Medulloblastoma or cerebellar dysplastic gangliocytoma (Lhermitte-Duclos disease)?

Dysplastic cerebellar gangliocytoma is a rare benign tumor associated with specific neuroimaging findings of abnormal laminated or folial pattern in the posterior fossa. Some authors thus proposed that it could be diagnosed by neuroimaging studies alone. We encountered a patient with medulloblastoma in which the neuroimaging findings mimicked those of dysplastic gangliocytoma. In patients with a posterior fossa tumor suggestive of a dysplastic gangliocytoma on neuroimaging studies, a pathologic confirmation is necessary.