Cerebellar liponeurocytoma
Cerebellar liponeurocytomas, also known as neurolipocytomas, are rare tumors of the cerebellum with neurocytic differentiation and abundant intracellular lipid. They are considered WHO grade II tumors .
Epidemiology
These tumors have been reported at a wide range of ages (4-77 years) but seem to be encountered typically in adults of middle age . There is no strong gender predilection .
Clinical presentation
The clinical presentation is non-specific, relating to raised intracranial pressure (e.g. headache) and cerebellar signs (e.g. ataxia) .
Pathology
Location
As the name implies, the vast majority of cases of liponeurocytoma arise in the cerebellum . However, up to a fifth of reported cases have been supratentorial, around or within the ventricular system .
Classification
They are considered a WHO grade II neuronal/neurocytic tumor in the current (2016) WHO classification of central nervous system tumors .
Microscopic features
These tumors are composed of small neurocytic cells and neuroepithelial cells with abundant cytoplasmic lipid .
Immunophenotype
- synaptophysin: positive
- neuron-specific enolase: positive
- MAP2: positive
- GFAP: positive
Radiographic features
Cerebellar liponeurocytomas appear as heterogeneous intra-axial or, uncommonly, intraventricular masses . The most common location is in the cerebellar hemispheres.
CT
The tumor is usually hypodense but occasionally isodense to surrounding parenchyma .
MRI
- T1: more commonly hypointense, sometimes isointense, only occasionally hyperintense to suggest macroscopic fat (18%)
- T2/FLAIR: usually hyperintense
- T1 C+: heterogeneous enhancement
PET
The tumor shows high C-11 methionine uptake but lower F-18 FDG uptake than normal brain cortex .
Treatment and prognosis
The tumor can be cured with complete tumor resection and adjuvant radiotherapy . However, recurrence is common with incomplete tumor resection followed by radiotherapy (17%) or with complete tumor resection without adjuvant radiotherapy (26%) .
