PURPOSE To characterize the MR findings of glioblastoma multiforme in the posterior fossa. METHODS MR studies of nine patients with surgically proved posterior fossa glioblastoma multiforme were retrospectively evaluated. MR characteristics studied included tumor location, signal intensity, enhancement pattern, and presence of intratumoral hemorrhage, as well as presence of secondary hydrocephalus or metastatic spread. RESULTS The tumors were located in the median portion of the cerebellum or brain stem in eight cases. Six extended into the fourth ventricle. Hydrocephalus was seen in four cases. Six cases demonstrated decreased T1- and increased T2-weighted signal intensities. Three cases demonstrated mixed signal intensities suggesting intratumoral hemorrhage. All of the eight patients who received contrast showed moderate to marked heterogeneous ringlike enhancement suggesting intratumoral necrosis. Multicentric/multifocal lesions or extraaxial metastases were identified in three of the nine cases, and there was extracranial extension into the cervical region in one case. CONCLUSION Glioblastoma multiforme is a rare tumor in the posterior fossa. Differentiating it from metastatic tumor or malignant astrocytoma was difficult. However, combination of heterogeneous and ringlike enhancement, midline location, poorly defined margin, tumoral hemorrhage, concomitant multicentric/multifocal lesions, and extraaxial or extracranial metastasis may be clues for the prospective diagnosis of glioblastoma multiforme.

http://www.ajnr.org/content/ajnr/16/3/583.full.pdf

Posterior fossa glioblastoma multiforme: MR findings.

Pediatric high-grade gliomas represent approximately 10% of all pediatric brain tumors. Similar to adult high-grade gliomas, they behave very aggressively, and these children have a very poor prognosis despite a variety of therapies that include chemotherapy and radiotherapy. In this review, we present an overview of both pediatric high-grade gliomas and diffuse intrinsic pontine gliomas with a focus on their epidemiology, etiology, presentation, prognostic factors, biology, treatment modalities, outcomes, and future research directions.

Pediatric High-Grade Gliomas and Diffuse Intrinsic Pontine Gliomas

A phase II study was conducted to assess the efficacy of administering daily thalidomide concomitantly with radiation and continuing for up to 1 year following radiation in children with brain stem gliomas (BSG) or glioblastoma multiforme (GBM). Secondary objectives were to obtain preliminary evidence of biologic activity of thalidomide and to evaluate toxicities from chronic administration of thalidomide in this population.

Phase II study of thalidomide and radiation in children with newly diagnosed brain stem gliomas and glioblastoma multiforme

More than 10 years ago, the goal of our work had been to obtain a tissue sample of infiltrating lesions of the brainstem that had been diagnosed using computerized axial tomography (CAT). At that time, biopsies were believed to be indispensable when starting treatment of tumors. With time our objectives changed. Biopsies remained necessary, since until 1 year before the writing of this article we had not had the benefits of magnetic resonance imaging (MRI) at our Hospital. We also decided that carrying out sound statistics, confirmed by biopsies, was in itself a good procedure, especially in a country in which, to date, no serial studies of brainstem tumors had been undertaken. We analyzed all of the patients diagnosed with posterior fossa tumors between March 1989 and March 2002 at the Hospital Infantil de Mexico Federico Gomez (HIM). A preoperative TAC of the cranium was performed on every patient. Stereotactically-guided biopsies during tomography allowed precise control of penetration. Material obtained was sent to the Department of Pathology for analysis. Fifty patients were diagnosed with infiltrating tumors of the brainstem: 30 cases of low-grade astrocytomas, 13 cases of high-grade astrocytomas, 2 cases of primitive neuroectodermic tumors, 2 cases of rhabdoid tumors, 1 case of ependymoma, and 2 patients had non-specified tumors. The most frequent symptoms and signs were ataxia and disturbances of the cranial nerves. There was no mortality caused by penetration, and follow-up studies of more than 5 years were carried out. The results from our series were similar to those in the literature. In our case, follow-up studies were undertaken for longer periods. In the first section of our work, we suggest the need for stereotactic biopsies in order to arrive at a precise diagnosis in environments in which MRI may be unavailable. At present, presumptive diagnosis of infiltrating brainstem lesions may be adequately undertaken with imaging methods, such as MRI. However, we believe that a stereotactically-guided biopsy provides an accurate method for diagnosing lesions of the brainstem. In our case, this procedure has been carried out entirely in the tomography room, without any complications of disease or mortality.

Stereotactically-guided biopsies of brainstem tumors.

The incidence of solitary brain stem abscess is less than 4% of all posterior fossa abscesses, and probably less than 1% of all intracranial abscesses. Two cases are reported, both presenting as chronic progressive clinical problems and initially diagnosed as gliomas. It is suggested that aspiration is a more suitable treatment than excision, and that in cases secondary to otogenic disease, radical mastoidectomy might have been an adequate method of prophylaxis.

https://jnnp.bmj.com/content/jnnp/40/7/625.full.pdf

Pellet W

Papers

Brain stem tumors