Gliomatosis cerebri: Results with radiation therapy

AJAP1 expression modulates glioma cell motility and correlates with tumor growth and survival

Glioblastoma multiforme (GBM) is one of the most common primary malignant brain tumors. Unraveling the molecular and genetic complexity that determines GBM's pronounced migratory property could provide new options for therapeutic targeting that may significantly complement current surgical and chemoradiation therapy and alter the current poor outcome. In this study, we establish stable AJAP1 overexpressing glioma cells in order to examine in vivo tumor growth. We examine AJAP1 localization by confocal microscopy and AJAP1's functional effect on migration and invasion across surfaces coated with laminin. Finally, analysis of AJAP1 expression in murine xenografts and GBM primary tumors revealed its association with tumor growth and survival. Stable overexpression of AJAP1 promotes adherence, decreases invasion of glioma cells through an extracellular-like matrix, and slows migration in the presence of laminin. These observations are reversed by gene knockdown using multiple siRNAs. Additionally, overexpression of AJAP1 decreases colony formation in glioma cells, and leads to smaller tumor growth with increased survival in glioma xenograft mice. Loss of AJAP1 protein expression predicts worse survival in GBM patients. AJAP1 overexpression decreases cell motility in the presence of laminin and decreases tumor growth in xenografts. Its loss of expression predicts worse survival in patients. This study extends our prior observations and implicates AJAP1 as a potential prognostic marker and a viable target for therapeutic intervention in GBM.

Gliomatosis Cerebri: Current Understanding and Controversies

Gliomatosis cerebri (GC) is a rare, extensively infiltrating glioma involving multiple contiguous lobes of the brain. This lethal disease affects all age groups, and the majority of patients have a poor outcome despite aggressive treatment. Despite its initial recognition in 1938, GC remains a controversial entity with little consensus in its definition, histology, or treatment. The majority of GC tumors are astrocytic, although mixed phenotypes have been identified. Treatment of GC is challenging as surgery is generally not an option due to the extensive areas of brain involved, the benefit of radiation therapy is unclear, and no chemotherapy has proven efficacy. Due to the rarity of the disease and its heterogeneity, both at histopathological and molecular levels, it is difficult to conduct clinical trials tailored for this diagnosis. This review summarizes our current knowledge, examines clinical studies focusing on the treatment of GC, highlights ongoing challenges, and discusses the recent molecular insights into adult and pediatric GC. We conclude that, although no longer recognized as a distinct pathological entity, GC represents a unique disease phenotype. Given the histologic and molecular overlap with other diffuse gliomas, the research emphasis should be on investigating its unique invasive biology.

Gliomatosis cerebri: a review

OPINION STATEMENT

Gliomatosis cerebri (GC) is an intriguing disease for several reasons. First, it is difficult to draw the border between GC and diffuse gliomas. In this regard, GC could represent the most invasive form of diffuse gliomas. Second, both in terms of histologic grading and clinical course, GC is a heterogeneous disease, ranging from rapidly evolving to slowly and somewhat indolent forms. Because of the extensive spread of the disease, surgery-outside a biopsy for diagnosis-is rarely indicated in gliomatosis cerebri. Therapeutic options include radiotherapy, generally involving the whole brain, and chemotherapy with temozolomide or nitrosoureas. Because of the rarity of the disease, no trial comparing these two modalities has been undertaken so far. Decision is, therefore, based on small retrospective noncomparative studies and expert opinions. On one hand, there is a rationale to postpone the whole brain radiotherapy because of late neurotoxicity, but on the other hand, there is also the risk that an aggressive disease evolves to intracranial hypertension making the radiotherapy hazardous or even impossible. As a consequence, the patient would lose the opportunity to receive a potentially effective treatment. In this decision, the evaluation of histologic data together with clinical and radiologic features, performance status, and molecular profile may be of help. Because radiotherapy usually involves large volumes of the brain, chemotherapy is generally preferred up front in patients with a slowly evolving disease. Conversely, in patients with rapidly (ie, over few weeks) evolving disease with neurologic deficits or when histologic features of glioblastoma are evident, whole brain radiotherapy (45 Gy with 1.8 Gy fractions), alone or associated with concomitant temozolomide, is often preferred. The value of advanced of magnetic resonance imaging and positron emission tomography techniques to predict outcome and monitoring the treatment still remains to be defined.

Gliomatosis cerebri: clinical characteristics, management, and outcomes

Gliomatosis cerebri is a rare diffusely infiltrating primary neoplastic glial process of the brain. Our objective is to review clinical presentation, management, and outcome in a large single institution series of gliomatosis cerebri patients. 54 consecutive gliomatosis cerebri cases presenting to Mayo Clinic Rochester between 1991 and 2008 were retrospectively reviewed. Inclusion criteria included involvement of at least three cerebral lobes, lack of a single discrete mass and pathological confirmation of diffuse glioma. Median overall survival (OS) was 18.5 months. Age, gender, presenting symptoms, and contrast enhancement did not correlate significantly with survival, though there was a trend toward decreased overall survival in patients above the median age of 46 years. Karnofsky performance score <70 was associated with poor OS (median 9.5 vs. 20.5 months, p = 0.02). Higher histologic grade was associated with poor progression-free survival (PFS; median for WHO grades II, III, and IV: 21.5, 6.5, and 4 months; p = 0.03) and OS (median 34, 15.5, and 8.5 months; p < 0.05). Radiation therapy was strongly associated with better prognosis (PFS 16.5 vs. 4.5 months, p < 0.01; OS 27.5 vs. 6.5, p < 0.01), but chemotherapy was not. Gliomatosis cerebri patients have a poor prognosis. Lower KPS upon presentation and higher histologic grade predict decreased survival. Surgery's role is limited beyond biopsy for diagnostic purposes. Radiotherapy appears beneficial, although selection bias could be present in this retrospective study. Chemotherapy's value is not as clear but this must be interpreted with caution given variable treatment regimens in this series.

Marked response of gliomatosis cerebri to temozolomide and whole brain radiotherapy

Gliomatosis cerebri (GC) represents an unfortunate, rare variant of glioma with a very poor prognosis. Given this lesion's rarity, little information exists on appropriate treatment options. The diffuse, infiltrative nature of GC precludes any surgical resection and limits therapy. Because of the improved survival seen with the use of temozolomide (TMZ) in malignant glioma, a rigorous systematic review of the published literature was performed to ascertain the benefit of TMZ in GC. We identified all GC cases in the literature where there was enough information to ascertain a clear response to a specific chemoradiotherapeutic treatment. In addition to our experience with a recent case, we have identified 61 patients with GC in the published literature who demonstrated a positive radiographic or clinic response after treatment. Statistical analysis of survival was performed by Kaplan-Meier analysis. A positive radiographic and clinical response was seen in patients ranging in age from 4 to 84 years. Overall median survival in patients diagnosed with GC who demonstrated a response after treatment was 25 months, with 1- and 2-year survival rates of 89% and 55%, respectively. The most common treatment regimens for responders included TMZ alone (26.2%), external whole-brain radiotherapy (WBRT) (26.2%), and concomitant TMZ and WBRT (20%). Our patient was treated with concomitant TMZ (150 mg/m(2)/day over 5 days) and WBRT (50 Gy) and has remained with a complete radiographic response after 36 months. In conclusion, patients with GC confirmed by surgical biopsy should be aggressively treated with concomitant TMZ and WBRT, as marked responses have been seen, and this appears to offer overall survival benefit.

Presentation patterns and outcome of gliomatosis cerebri

A total of 25 patients with gliomatosis cerebri (19 males and 6 females; median age 51 years, range 10-73 years) were diagnosed and treated at the Sheba Medical Center between 1995 and 2009. Of these, 3 patients were 10 years old at the time of diagnosis. Seizures were the initial clinical presentation in 19 patients, focal signs in 16 patients, headaches in 7 patients, cognitive disorder in 4 patients and rapidly progressive hemiparesis in 1 patient. Magnetic resonance imaging (MRI) was performed in the patients and demonstrated a diffuse infiltrative process with a hyperintensity signal on T2-weighted images and a minimal mass effect. Some level of enhancement on MRI was observed in 6 patients. The infiltrative process involved at least two lobes in each patient. Biopsy was performed for diagnosis in the majority of patients. In 1 patient with a markedly rapid deterioration, the diagnosis was established at autopsy. The pathology was compatible with gliomatosis with a diffuse infiltrative low-grade astrocytoma in 21 patients and anaplastic astrocytoma in 5 patients. The patients were treated with whole-brain radiation therapy and 7 patients were treated with combined whole-brain radiation therapy and chemotherapy. Treatment appeared to stabilize 6 patients or improve the clinical condition in 7 patients. Due to the small number of patients in the present study, however, further studies are required to determine the effect of treatment on the natural history of the disease.

Genetic aberrations in gliomatosis cerebri

OBJECTIVE

Identifying the genetic alterations in gliomatosis cerebri (GC) may yield clinically useful prognostic markers and provide clues as to whether GC represents a distinct pathological entity or is an extreme form of diffusely infiltrative glioma.

METHODS

Clinical histories, treatment histories, magnetic resonance imaging, and pathological analysis of patients with GC treated at either the University of California San Francisco or the Mayo Clinic were reviewed. Degenerate oligonucleotide-primed polymerase chain reaction was performed on biopsy samples of GC. Comparative genomic hybridization was used to determine relative deoxyribonucleic acid copy number. We evaluated relationships of clinical and radiological treatment and comparative genomic hybridization data to survival after diagnosis with Cox regression analysis.

RESULTS

Radiographic analysis and biopsy specimens were available for study in 29 patients (17 men, 12 women). Comparative genomic hybridization was successfully performed in 22 patients. Contrast enhancement was the most significant predictor of poor survival (P = 0.0026). Loss of chromosomes 13q and 10q and gains of 7q were also independent significant predictors of poor survival (P = 0.0032, 0.0335, and 0.0487, respectively). Patients treated with temozolomide or with radiation therapy had improved survival, but this effect did not reach statistical significance (P = 0.180 and 0.124, respectively).

CONCLUSION

Chromosomal aberrations associated with aggressive astrocytomas are predictors of poor outcome in patients with GC. This suggests that GC may be an architectural variant of diffuse astrocytomas. The presence of these aberrations and the presence of any contrast enhancement on magnetic resonance imaging scans are possible stratifiers for patients with GC. Stratification of GC into higher- and lower-grade forms may be useful in tailoring treatments to patients with this disease.

Gliomatosis cerebri: 20 years of experience at the Children's Hospital of Philadelphia

BACKGROUND

Gliomatosis cerebri (GC) is a rare and typically fatal glial neoplasm of the central nervous system. In this report, the authors describe the largest cohort of children to date with GC and explore relations between potential prognostic factors, treatment, and survival.

METHODS

Imaging, pathologic, and outcome data were reviewed from 13 patients who were diagnosed with GC and were treated at the Children's Hospital of Philadelphia (CHOP) between 1982 and 2005. All patients had GC confirmed by biopsy. Twelve patients received cranial irradiation, and 8 of those patients received adjuvant chemotherapy. A single patient age 1 year received chemotherapy alone. A review of the literature identified 51 pediatric patients with GC.

RESULTS

The progression-free survival rate in this study was 13% (range, 1.5-43 months), and the overall survival (OS) rate was 64% (range, 6.5-67 months) at 2 years. OS was significantly shorter for patients who presented in the first decade of life (P = .04). The time to progression was prolonged significantly for patients who had no evidence of tumor enhancement on imaging studies (P = .03). When survival data from patients reported in the literature were combined with the CHOP cohort, treatment prolonged OS significantly (P = .003).

CONCLUSIONS

The outcome of pediatric patients with GC was extremely poor; however, the current results indicated that treatment may prolong OS. Age < 10 years and contrast enhancement on magnetic resonance imaging studies at diagnosis may be risk factors for shorter survival in pediatric patients with GC.

Gliomatosis cerebri: quantitative proof of vessel recruitment by cooptation instead of angiogenesis

Object. Gliomas are the most common primary brain tumors, many of which (especially astrocytic and oligodendroglial neoplasms) are characterized by diffuse infiltrative growth in the preexisting brain tissue. Gliomatosis cerebri is a rare glial tumor and represents an extreme example of such diffuse infiltrative growth. This growth pattern not only hampers curative treatment but also allows for vessel cooptation rather than tumor angiogenesis as a way of vessel recruitment by the tumor tissue. The goal of this study was to establish the extent to which tumor angiogenesis occurs in gliomatosis cerebri.

Methods. Computerized image analysis was performed to assess quantitatively two microvascular parameters (vessel density and diameter) in different areas of a brain harboring a gliomatosis cerebri. These regions were the cerebral white and gray matter in which there was a diffuse infiltrative tumor, cerebral white and gray matter in which there was a more compact growth pattern of tumor cells, and normal cerebral white and gray matter. In addition, the authors performed immunohistochemical stainings for blood—brain barrier (BBB) characteristics (Glut-1 and PgP) on samples obtained in these different areas.

The results of the quantitative analysis strongly indicated that in gliomatosis cerebri tumor, angiogenesis was completely absent, a finding that is corroborated by the fact that the microvasculature in gliomatosis cerebri persists in exhibiting immunohistochemical characteristics of the BBB.

Conclusions. The results of this study may help resolve the difficulties in radiological detection and delineation of the diffuse infiltrative part of glial brain tumors and put the expectations for antiangiogenic treatment of such tumors into perspective.

Gliomatosis Cerebri: A Review of 296 Cases from the ANOCEF Database and the Literature

Gliomatosis cerebri (GC) is a rare disease, defined as a diffuse neoplastic glial cell infiltration of the brain. Diagnosis and management of GC are difficult. This study analyzed 296 individual cases (90 patients followed through the ANOCEF network, and 206 cases from the literature), aged 1 month to 85 years (median 42), sex ratio=1.31. Median survival was 14.5 months. It was higher for patients younger than 42 years (17 months vs. 13 months), with performance status>or=80 (27 months vs. 9 months), low grade gliomatosis (grade 2=20 months, grade 3=11.5 months, grade 4=8.5 months), oligodendroglial subtype (36 months compared to 14 months for mixed GC and 11 months for astrocytic GC). Male population was younger (median 39 years vs. 45), had a higher incidence of oligodendroglial GC (22% vs. 13%), which may explain their better prognosis (median survival 17 months vs. 11.5 months) than female population. Despite a high rate of stabilization, the impact on survival of whole brain radiotherapy, which carries the risk of severe toxicity, is still unclear. Up-front chemotherapy benefit to some patients and may be preferred to whole brain radiotherapy. However, the many bias of such retrospective heterogeneous data claim for multicentric clinical trials in this rare disease.

Synchronous Multicentric Pleomorphic Xanthoastrocytoma: Case Report

OBJECTIVE AND IMPORTANCE:

Pleomorphic xanthoastrocytoma (PXA) is a rare, low-grade astrocytoma of adolescence. Relatively favorable outcomes have been achieved with complete surgical resection. However, few data exist regarding the treatment of recurrent, deep-seated, or multicentric lesions. We report the first case to our knowledge of synchronous multicentric PXA and discuss the related therapeutic challenges.

CLINICAL PRESENTATION:

A 13-year-old Hispanic girl presented with a 1-year history of progressive headaches, polyuria, and generalized fatigue. Findings from the neurological examination were notable only for the presence of papilledema. Results of laboratory studies revealed diabetes insipidus and hypothyroidism. The magnetic resonance imaging study revealed numerous nodular, homogeneously enhancing lesions, approximately 1 cm in size, scattered throughout both cerebral hemispheres.

INTERVENTION:

A right frontal craniotomy was performed for excisional biopsy of a superficial lesion beneath the coronal suture. Results of the histological examination were consistent with a diagnosis of PXA. The patient was treated with whole-brain radiation of 3600 cGy, with additional intensity-modulated boosts to the enhancing lesions of 1440 cGy. Three years after treatment, the patient remains neurologically nonfocal and shows no evidence of disease progression. Surgical intervention will be considered if accessible lesions progress in size on later imaging studies.

CONCLUSION:

Synchronous multicentric PXA presents unique challenges in that gross total resection would impose significant surgical morbidity; histological homogeneity among the lesions cannot be confirmed; and the well-described potential for anaplastic transformation may be increased with multiple lesions. The optimal treatment for patients with this rare and challenging diagnosis awaits further study.

La gliomatose cérébrale

INTRODUCTION

Gliomatosis cerebri (GC) is defined as a diffuse neoplastic glial cell infiltration of the brain involving more than two cerebral lobes and, occasionally, the infratentorial structures or the spinal cord. The tumor may appear de novo (primary GC) or result from the spreading of a focal glioma (secondary GC). Diagnosis and management of GC are difficult. Because of the diffuse nature of gliomatosis cerebri (GC), surgery is not suitable and large field radiotherapy carries the risk of severe toxicity.

STATE OF ART

The analysis of current literature shows that the male population (58 percent) is younger, has a higher incidence of oligodendroglial GC and better prognosis than the female population. Survival (median=14.5 months) is also better for young patients, with high performance status, low-grade gliomatosis, and oligodendroglial subtype. Initial chemotherapy results in nearly 30 percent clinical or radiological improvement. In this setting, temozolomide is well tolerated and appears to be a valuable alternative to procarbazine-CCNU-vincristine, especially for slow-growing, low-grade GC.

PERSPECTIVE

Genotyping could be helpful to predict the response to chemotherapy in GC patients.

Gliomatosis cerebri: a review of 22 cases

OBJECTIVE

Gliomatosis cerebri is an enigmatic diffuse brain neoplasm whose prognosis is grim. We reviewed data for patients with gliomatosis who were treated at the University of California, San Francisco, during a 10-year period. Our focus was on presentation, radiological and pathological features, and outcomes.

METHODS

We reviewed hospital and clinic records and magnetic resonance imaging scans for 22 patients with gliomatosis. The diagnosis was based on magnetic resonance imaging findings and tissue confirmation for all patients. Seven patients also underwent magnetic resonance spectroscopy. Eleven patients were male (50%), and the median age at presentation was 49 years (range, 7-79 yr).

RESULTS

Kaplan-Meier analysis demonstrated median lengths of survival as follows: no treatment, 1 month (n = 4); radiotherapy alone, 28 months (95% confidence interval, 5-51 mo; n = 13); radiotherapy followed by chemotherapy, two patients, alive at 28 and 104 months; radiotherapy and chemotherapy simultaneously, three patients, one alive at 18 months and the others dead at 7 and 9 months. There was no significant difference between radiotherapy alone and radiotherapy combined with chemotherapy (P = 0.69). Karnofsky Performance Scale scores of >/=70 and grade were both significantly related to length of survival in univariate analyses (P < 0.05); these correlations were confirmed in the multivariate analysis, although the small numbers of patients and deaths precluded reliable interpretation.

CONCLUSION

Although the small number of patients in our study and its retrospective nature preclude definitive conclusions regarding the utility of treatment, our findings suggest that biopsies are useful not only for diagnosis but also for prediction of the length of survival.

Gliomatosis cerebri: improved outcome with radiotherapy

PURPOSE

Gliomatosis cerebri is a rare, diffuse involvement of the central nervous system by a malignant glioma that permeates the brain extensively without destroying the neural architecture and involves more than two lobes. In this study, we sought to assess the role of radiotherapy (RT) and identify prognostic factors in gliomatosis cerebri.

METHODS AND MATERIALS

Thirty patients who received RT at a single institution and had radiographic follow-up were retrospectively reviewed with respect to outcome, radiation parameters, extent of surgery, and chemotherapy. All cases were analyzed histologically and documented. All pathology slides and radiology images were reviewed.

RESULTS

The median age at diagnosis was 38.6 years (range 16-68). The median follow-up was 12.8 months (range 3-110). The mean radiation dose was 54.9 Gy, given in a mean of 28 fractions. Radiographic improvement or disease stabilization was achieved in 87% of patients. Clinical improvement was observed in 70%. The median time to progression was 10 months, and it was significantly longer for patients <40 years old (p = 0.0007) and for patients having a tumor histologic subtype other than glioblastoma (p = 0.01). The median overall survival was 18 months and was also longer for patients <40 years (p = 0.0001) and for patients having nonglioblastoma histologic features (p = 0.007). Extensive surgery, administration of chemotherapy, or increased RT volume improved neither overall survival nor the time to disease progression.

CONCLUSION

RT is effective against gliomatosis cerebri. Patients who are young and have a nonglioblastoma tumor histologic subtype perform more favorably. In this analysis, no role for chemotherapy, extensive surgery, or whole-brain RT was found.

Posterior fossa decompression for life-threatening tonsillar herniation in patients with gliomatosis cerebri: report of three cases

OBJECTIVE AND IMPORTANCE

Gliomatosis cerebri (GC) is a rare type of primary brain tumor that diffusely infiltrates more than two lobes of the brain while the normal cerebral architecture is maintained. To the best of our knowledge, the association between an acquired tonsillar herniation and GC has never been reported. In this article, we describe three patients with progressive gliomatosis of the cerebellar hemispheres who subsequently showed signs and symptoms secondary to tonsillar herniation. Early recognition of this potentially life-threatening complication allowed us to recommend prompt surgical intervention.

CLINICAL PRESENTATION

One patient with primary, or Type I, GC presented with suboccipital headaches, and two patients with secondary, or Type II, GC presented with the signs and symptoms of progressive myelopathy. Serial imaging studies demonstrated progressive involvement of the cerebellum, descent of the cerebellar tonsils through the foramen magnum, and cervicomedullary spinal cord compression.

INTERVENTION

Once the tonsillar herniation was recognized, all three patients underwent posterior fossa decompression, a cervical laminectomy to the lowest level of the tonsillar herniation, and duraplasty. All three patients experienced immediate improvement in their conditions.

CONCLUSION

Early recognition of tonsillar herniation, a possibly overlooked cause of death in patients with GC, allows for early surgical intervention as a potentially lifesaving procedure and significant improvement in the patient's condition.

Gliomatosis cerebri: treatment results with radiotherapy alone

BACKGROUND

Gliomatosis cerebri (GC) is a rare primary brain tumor characterized by proliferation of neoplastic glial cells that typically involve multiple brain areas, with preservation of brain structures and sparing of neurons. The optimal therapeutic strategy is not well established. The impact of radiotherapy on survival in patients with GC remains undefined.

METHODS

Between 1980 and 2001, 12 patients with GC were identified, representing less than 1% of all patients with primary brain neoplasms treated at the Cleveland Clinic.

RESULTS

All 12 patients had brain biopsies between March 1986 and July 2001 (seven males, five females, with a median age of 53 years [range, 13-85 years]). Median Karnofsky performance status at the time of presentation was 70 (range, 40-90). Eight patients had low-grade gliomas and four patients had anaplastic astrocytomas. Eight patients received radiation treatment to the brain as the only treatment, and four received neither radiation nor chemotherapy. The median dose of megavoltage radiation was 55.4 Gy (range, 45-61.2 Gy). Of the eight patients who received brain radiotherapy, the clinical and radiologic follow-up findings improved in three patients, stabilized in three patients, and worsened in two patients. Median follow-up was 10.3 months (range, 1-55 months). The median survival for the eight patients who received brain radiotherapy was 11.4 months. The one- and two-year survival rates were 45% and 30%, respectively. Two of the eight patients who received radiotherapy were alive at the time of writing. The four patients who did not receive radiotherapy died of the disease at 0.6, 1.0, 1.9, and 2.4 months after diagnosis.

CONCLUSIONS

Gliomatosis cerebri is associated with poor survival. Although brain radiotherapy controlled or stabilized disease progression in most patients, the overall survival after brain radiotherapy alone was not satisfactory. More aggressive therapy may be needed.

Gliomatosis cerebri: molecular pathology and clinical course

Gliomatosis cerebri is a rare, diffusely growing neuroepithelial tumor characterized by extensive brain infiltration involving more than two cerebral lobes. Among 13 patients with gliomatosis cerebri (median age, 46 years), biopsies showed features of diffuse astrocytoma (n = 4), oligoastrocytoma (n = 1), anaplastic astrocytoma (n = 5), anaplastic oligoastrocytoma (n = 1), or glioblastoma (n = 2). Molecular genetic investigation showed TP53 mutations in three of seven tumors and both PTEN mutation and epidermal growth factor receptor overexpression in one tumor. Amplification of CDK4 or MDM2 or homozygous deletion of CDKN2A was not detected. Three of 10 patients receiving radiotherapy showed a partial response (one patient) or had stable disease (two patients) lasting for more than 1 year. Four of six patients treated with procarbazine, carmustine, vincristine chemotherapy demonstrated partial remission (one patient), minor response (two patients), or stable disease (one patient). Median survival time from diagnosis was 14 months (range, 4-91+ months). Infratentorial involvement was associated with shorter survival. We conclude that (1) the molecular genetic alterations in gliomatosis cerebri resemble those in diffuse astrocytomas; (2) the prognosis of gliomatosis cerebri is variable but for at least 50% of patients as poor as for glioblastoma; and (3) some patients respond to radiotherapy and/or procarbazine, carmustine, vincristine chemotherapy.

Gliomatosis cerebri: pitfalls in diagnosis

We report two young patients with obscure presentations of gliomatosis cerebri. Initial CT scanning was inconclusive and in one case showed intraventricular haemorrhage, a feature not previously described. Magnetic resonance imaging was required to show the lesions with greater definition; however, in both cases, a biopsy was needed to confirm the diagnosis.

Serial positron emission tomography (PET) in gliomatosis cerebri treated with radiotherapy: a case report

Results of serial positron emission tomography (PET) in a biopsy-proven case of gliomatosis cerebri (GC) are reported. Computed tomography (CT) with and without contrast failed to detect focal abnormalities, but magnetic resonance (MR) revealed iso-intensity or low-intensity lesions in T1-weighted images and high-intensity lesions in T2-weighted images. Lesions were seen in the left thalamus, right temporal lobe and claustrum, and pons. Radiotherapy remarkably improved clinical and imaging findings. Both before and shortly after radiotherapy, 11C-methionine PET images showed hypermetabolism while 15O-water PET images showed a marked increase in cerebral blood flow in GC lesions. However, 6 months later PET images had remarkably improved, appearing nearly normal.