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 2 tumors ¹. 

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 ^1,2. There is no strong gender predilection ^1,2.

Clinical presentation

The clinical presentation is non-specific, relating to raised intracranial pressure (e.g. headache) and cerebellar signs (e.g. ataxia) ¹.

Pathology

Location

As the name implies, the vast majority of cases of liponeurocytoma arise in the cerebellum ². However, up to a fifth of reported cases have been supratentorial, around or within the ventricular system ².

Classification

They are designated as WHO grade 2 tumors and considered one of the glioneuronal and neuronal tumors in the WHO classification of central nervous system tumors ^1,2,4.

Microscopic features

These tumors are composed of small neurocytic cells and neuroepithelial cells with abundant cytoplasmic lipid ¹.

Immunophenotype

• synaptophysin: positive
• neuron-specific enolase: positive
• MAP2: positive
• GFAP: positive

Radiographic features

Cerebellar liponeurocytomas appear as heterogeneous intra-axial or, uncommonly, intraventricular masses ². The most common location is in the cerebellar hemispheres.

CT

The tumor is usually hypodense but occasionally isodense to surrounding parenchyma ².

MRI

• T1: more commonly hypointense, sometimes isointense, only occasionally hyperintense to suggest macroscopic fat (18%) ²
• T2/FLAIR: usually hyperintense ²
• T1 C+: heterogeneous enhancement ^1,2

PET

Cerebellar liponeurocytomas demonstrate high C-11 methionine uptake but lower F-18 FDG uptake than normal brain cortex ³.

Treatment and prognosis

Cerebellar liponeurocytomas can be cured with complete resection and adjuvant radiotherapy ². However, recurrence is common with incomplete resection followed by radiotherapy (17%) or with complete resection without adjuvant radiotherapy (26%) ².