Evaluation of molecular genetic alterations associated with tumor progression in a case of gliomatosis cerebri

Pediatric Gliomatosis Cerebri: A Review of 15 Years

Gliomatosis cerebri is a rare glial tumor that carries a poor prognosis. Seen in both adults and children, gliomatosis cerebri appears to differ in these populations as with adult versus pediatric glioblastoma. We present 10 children who either presented to the Weill Cornell Medical College or enrolled in the institution's Gliomatosis Cerebri International Registry alongside a cohort of 89 pediatric patients reported in the literature between 2000 and 2014. Age ranged from 4 months to 21 years, with a male to female ratio of 1.71. Median overall survival for patients in the registry cohort was 17 months (n = 10) and for the historic cohort was 13 months (n = 52). Overall survival was analyzed for the combined cohort and was significantly longer when presenting at age ≥ 10 (20 vs 10 months), for boys (18 vs 11 months), and with low-grade pathology (26.5 vs 12 months) but did not vary significantly by treatment approach.

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.

Cerebellar gliomatosis in a toddler: case report of a challenging condition and review of the literature

Gliomatosis confined to the cerebellum is most unusual. We report such a case in a 20-month-old male who presented with unsteadiness. Magnetic resonance imaging revealed a diffuse area of abnormal signal intensity within both cerebellar hemispheres, which did not enhance after contrast administration. The patient underwent a biopsy, which revealed a diffuse glioma infiltrating the cerebellum. Overall, the tumor cells had oligodendroglioma-like features and exhibited only focal vimentin immunoreactivity. They were negative for glial fibrillary acidic protein, synaptophysin, βIII-tubulin, and neurofilament protein. Immunofluorescence, performed on primary biopsy explants maintained in cell culture without exposure to growth factors or differentiation-promoting agents, revealed widespread nestin immunoreactivity and immunolabeling of occasional cells with antibodies to platelet-derived growth factor-α and O1/O4, markers of oligodendrocyte precursor-cells and immature oligodendrocytes, respectively. Fluorescent in situ hybridization performed on explants, touch preparations, and paraffin sections failed to reveal loss of heterozygosity for either 1p36 or 19q13. The patient was treated with temozolomide and remains stable, albeit with residual quiescent tumor, more than 3 years after surgery. This report calls attention to an unusual presentation of gliomatosis confined to the cerebellum of a toddler and addresses salient aspects of clinical and radiological differential diagnosis, as well as therapeutic challenges encountered.

[Gliomatosis cerebri]

INTRODUCTION

gliomatosis cerebri (GC) is a rare, diffusely growing glial tumour characterized by extensive brain infiltration. The diversity of histological subtype and grade on presentation among different subjects, in addition to the usually poor response to treatment make GC an uncertain entity where many questions still remain unanswered. One article in this issue of NEUROLOGIA describes a series of 22 patients with GC, where clinical, therapeutic and outcome results are detailed.

DEVELOPMENT

clinical presentation of GC is non-specific and, although the neuroimage is characteristic, the spectrum of differential diagnosis is wide. Despite the fact that known prognostic factors in glioma also seem to be involved in GC, the heterogeneity of pathology and molecular findings on biopsy samples makes it difficult to characterise GC correctly. Therefore, variability of outcome and response to therapy is the rule. Evidence on therapeutic strategies is based on case-series. According to this, the optimal treatment is not well established. Part of current research is focused on identifying molecular predictor factors of response to chemotherapy.

CONCLUSIONS

the addition of chemotherapy in the classic treatment schedule based on radiotherapy seems to produce better responses in GC patients. However, the outcome of these patients remains poor with low survival rates. Phase III multi-centre trials to evaluate different therapeutic strategies in GC are essential. Further knowledge on the histological profile and molecular prognostic factors is also required. Patients should be stratified according to the prognostic factors identified.

Gliomatosis cerebri, imaging findings of 12 cases

BACKGROUND AND PURPOSE

We report 12 cases of Gliomatosis cerebri (GC), a rare brain neoplasm, to define its semeiologic criteria. Literature was reviewed to clarify its physiopathology.

PATIENTS AND METHODS

From 1997 to 2008, 12 histologically proven cases with GC were retrospectively reviewed. Of the 12 patients, nine were male. The mean age was of 54 years. Were performed CT-Scan (n=6), MRI (n=12), diffusion and perfusion weighted images (n=12 and n=4), MR Spectroscopy (n=3), a FDG and a Methionin PET-Scan (n=2 and n=3 respectively).

RESULTS

Primary diagnosis was missed in six cases. Most frequent clinical signs were seizure and mental changes. Imaging criteria were: area of high signal intensity on FLAIR and T2-weighted images, involving three or more contiguous lobes with conserved architecture. Frequently a bilateral widespread invasion with involvment of the corpus callosum or the anterior white commissure or both was observed. At diagnosis and in the classical form (type I) of GC, no significant contrast enhancement and decreased rCBV were observed. Focal enhancement and increased rCBV were observed in the focal mass in type II GC. MR Spectroscopy showed an increase of the Cho/Cr ratio and a decrease in the NAA/Cr one. FDG PET showed in type I a decreased avidity for the FDG whereas in type II a increased avidity was observed. MET-PET showed an increased avidity for the tracer in a GC type II and a slight avidity in a GC type I.

CONCLUSION

GC is a rare brain entity. Primary diagnosis is often missed. The imaging findings of GC I, a WHO grade III tumor, should be known and include classical MRI but also PWI, MRS and scintigraphic findings.

Array-based comparative genomic hybridization and immunohistochemical studies in gliomatosis cerebri

Gliomatosis cerebri (GC) are extensively infiltrative glial tumors classified as astrocytic tumors in the current World Health Organization (WHO) classification scheme. In investigating the tumorigenesis of GC, we reviewed 28 cases of GC immunohistochemically and carried out array-based comparative genomic hybridization (CGH) in ten of those cases. In histological and immunohistochemical review, 18 cases (64%) were of astrocytic lineage, three (11%) were of oligodendroglial lineage, and seven (25%) were of uncommitted lineage. In the array-based CGH, 52 clones were frequently lost on 6p, 9p, and 9q in more than six cases, and six clones were frequently gained on 1p, 6q, 10q, and 21q in more than three cases. Some gained or lost genetic loci differed significantly between the histologically high-grade and low-grade GC (P < 0.05), but unsupervised hierarchical clustering failed to produce evidence of any clinical significance. These altered genetic foci are not known to be involved in the development of conventional glial tumors, including astrocytic tumors. In conclusion, despite the dominant astrocytic differentiation of GC histologically, novel genomic aberrations found in our GC cases were different from those of astrocytic tumors.