[Cerebellar gangliocytoma in an 11-year-old child].

Cerebellar gangliocytoma can correspond to Lhermitte-Duclos disease, a benign hamartomatous malformation encountered in young adults. It can also be a part of gangliogliomas/gangliocytomas family, which usually encompasses temporal pediatric neoplasms associated with longstanding seizures. We report a case of a young 11-year-old patient who presented with a gangliocytoma of the cerebellum revealed by neurologic manifestations (headache, dyspraxia, equilibrium and gait disturbances). Diagnosis was made on surgical material. Tumour was characterized by dysplastic mature ganglion cells, perivascular lymphocytic infiltrates and no glial neoplastic component. By immunohistochemistry, ganglion cells expressed neurofilaments, MAP2 protein, synaptophysin, chromogranin A and S100 protein. BRAF V600E mutation was absent. Clinical characteristics, radiology, histopathology of the two main diagnoses are discussed.