Midline cerebellar medulloblastoma in a seventy-one-year-old patient.
BACKGROUND
Medulloblastoma is the most common malignant central nervous system tumour in children but, in contrast, quite rare in adults. Hemispheric, rather than midline, cerebellar medulloblastomas are more common in older children and adults. We present the unusual case of a 71-year-old man who presented with a fourth ventricular mass that proved to be a medulloblastoma.


METHODS
A 71-year-old man presented with progressive balance problems, slurred speech and double vision. A CT scan of the brain revealed a hyperattenuating, partially calcified, avidly enhancing mass within the fourth ventricle. Diffusion weighted MRI showed restricted diffusion within the mass. The patient underwent a midline suboccipital craniotomy and a subtotal resection was achieved.


RESULTS
Histological examination showed a densely cellular neoplasm composed of small cells with a tendency towards neuroblastic rosette formation. Most cells were strongly positive for neuron-specific enolase and synaptophysin. Ultrastructurally, tumour cells showed evidence of neuronal differentiation. These findings were consistent with a classical medulloblastoma.


CONCLUSIONS
Adult medulloblastoma should be considered in the differential diagnosis of a partially calcified hyperattenuating mass within the fourth ventricle.
Division of Neurosurgery, Department of Surgery, University of British Columbia, Vancouver, Canada.
Raymund L
RL
Yong
Eoin C
EC
Kavanagh
David
D
Fenton
Katerina
K
Dorovini-Zis
Manraj K S
MK
Heran
Charles S
CS
Haw
D000368:Aged; D001932:Brain Neoplasms / Q000473:pathology; D002528:Cerebellar Neoplasms / Q000378:metabolism / Q000473:pathology*; D002551:Cerebral Ventricle Neoplasms / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging; D020546:Fourth Ventricle / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008527:Medulloblastoma / Q000378:metabolism / Q000473:pathology*; D046529:Microscopy, Electron, Transmission; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D016708:Synaptophysin / Q000378:metabolism; D014057:Tomography, X-Ray Computed
D016708:Synaptophysin; D010751:Phosphopyruvate Hydratase