Around 75% of the brainstem gliomas are diagnosed in children and young adults under the age of twenty, but have been known to affect older adults as well.
Brainstem gliomas start in the brain or spinal cord tissue and typically spread throughout the nervous system.
Brainstem gliomas are often primary brain tumors, and rarely metastasize, or spread, to affect another part of the body.
Seven patients had a transventricular biopsy of the brainstem performed. Of those, five were pediatric patients. The median age was 10 years (range: 3-26 years). Five of them were female and two male. Four patients presented with secondary obstructive hydrocephalus. The main clinical presentations were intracranial hypertension syndrome in four patients, motor neuron disease in four patients, two with decreased state of alertness, two with gait ataxia, and one with Parinaud syndrome. The types of tumors found in the histopathology and their location were one ventral (pons) and one aqueductal anaplastic astrocytoma, two ventral, one aqueductal, and one attached to the floor of the fourth ventricle pilocytic astrocytoma and one ventral low-grade astrocytoma. The route taken to approach the ventral tumors was made through premammillary fenestration. The tumors of the aqueduct and floor of the fourth ventricle were approached transaqueductally. ConclusionâThe use of flexible endoscops for biopsy of ventral, dorsal (tectum lamina quadrigemina), and diffuse brainstem tumors is a useful, effective, and safe procedure that also allows to treat obstructive hydrocephalus secondary to the tumors 1).
Genetically engineered mice are commonly used to model brainstem gliomas in pre-clinical research. One technique for inducing primary tumors in these genetically engineered mice involves delivering viral vectors containing the code for gene-editing proteins. Weidenhammer et al. present a protocol for generating primary brainstem gliomas using the RCAS-TVA retroviral delivery system and the Cre/loxP gene editing system. They describe steps for transfecting and harvesting chicken fibroblast cells, intracranially injecting cells into mice, imaging primary tumors, and treating primary tumors with focal, image-guided brain irradiation 2).
Maxwell et al. used The Surveillance, Epidemiology and End Results (SEER) database to conduct a population-based study on pediatric patients with histologically confirmed anaplastic astrocytoma or glioblastoma tumors located within the brainstem. Multivariate analysis incorporating patient demographics, tumor characteristics, and treatments were used to determine predictors of cancer-specific mortality and survival at 6 months, 9 months, 1 year, and 2 years.
They included 154 patients from the SEER database - 72 (47%) anaplastic astrocytoma and 82 (53%) glioblastoma patients. Median survival for the entire cohort was 10.0 months. Glioblastoma histology, developmental stage, and large tumor size were significantly associated with cancer-specific mortality. Six-month, 9-month, 1-year, and 2-year survival rates were 75%, 57%, 42%, and 20%, respectively. Glioblastoma histology was associated with worsened survival at 6 months (OR=0.19, p=0.0081), 9 months (OR=0.18, p< 0.001), 1 year (OR=0.19, p< 0.001), and 2 years (OR=0.14, p=0.0055). Radiation therapy was associated with improved survival at 6 (OR=8.53, p=0.0012) and 9 months (OR=3.58, p=0.035) but not at 1 or 2 years. Radiation therapy was associated with improved survival in glioblastoma (9.0 vs. 3.0 months, p< 0.001).
This population-based study demonstrated that glioblastoma histology is associated with a poor prognosis in pediatric patients with brainstem high-grade gliomas. Regardless of histology, radiation therapy improved survival at 6 and 9 months but not long-term. 3).
Seven patients had a transventricular biopsy of the brainstem performed. Of those, five were pediatric patients. The median age was 10 years (range: 3-26 years). Five of them were female and two male. Four patients presented with secondary obstructive hydrocephalus. The main clinical presentations were intracranial hypertension syndrome in four patients, motor neuron disease in four patients, two with decreased state of alertness, two with gait ataxia, and one with Parinaud syndrome. The types of tumors found in the histopathology and their location were one ventral (pons) and one aqueductal anaplastic astrocytoma, two ventral, one aqueductal, and one attached to the floor of the fourth ventricle pilocytic astrocytoma and one ventral low-grade astrocytoma. The route taken to approach the ventral tumors was made through premammillary fenestration. The tumors of the aqueduct and floor of the fourth ventricle were approached transaqueductally.
The use of flexible endoscops for biopsy of ventral, dorsal (tectum lamina quadrigemina), and diffuse brainstem tumors is a useful, effective, and safe procedure that also allows to treat obstructive hydrocephalus secondary to the tumors 4).
A 23-year-old woman was referred to our department with a chief complaint of headache for six months. Magnetic resonance imaging (MRI) showed diffuse T2 hyperintense swelling of the brainstem with the pons as the main locus. Enlargement of the lateral ventricles was observed because of cerebrospinal fluid obstruction out of the posterior fossa. This was atypical for a diffuse midline glioma in terms of the longstanding slow progression of symptoms and patient age. Stereotactic biopsy was performed for diagnosis, and foramen magnum decompression (FMD) was concomitantly performed to treat the obstructive hydrocephalus. The histological diagnosis was astrocytoma, IDH-mutant. Post-surgery, the patient's symptoms were relieved, and she was discharged on the fifth day after surgery. The hydrocephalus was resolved, and the patient returned to normal life without any symptoms. The tumor size follow-up with MRI demonstrated no marked change for 12 months. Even though diffuse midline glioma is considered to have a poor prognosis, clinicians should contemplate if it is atypical. In atypical cases like the one described herein, surgical treatment may contribute to pathological diagnosis and symptom improvement 5).