems to be helpful in prediction of tumor grading and histology. Specific character of the examination requires establishing of the individual standards for every MR scanner.

Postoperative radiation therapy for medulloblastoma--high recurrence rate in the subfrontal region

PURPOSE

To investigate the treatment results and analyze the prognostic factors for patients with medulloblastoma (MB) treated by surgery and postoperative radiation therapy (RT).

METHODS AND MATERIALS

Thirty-five patients of MB receiving surgery followed by RT from February 1986 to September 1999 were reviewed. Their median age was 12 years with a slight male predominance. Twenty-four (69%) patients had total resection of tumor. Most (86%) cases received craniospinal irradiation (CSI). Adequate dose (craniospinal dose > 30 Gy and posterior fossa dose > or = 50 Gy) was given in 26 (74%) patients.

RESULTS

The median survival duration was 48 months. The 5-year and 10-year overall survival rates were 63% and 40%, respectively. Univariate analysis revealed that stage, shunt surgery, RT dose, and protracted RT course were significant factors in predicting overall survival (OS), disease-free survival (DFS), and/or posterior fossa control (PFC). Multivariate analysis showed that RT dose affected OS and PFC independently, stage influenced OS and DFS, while protracted RT course impacted DFS. A total of 20 cases developed disease relapse. The median time to relapse was 18 months. The posterior fossa (10 cases) was the most common site of first failure, followed by the subfrontal lobe (7 cases), spine (6 cases), and other areas (4 cases).

CONCLUSION

Our results were compatible with others, except that more subfrontal relapses were found. Surgical resection followed by standard dose and adequate margin of CSI are recommended as the mainstays of treatment.

Medulloblastomas in neurofibromatosis type 1. Case report and literature review

A 6-year-old girl, previously diagnosed with neurofibromatosis type 1 (NF-1) presented with ataxia and symptoms of raised intracranial pressure. Diagnostic work up disclosed a posterior fossa tumor. Histopathological study of the excised neoplasm showed a cerebellar medulloblastoma. We review the current literature and suggest that the association of medulloblastoma with NF-1 is not a chance occurrence, and that it might be pathogenically related. We propose that medulloblastoma should be added to the list of malignancies that are apt to occur in NF-1.

Petrosal presigmoid approach to the petro-clival and anterior cerebellopontine region (extended retrolabyrinthine, transtentorial approach)

Intradural tumours affecting the clivus may be divided into three categories depending the area primarily involved by tumour. The second area extends from the spheno-occipital synchondrosis to the level of the jugular foramina. This area is best approached through the petrosal approach and suited for patients with serviceable hearing on the side of the lesion. 35 cases having skull base lesions were operated by the Skull Base Surgery Group of Ege University Medical Faculty between October 1993 and December 1997. 8 out of 35 cases having the intradural tumours affecting the petroclival and anterior cerebellopontine region, the petrosal presigmoid approach was performed in 4 patients. As hearing was absent in another 4 patients, the translabyrinthine route was coupled a the petrosal craniotomy (transtemporal approach). The aim of this article is to highlight the definitions, indications, hints and pitfalls of the approach from the otoneurological point of view.

Pseudomigraine with prolonged aphasia in a child with cranial irradiation for medulloblastoma

We report a 12-year-old child with episodes of migraine-like headaches with visual and motor auras a year after the surgical resection and radiation therapy for medulloblastoma The patient presented with an episode of headache, prolonged aphasia, right hemiparesis, status epilepticus, and salt wasting. There was no evidence of a structural lesion. The neurologic deficits resolved over a period of 6 weeks. Because of the progressive deterioration in neurologic deficits, the patient underwent an extensive battery of laboratory tests and multiple neuroimages, all of which were normal. The unusually prolonged neurologic deficit in this patient without demonstrable structural lesions and his eventual complete recovery were most likely caused by ischemia in the left hemisphere secondary to vasospasm. This presentation mimics migraine headache. Evidence suggesting that this represents a long-term complication of treatment of children with central nervous system neoplasia is presented.

Survival of children under 3 years old with medulloblastoma: a study from the Mexican Cooperative Group for Childhood Malignancies (AMOHP)

BACKGROUND

The prognosis of medulloblastoma in children under 3 years of age is poor.

METHODS

A retrospective analysis was performed to evaluate children under 3 years of age with medulloblastoma. Overall survival (OS) and progression-free survival (PFS) were assessed in children with and without metastasis.

RESULTS

A total of 534 children were diagnosed with medulloblastoma during the study period, 49 (9.1%) of whom were under 3 years of age and were evaluated. Their ages ranged from 5 to 35 months with a mean of 18.5 months. In 39 (79.6%) of these patients the tumors were staged as T3M0 or under, while 10 (20.4%) had metastasis at diagnosis. The OS was 38% and PFS 37% in the whole series, while PFS was 32% in those with metastasis and 40% in those without ( P=0.78). For those who received radiotherapy the PFS was 62%, and in those not treated with radiotherapy PFS was nil ( P=0.0001). When the children were divided into those who received surgical treatment plus chemotherapy and those who received surgery plus radiotherapy plus chemotherapy, the PFS was nil and 66%, respectively ( P=0.00001).

CONCLUSION

Because of the high morbidity of radiotherapy in children under 3 years old, surgery continues to be the basis of improved prognosis, followed by chemotherapy.

Evolution of malignant cerebellar astrocytoma at the site of a treated medulloblastoma: report of two cases

The authors report two unusual cases in which a malignant astrocytoma developed at the site of the excision of an earlier medulloblastoma. While the precise etiology of these astrocytic tumours was unproven, theories of the origins of the second tumours, particularly in relation to the basic nature of medulloblastomas, are discussed.

Postoperative radiotherapy of childhood medulloblastomas

The purpose of this work is to review the result of radiotherapy in the treatment of medulloblastoma in pediatric patients. Between 1986 and 1998, 66 children (45 boys and 21 girls) received postoperative irradiation in our institute. Their mean age was 8.29 years. Irradiation was performed by linear accelerator, 36 Gy were applied in the high risk group (partial tumor resection, tumor cell positivity in the liquor, metastases within the central nervous system) and 30 Gy in the low risk group (total tumor resection, negative liquor cytology, no metastases within the central nervous system) on the entire cerebrum and spinal cord. This was followed in both groups by the application of 20-20 Gy boost irradiation on the posterior scala. Studying the survival it has been found that the surgical radicality did not significantly influence the survival chances of patients, however, with the increase in the tumor size the survival chance significantly decreases (p = 0.03). When predicting life expectancy, however, the stage of tumor, the age of patients, the risk group and the M stage yielded essential information. At the age of 8 years and less, the rate of survivors is 67.6%, for those over 8 years is 75.9% (p = 0.21), however the younger age was not significant. The appearance of metastases considerably deteriorates the chances of survival (from 81.5% to 66.7%, p = 0.02). In the low risk group of patients the 5-year survival is 80%, while in the high risk group it is significantly lower, 67.4% (p = 0.04).

Is the sitting or the prone position best for surgery for posterior fossa tumours in children?

BACKGROUND

The aim of this study was to compare complications in children operated for posterior fossa tumours in the sitting position with those in the prone position.

METHODS

We retrospectively assessed the perioperative course of posterior fossa tumour (PFT) surgery according to the operating position. Sixty children were operated in the sitting position (SP) and 19 in the prone position (PP). Preoperative data were not different between groups.

RESULTS

Patients in the PP group received a larger median (95% confidence interval) volume of intraoperative blood transfusion than patients in the SP group [200 (20-325) versus 0 (0-80) ml, P=0.04]. Intraoperative complications, as well as severe perioperative complications were more frequent in the PP group (P=0.01). The median duration of tracheal intubation [20 (18-24) versus 36 (18-72) h, P=0.037], of ICU stay [2 (2-3) versus 4 (2-5) days, P=0.02] and of hospital stay [11 (9-12) versus 14 (10-20) days, P=0.02] was longer in the PP group compared with the SP group.

CONCLUSIONS

PFT surgery in the sitting position in children is not associated with an increased number or severity of perioperative complications, while the postoperative course appears better in this position.

Quadriplegia in a patient who underwent posterior fossa surgery in the prone position. Case report

Quadriplegia is a well-known complication of posterior fossa surgery performed while the patient is in the sitting position but is rarely associated with the prone position. A case of an 18-year-old man with a cerebellar medulloblastoma is described. There was no evidence of previous cervical disease. The patient suffered quadriplegia after undergoing surgery in the prone position. Postoperative magnetic resonance imaging demonstrated a long hyperintense C2-T1 lesion on T2-weighted sequences. The authors speculate that, during the prolonged period in which the neck was in hyperflexion, overstretching of the cervical spinal cord and compromise of its blood supply might have caused this devastating complication.

Medulloblastomas of the cerebellopontine angle

It is unusual for a medulloblastoma to occur in the cerebellopontine angle (CPA). Four of the total 63 cases of medulloblastoma managed in our department between 1988 to 1998, presented with a mass in the cerebellopontine angle. There were two children amongst these four patients, aged eight and nine years. The other two patients were young adults. Three patients had primary CPA medulloblastoma, while the fourth case had a recurrence in this region, following the excision of the primary vermian tumour. All the four cases were managed by gross total microsurgical excision and craniospinal irradiation. One of the two children, developed subfrontal recurrence after 1 year and 8 months of initial treatment, while the other child developed a large recurrence at primary site, within three months of post-operative irradiation. However, the adult patient developed CPA recurrence and subsequent cervical intramedullary metastasis within two and a half years of diagnosis. These three cases succumbed to their disease, between three months to thirty months of their initial management. However the fourth patient, a 20 years female with desmoplastic variant, was well at two and a half years of follow up.

Medulloblastoma in a child with Rubenstein-Taybi Syndrome: case report and review of the literature

Although medulloblastoma is usually sporadic, there are a number of uncommon predisposing germline mutation syndromes, including: Gorlin's Syndrome, Turcot's Syndrome and Li-Fraumeni Syndrome. Patients with Rubenstein-Taybi Syndrome secondary to mutation/deletion of the CBP gene on chromosome 16 are predisposed to a variety of developmental anomalies as well as cancer. We report a child with Rubenstein-Taybi syndrome who developed a cerebellar medulloblastoma and review the literature on Rubenstein-Taybi Syndrome and pediatric medulloblastoma. As the product of the CBP gene functions in a variety of signaling pathways, we discuss the molecular implications of findings a medulloblastoma in a child with Rubenstein-Taybi Syndrome.

Clinical and molecular stratification of disease risk in medulloblastoma

The accurate assessment of disease risk among children with medulloblastoma remains a major challenge to the field of paediatric neuro-oncology. In the current study we investigated the capacity of molecular abnormalities to increase the accuracy of disease risk stratification above that afforded by clinical staging alone. 41 primary medulloblastoma tumour samples were analysed for ErbB2 receptor expression using immunohistochemistry, and for aberrations of chromosome 17 and amplification of the MYC oncogene using fluorescence in situ hybridisation. The ErbB2 receptor and deletion of 17p were detected in 80% and 49% of tumours, respectively. 17p loss occurred either in isolation (20%), or in association with gain of 17q (29%), compatible with an isochromosome of 17q. Amplification of MYC was detected in only 2 tumours. Significant prognostic factors included, 'metastatic disease' (P = 0.0006), 'sub-total tumour resection' (P = 0.007), 'high ErbB2 receptor expression' (P = 0.003) and 'isolated 17p loss' (P = 0.003). Combined analysis of clinical and molecular factors enabled greater resolution of disease risk than clinical factors alone, identifying a sub-population of patients with particularly favourable disease outcome. These data support the hypothesis that a combination of clinical and molecular factors may afford a more reliable means of assigning disease risk in patients with medulloblastoma, thereby providing a more accurate basis for targeting therapy in children with this disease.

Radiation-induced meningioma with a long latency period: a case report

Multiple meningiomas were diagnosed in a 43-year-old man previously treated with high-dose craniospinal radiotherapy at the age of 7 years for medulloblastoma. We suggest that surveillance MRI after high-dose craniospinal radiotherapy should be extended to several (3-5) decades.

Uncommon presentation of medulloblastoma

INTRODUCTION

Medulloblastoma commonly occurs in children as a midline posterior fossa mass arising from the vermis, which appears as a hyperdense, homogeneously enhancing mass on CT scan and is associated with the clinical profile of posterior fossa syndrome. This unique clinico-radiological pattern is considered 'typical', but then medulloblastomas do not follow the typical clinico-radiological pattern in a significant number of cases.

PATIENTS

Out of the 42 cases of medulloblastoma operated on at SGPGIMS from 1988 to 1998, 29 cases were retrospectively and 13 cases were prospectively studied to detect the atypical clinico-radiological features. The typical radiological feature of a hyperdense homogeneously enhancing mass was seen in only 23 of the 42 patients, while 5 patients had hypodense nonenhancing masses, 13 had cystic changes, and 6 patients had calcifications in their tumours. Three patients presented with tumours in a very unusual location, i.e. the cerebellopontine angle cistern.

RESULTS

During follow-up, which ranged from a minimum period of 1 year to a maximum of 9 years, patients came back with metastases at very unusual sites. There were 5 cases of metastases in the frontal and subfrontal area (developed between 5 months and 5 years following surgery), and 1 patient developed a cervical intramedullary metastasis. Two patients developed abdominal metastases and ascites 2 years after definitive surgery and ventriculo-peritoneal shunting. Each of these 2 patients, however, had received a full course of craniospinal irradiation following surgery. Thus, we had a number of cases with an unusual clinical, radiological and metastatic pattern.

Medullomyoblastoma: case report

This 7-year-old boy presented with a 2-week history of headache, nausea, vomiting, anorexia, lethargy, and unsteadiness of gait. Brain magnetic resonance imaging (MRI) revealed a cystic mass within the vermis of the cerebellum. A suboccipital craniectomy was performed to remove a tumor that contained primitive neuroectodermal cells with florid skeletal muscle differentiation. Immunohistochemical studies and electron microscopy confirmed the presence of both a primitive neuroectodermal component and rhabdomyoblastic differentiation, consistent with the diagnosis of medullomyoblastoma. This exceedingly rare tumor of the cerebellar vermis of children is characterized by two components: primitive neuroectodermal tumor cells and skeletal muscle. Although the histogenesis remains uncertain, advances in immunohistochemistry and electron microscopy suggest the origin of this tumor from a multipotential stem cell precursor.

Thyroid dysfunction as a late effect in childhood medulloblastoma: a comparison of hyperfractionated versus conventionally fractionated craniospinal radiotherapy

PURPOSE

Primary hypothyroidism is a common sequela of craniospinal radiotherapy in the treatment of childhood medulloblastoma. Due to the strong radiobiologic rationale, hyperfractionation can reduce the delayed effects of radiation injury.

METHODS AND MATERIALS

The authors compared the incidence of thyroid dysfunction after conventionally fractionated radiotherapy (Group A, n = 20 patients) vs. hyperfractionated radiotherapy (Group B, n = 12 patients) in a group of pediatric patients with posterior fossa primitive neuroectodermal tumor (PNET).

RESULTS

The mean age at the time of tumor diagnosis was 7.4 years in Group A and 8.4 years in Group B. Thyroid function was evaluated yearly, with ultrasonographic examination every 2 years. The patients were followed after diagnosis for a mean of 10.8 years for Group A and 6.0 years for Group B. Approximately 80% of the Group A (16/20) and 33.3% of the Group B (4/12) patients developed primary hypothyroidism within a similar period after irradiation (4.2 vs. 3.5 years, respectively). Analysis by cumulative incidence function demonstrated a significant difference in the risk of developing thyroid dysfunction between these two groups of patients (p < 0.05). Ultrasonography showed reduced thyroid volume in 7 Group A patients and structural changes in 21 patients (17 Group A, 4 Group B cases); a thyroid benign nodule was detected in 2 Group A patients.

CONCLUSIONS

The current study findings suggest that the use of hyperfractionated craniospinal radiotherapy in the treatment of childhood medulloblastoma is associated with a lower risk of these patients' developing late thyroid dysfunction.

Radiosurgery in the management of pediatric brain tumors

OBJECTIVE

To describe the outcome of pediatric brain tumor patients following stereotactic radiosurgery (SRS), and factors associated with progression-free survival.

METHODS

We reviewed the outcome of 90 children treated with SRS for recurrent (n = 62) or residual (n = 28) brain tumors over a 10-year period. Median follow-up from SRS was 24 months for all patients and 55.5 months for the 34 patients currently alive.

RESULTS

The median progression-free survival (PFS) for all patients was 13 months. Median PFS according to tumor histology was medulloblastoma = 11 months, ependymoma = 8.5 months, glioblastoma and anaplastic astrocytoma = 12 months. Median PFS in patients treated to a single lesion was 15.4 months. No patient undergoing SRS to more than 1 lesion survived disease free beyond 2 years. After adjusting for histology and other clinical factors, SRS for tumor recurrence (RR = 2.49) and the presence of > 1 lesion (RR = 2.3) were associated with a significantly increased rate of progression (p < 0.05). Three-year actuarial local control (LC) was as follows: medulloblastoma = 57%, ependymoma = 29%, anaplastic astrocytoma/glioblastoma = 60%, other histologies = 56%. Nineteen patients with radionecrosis and progressive neurologic symptoms underwent reoperation after an interval of 0.6-62 months following SRS. Pathology revealed necrosis with no evidence of tumor in 9 of these cases.

CONCLUSION

SRS can be given safely to selected children with brain tumors. SRS appears to reduce the proportion of first failures occurring locally and is associated with better outcome when given as a part of initial management. Some patients with unresectable relapsed disease can be salvaged with SRS. SRS to multiple lesions does not appear to be curative. Serious neurologic symptoms requiring reoperation is infrequently caused by radionecrosis alone.

Anaesthetic management of a child with a positive family history of malignant hyperthermia for posterior fossa surgery in the sitting position

A 6-year-old boy with a positive family history of malignant hyperthermia presented for posterior fossa craniectomy and excision of medulloblastoma. A nontriggering anaesthetic was therefore planned using infusions of propofol and remifentanil and a vapour free anaesthetic system delivering an oxygen/air mixture. The surgery was carried out with the child in the sitting position.

Large cell/anaplastic medulloblastomas and medullomyoblastomas: clinicopathological and genetic features

OBJECT

Medulloblastoma is the most common malignant central nervous system neoplasm found in children. A distinct variant designated large cell/anaplastic (LC/A) medulloblastoma is characterized by frequent dissemination of cerebrospinal fluid (CSF) at presentation and a more aggressive clinical course. The authors report on their examination of the clinicopathological and genetic features of seven such cases encountered at their institution.

METHODS

Eighty cases of medulloblastomas were reviewed and seven (8.8%) of these were believed to fit the histological and immunohistochemical criteria for LC/A medulloblastoma. In three cases (43%) either desmoplastic or classic medulloblastoma was the underlying subtype, and in two cases (28%) the LC/A tumor was found within the setting of medullomyoblastoma. Fluorescence in situ hybridization was used in six of the seven cases to characterize the presence of isochromosome 17q, deletion of chromosome 22q (a deletion characteristically found in atypical teratoid/rhabdoid tumors), and c-myc amplification. The patients' clinical histories revealed CSF dissemination in all cases and lymph node metastasis in one case. Isochromosome 17q was found in five (83%) of six cases. Evidence of chromosomal gains indicated aneuploidy in three tumors (50%), and amplification of c-myc was found in three tumors (50%). No 22q deletions were encountered.

CONCLUSIONS

A high percentage of LC/A medulloblastomas arise within a background of typical medulloblastomas or medullomyoblastomas. As is the case in conventional medulloblastomas, the presence of 17q is a common early tumorigenic event; however, in a significant percentage of specimens there is also evidence of aneuploidy and/or amplification of c-myc. These findings indicate that LC/A morphological characteristics reflect a more advanced tumor stage than that found in pure medulloblastomas or in typical medullomyoblastomas.

Feasibility of four consecutive high-dose chemotherapy cycles with stem-cell rescue for patients with newly diagnosed medulloblastoma or supratentorial primitive neuroectodermal tumor after craniospinal radiotherapy: results of a collaborative study

PURPOSE

This study was designed to determine the feasibility and safety of delivering four consecutive cycles of high-dose cyclophosphamide, cisplatin, and vincristine, each followed by stem-cell rescue, every 4 weeks, after completion of risk-adapted craniospinal irradiation to children with newly diagnosed medulloblastoma or supratentorial primitive neuroectodermal tumor (PNET).

PATIENTS AND METHODS

Fifty-three patients, 19 with high-risk disease and 34 with average-risk disease, were enrolled onto this study. After surgical resection, high-risk patients were treated with topotecan in a 6-week phase II window followed by craniospinal radiation therapy and four cycles of high-dose cyclophosphamide (4,000 mg/m2 per cycle), with cisplatin (75 mg/m2 per cycle), and vincristine (two 1.5-mg/m2 doses per cycle). Support with peripheral blood stem cells or bone marrow and with granulocyte colony-stimulating factor was administered after each cycle of high-dose chemotherapy. Treatment of average-risk patients consisted of surgical resection and craniospinal irradiation, followed by the same chemotherapy given to patients with high-risk disease. The expected duration of the chemotherapy was 16 weeks, with a cumulative cyclophosphamide dose of 16,000 mg/m2 and a planned dose-intensity of 1,000 mg/m2/wk.

RESULTS

Fifty of the 53 patients commenced high-dose chemotherapy, and 49 patients completed all four cycles. The median length of chemotherapy cycles one through four was 28, 27, 29, and 28 days, respectively. Engraftment occurred at a median of 14 to 15 days after infusion of stem cells or autologous bone marrow. The intended dose-intensity of cyclophosphamide was 1,000 mg/m2/wk; the median delivered dose-intensity was 1,014, 1,023, 974, and 991 mg/m2/wk for cycles 1 through 4, respectively; associated median relative dose-intensity was 101%, 102%, 97%, and 99%. No deaths were attributable to the toxic effects of high-dose chemotherapy. Early outcome analysis indicates a 2-year progression-free survival of 93.6% +/- 4.7% for the average-risk patients. For the high-risk patients, the 2-year progression-free survival is 73.7% +/- 10.5% from the start of therapy and 84.2% +/- 8.6% from the start of radiation therapy.

CONCLUSION

Administering four consecutive cycles of high-dose chemotherapy with stem-cell support after surgical resection and craniospinal irradiation is feasible in newly diagnosed patients with medulloblastoma/supratentorial PNET with aggressive supportive care. The early outcome results of this approach are very encouraging.

Shunt-related abdominal metastases in an infant with medulloblastoma: long-term remission by systemic chemotherapy and surgery

This is the first reported case of long remission of abdominal metastases spread through a ventriculo-peritoneal shunt in an infant diagnosed, four years ago, at age 1 year and 10 months, to have cerebral medulloblastoma. Two years later, while in second complete remission of his cerebral tumor, he showed abdominal metastases, successfully treated by platinum based chemotherapy and surgery. One year later, a second abdominal relapse and hepatic metastases were treated by doxorubicin administration and surgery. Since then the child remained in continuous complete remission. This unusual favorable outcome can be explained by an extreme responsiveness of the tumor, unprotected by the blood brain barrier, to systemic chemotherapy, particularly to doxorubicin administration. The need for careful surveillance of patients with ventriculo-peritoneal shunts is emphasized. Searching for new tools, such as entrapment of doxorubicin in liposomes, able to overcome the blood-brain barrier and to expose brain tumors to effective drugs, probably represents the best choice for future treatment strategies of CNS tumors.

Microcephalus, medulloblastoma and excessive toxicity from chemotherapy: an unusual presentation of Fanconi anaemia

Fanconi anaemia is a genetically and phenotypically heterogeneous disorder with different forms of clinical presentation. In this case the patient had suffered from microcephalus and delayed motor development from birth, but extensive investigation did not disclose any aetiology. At 3.5 y she developed a cerebellar medulloblastoma which was treated with surgery and chemotherapy. Following chemotherapy with alkylating agents she suffered from severe bone marrow aplasia which caused life-threatening infections, feeding problems and impaired kidney function. Fanconi anaemia was suspected, but it took 2 mo before the chromosome fragility test came out positive. From the moment diagnosis of Fanconi anaemia was made, no further active treatment was given. The patient's condition improved for some time, but she relapsed and died exactly 1 y after the first diagnosis of brain tumour.

CONCLUSION

Fanconi anaemia must always be suspected in patients who experience excessive toxicity from chemotherapy regardless of the type of malignancy and congenital malformations.

Bilateral crossed cerebello-cerebral diaschisis and mutism after surgery for cerebellar medulloblastoma

A 7-year-old boy developed mutism after surgery for cerebellar medulloblastoma. Postoperative magnetic resonance imaging (MRI) showed atrophy of the cerebellar vermis and both cerebellar hemispheres, predominantly on the right side. Single photon emission computed tomography (SPECT) with technetium-99m-ethyl cysteinate dimer (Tc-99m ECD) revealed decreased cerebral blood flow (CBF) in the bilateral thalami, bilateral medial frontal lobes, and left temporal lobe in addition to the cerebellar vermis and both cerebellar hemispheres when mutism was manifest, indicating the existence of bilateral crossed cerebello-cerebral diaschisis (BCCCD). Circulatory disturbance in both cerebellar hemispheres secondary to tumor resection probably caused BCCCD in both cerebral hemispheres, predominantly in the left, via the dentatothalamocortical pathway (DTCP). With recovery of his mutism, CBF increased in the right thalamus, bilateral medial frontal lobes and left temporal lobe. Thus BCCCD was improved, with only a slight decrease in CBF still persisting in the left thalamus. The mechanism of mutism may have involved damage to the cerebellar vermis (the site of incision at operation), the left dentate nucleus (heavily infiltrated by the tumor) and the right dentate nucleus of the cerebellum (affected by circulatory disturbance secondary to acute postoperative edema). The SPECT findings suggested that mutism was associated with BCCCD-induced cerebral circulatory and metabolic hypofunction in the supplementary motor area mediated via the DTCP.

Cerebellar mutism after posterior fossa surgery

A large midline posterior fossa medulluloblastoma and a cerebellar arteriovenous malformation with associated clot were moved with postoperative mutism. Mutism was immediate and resolved into an ataxic dysarthria with residual mild dysarthria at 3 months. The literature is reviewed, and the clinicopathological and neurophysiological data of cerebellar function in speech are discussed. Acute injury to the midportion of the cerebellum with or without dentate nuclear involvement can cause a spectrum of speech disturbances. The more widespread the injury to the midportion of the cerebellum with dentate nuclei involvement the greater the risk of developing postoperative mutism.

Mutism after surgical removal of a cerebellar tumor: two case reports

The authors report two pediatric cases of transient mutism that occurred after surgical removal of a medulloblastoma and a pilocytic astrocytoma of the vermis and discuss the pathophysiology of this syndrome. Transient mutism has been described for the first time quite recently, even in cases where these tumors were also surgically removed before. Perhaps improvement in imaging and in surgical techniques made neurosurgeons more daring and some interventions that were judged impossible are routinely performed today. If this is the case, postoperative transient cerebellar mutism might be considered the price that must be paid in order to cure more patients with cerebellar tumors.

Advances in biology and treatment of childhood brain tumors

Childhood brain tumors are collectively the most common solid neoplasm and the leading cause of cancer-related death in children. They are a diverse group of diseases and outcome is extremely variable. Current treatment is dependent on histology, location, and in some instances, patient age. Advances in treatment have led to improved survival for some patients, but for many the outcome remains dismal despite aggressive treatment. A growing body of work is aimed at improving the outcome for children with brain tumors not only through clinical trials, but also by focusing on the biologic underpinning of these diseases that have been poorly understood.

Transcerebellomedullary fissure approach with special reference to methods of dissecting the fissure

OBJECT

The purpose of the present study was to refine the transcerebellomedullary fissure approach to the fourth ventricle and to clarify the optimal method of dissecting the fissure to obtain an appropriate operative view without splitting the inferior vermis.

METHODS

The authors studied the microsurgical anatomy by using formalin-fixed specimens to determine the most appropriate method of dissecting the cerebellomedullary fissure. While dissecting the spaces around the tonsils and making incisions in the ventricle roof, the procedures used to expose each ventricle wall were studied. Based on their findings, the authors adopted the best approach for use in 19 cases of fourth ventricle tumor. The fissure was further separated into two slit spaces on each side: namely the uvulotonsillar and medullotonsillar spaces. The floor of the fissure was composed of the tela choroidea, inferior medullary velum, and lateral recess, which form the ventricle roof. In this approach, the authors first dissected the spaces around the tonsils and then incised the taenia with or without the posterior margin of the lateral recess. These precise dissections allowed for easy retraction of the tonsil(s) and uvula and provided a sufficient view of the ventricle wall such that the deep aqueductal region and the lateral region around the lateral recess could be seen without splitting the vermis. The dissecting method could be divided into three different types, including extensive (aqueduct), lateral wall, and lateral recess, depending on the location of the ventricle wall and the extent of surgical exposure required.

CONCLUSIONS

When the fissure is appropriately and completely opened, the approach provides a sufficient operative view without splitting the vermis. Two key principles of this opening method are sufficient dissection of the spaces around the tonsil(s) and an incision of the appropriate portions of the ventricle roof. The taenia(e) with or without the posterior margin of the lateral recess(es) should be incised.

[Adult medulloblastoma. Review of 22 patients]

BACKGROUND AND PURPOSE

Medulloblastoma is a malignant neuro-ectodermal tumor classically considered as a pediatric tumor. Adult medulloblastoma is rare. This low incidence results in a lack of data concerning the management of treatment. We report our experience and propose a review of the literature to clarify the main therapeutic options that are nowadays suggested.

METHODS

We reviewed 22 adult patients treated for cerebellar medulloblastoma between 1979 and 1999. Actuarial relapse-free and overall survival were determined by the Kaplan-Meier method. Prognosis factors were studied by Log- Rank test.

RESULTS

The five years relapse free and overall survival rates were respectively 63.1% and 81.3%. These rates are superior to those reported in the literature. None of the studied factors (age, gender, histological subtype, total or partial surgery, presence of a CSF derivation device, radiotherapy, chemotherapy) were significantly associated to remission or survival. However our statistical results should be interpreted with caution in this small population.

CONCLUSION

Adult medulloblastoma prognosis seems to improve since chemotherapy has been introduced in the therapeutic protocols. Prospective and multicentric studies should determine the exact pattern of treatment.

Adult medulloblastoma: multiagent chemotherapy

In this study, the records of 17 adult patients with medulloblastoma treated with craniospinal radiation and 1 of 2 multiagent chemotherapy protocols were reviewed for progression-free survival, overall survival, and toxicity, and the patients were compared with each other and with similarly treated children and adults. Records of patients treated at 3 institutions were reviewed. Seventeen medulloblastoma patients (11 female, 6 male) with a median age of 23 years (range, 18-47 years) were treated with surgery, craniospinal radiation (CSRT) plus local boost, and 1 of 2 adjuvant chemotherapy regimens. All tumors were infratentorial (10 in 4th ventricle and 7 in left or right hemisphere). Ten patients presented with hydrocephalus, and 7 of them were shunted. Eight patients had gross total resection, 7 had subtotal resection (>50% removed), and 2 had partial resection (<50% removed). Postoperatively, 3 patients had positive cytology and 3 had positive spinal MRI. Five patients were classified as good risk and 12 were classified as poor risk (Chang staging system). Ten patients were treated with the "Packer protocol," consisting of CSRT plus weekly vincristine followed by 8 cycles of cisplatin, lomustine, and vincristine. Seven patients were treated with the Pediatric Oncology Group (POG) protocol, consisting of alternating courses of cisplatin/etoposide and cyclophosphamide/vincristine, followed by CSRT. Eight of 17 patients relapsed, with all 8 relapsing at the primary site. Other relapse sites included the leptomeninges (5), bone (1), and brain (1). The estimated median relapse-free survival (Kaplan-Meier) for all patients was 48 months (95% confidence interval, >26 months to infinity). Median relapse-free survival for patients on the Packer protocol was 26 months, and for those on the POG regimen was 48 months (P = 0.410). Five of 10 on the Packer protocol were relapse-free, while 4 of 7 were relapse-free on the POG regimen. Two patients relapsed during chemotherapy and 6 relapsed after completing all therapy at 18, 18, 26, 30, 40, and 48 months. The estimated median survival of all patients was 56 months (95% confidence interval, 27 to infinity) with 11 patients alive; for the Packer protocol, median survival was 36 months, and for the POG protocol, it was 57 months (P = 0.058). The hazard ratio was 0 (95% confidence interval, 0 to infinity). Toxicity during the Packer protocol was moderately severe, with only 1 of 10 patients able to complete all therapy. Two patients had severe abdominal pain during CSRT + vincristine, and 5 had peripheral neuropathy during vincristine therapy. Hearing loss (>20 dB) occurred in 7, neutropenia (<500 microl) in 6, thrombocytopenia (<50,000 microl) in 6, nephrotoxicity (>25% decrease by creatinine clearance) in 2, and decreased pulmonary function (diffusing capacity for carbon monoxide decrease >40%) in 1. On the POG protocol, only 1 patient had persistent nausea and vomiting, 2 had peripheral neuropathy, and 3 had hearing deficit (>20 dB) or tinnitus. The POG and Packer protocols did not have a statistically significant difference in relapse-free or overall survival because of the small sample size. The POG protocol seemed to have less nonhematologic toxicity. Adults on the Packer protocol appeared to have shorter median survival and greater toxicity than did children. To know whether adding adjuvant chemotherapy to craniospinal radiation in adult therapy increases relapse-free and overall survival, we must await the results of a larger randomized controlled clinical trial.

Medulloblastoma in late adults. Case report and critical review of the literature

BACKGROUND

Medulloblastoma in late adults (older than 65 years) is an exceptional occurrence; in fact only 8 cases are reported with complete clinical notes in the literature.

METHODS

The authors describe a case of medulloblastoma occurring in a 68-year-old man and analyzed cases reported in the literature.

RESULTS

The overall average age of the patients was 72.8 years (range 67-88 years), and the male prevalence of this tumour (70% of cases) seems to be unrelated to age. There is a lateral predominance in late adults (77.7% of cases). Seven patients underwent operation and subsequently these patients underwent a course of radiation therapy. Only two patient was treated with postoperative chemotherapy. Median survival for seven patients treated was 43.2 months (range 23-96 months).

CONCLUSIONS

It is interesting to note that: 1) histological analysis revealed a classic type medulloblastoma (88.8% of cases) similar to the children: 2) site of the tumor is lateral similar to the adults (77.7% of cases).

Herpes simplex encephalitis occurring after chemotherapy, surgery, and stereotactic radiotherapy for medulloblastoma

Reactivation of latent herpes simplex virus (HSV) in the trigeminal ganglion most commonly gives rise to recurrent herpes labialis and rarely to herpes simplex encephalitis. The mechanisms underlying reactivation of latent trigeminal HSV are complex. Here we report the case history of a 25-year-old woman who developed a fatal, bilateral necrotizing destructive temporal lobe lesion following surgical removal of a cerebellar medulloblastoma and combined radiotherapy and chemotherapy for recurrent tumor. Neuropathologic examination of the brain revealed minimal inflammatory changes, but immunohistochemistry was positive for HSV protein, and HSV deoxyribonucleic acid (DNA) was recovered from formalin-fixed paraffin-embedded brain tissue. The temporal proximity of the surgery, chemotherapy, and radiotherapy to the onset of disease suggests that these factors may have acted as triggers that precipitated conversion of latent HSV to overt HSV.