Gliomatosis cerebelli, an infantile cerebellar neoplasm that exhibited diffuse infiltration without forming a mass

[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.

Diffuse paediatric cerebellar glioma: two identical imaging phenotypes of an extremely rare entity with disparate pathology

Although the posterior fossa is a common location for paediatric brain tumours [1], diffuse glioma isolated to the cerebellum is an extremely rare imaging entity. Only two cases of isolated diffuse paediatric cerebellar glioma have been reported in the English language to the best of our knowledge [2, 3], and only one of these cases had a similar imaging phenotype to our cases [3]. Although somewhat similar to Lhermitte-Duclos (dysplastic gangliocytoma of the cerebellum), the appearances are distinct from other neoplastic entities of the paediatric posterior fossa. Clinical presentation and neurological examination findings are vital however to help differentiate other diffuse pathologies involving the cerebellum such as rhombencephalitis. Presented here are two diffuse cerebellar gliomas in children under the age of 3 with near identical imaging phenotypes demonstrating differing histological and molecular genetic profiles.

"Gliomatosis encephali" as a novel category of brain tumors by the first autopsy case report of gliomatosis cerebelli

Gliomatosis cerebri is a rare diffuse glioma that is neither mass-forming nor necrotic, and does not disrupt existing structures. Gliomatosis occurring in the cerebellum is known as gliomatosis cerebelli, and only three such cases examined by biopsy have been reported. Here we describe the first autopsy findings of a patient who was diagnosed as having gliomatosis in the cerebellum. Neuropathological examination identified the tumor cells as being positive for glial fibrillary acidic protein, vimentin and nestin, with atypical nuclei that were cashew-nut- or dishcloth-gourd-shaped. These tumor cells were dense in the right cerebellum, but also spread broadly throughout the brain including the left cerebrum and optic nerve. Mitotic figures were frequently seen in the cerebellum, brain stem and cerebrum. Scherer's secondary structures were evident not only in the cerebellum but also the cerebrum. No necrosis, microvascular proliferation or destruction of anatomical structures was detected in the whole brain. Differences in the origin of the tumors of the gliomatoses cerbri and cerebelli suggests these tumors are different types of brain tumors. Thus the findings support that the gliomatosis cerebelli is a novel type of brain tumor classification. Furthermore, by the similarities of the histological features among the tumors, it appears appropriate to establish a novel category of "gliomatosis encephali" which includes both gliomatosis cerebri and gliomatosis cerebelli.