Diffusely Infiltrating Cerebellar Anaplastic Astrocytoma Effectively Controlled with Bevacizumab: Case Report and Literature Review

[Diffuse infiltrating primary cerebellar glioma involving the brainstem: a case report]

An 85-year-old woman was admitted to our hospital with unsteady gait, dizziness, nausea, and vomiting. MRI revealed characteristic abnormal signals in the bilateral cerebellar hemispheres. A brain biopsy was performed which confirmed a definitive histological diagnosis of diffuse glioma. Follow-up MRI showed diffuse abnormal signals that extended from the cerebellum to the brainstem through the cerebellar peduncle without mass formation. Her general condition gradually deteriorated even with the best supportive care, and she died 195 days after admission. Gliomatosis cerebri is characterized by a diffuse infiltrating growth pattern without mass formation in the brain. This case showed a similar proliferation mode from the cerebellum to the brain stem without mass formation. This case was diagnosed based on MRI and pathological findings. Only five similar cases have been previously reported, and compared to these reports, the patient in the present case was the oldest with the poorest prognosis. The histopathological features may influence the appropriate treatment and the prognosis. This disorder is a very rare condition; thus, when we encountered this patient showing cerebellar ataxia with diffuse abnormal MRI signals without mass formation in the cerebellum and brainstem, a brain biopsy was necessary to establish the definitive diagnosis.

Cerebellar anaplastic astrocytoma in adult patients: 15 consecutive cases from a single institution and literature review

Adult cerebellar anaplastic astrocytomas (cAA) are rare entities and their clinical and genetic appearances are still ill defined. Previously, malignant gliomas of the cerebellum were combined and reviewed together (cAA and cerebellar glioblastomas (cGB), that could have possibly affected overall survival (OS) and progression-free survival (PFS). We present characteristics of 15 adult patients with cAA and compared them to a series of 45 patients with a supratentorial AA (sAA) in order to elicit the effect of tumor location on OS and PFS. The mean age at cAA diagnosis was 39.3 years (range 19-72). A history of neurofibromatosis type I was noted in 1 patient (6.7%). An IDH-1 mutation was identified in 6/15 cases and a methylated MGMT promoter in 5/15 cases. Patients in study and control groups were matched in age, sex and IDH-1 mutation status. Patients in a study group tended to present with longer overall survival (50 vs. 36.5 months), but the difference did not reach statistical significance. In both cAA and supratentorial AA groups presence of the IDH-1 mutation remains a positive predictor for the prolonged survival. The present study suggests that adult cAA constitute a group of gliomas with relatively higher rate of IDH-1 mutations and prognosis similar to supratentorial AA. The present study is the first to systematically compare cAA and supratentorial AA with respect to their genetic characteristics and suggests that both groups show a similar survival prognosis.