The now nine years old girl with growth retardation, started to be ill with otitis and then diabetes insipidus of central origin at 1974. A treatment with lysin-vasopressin is prescribed. The PNEG in May 1976 shows a little, pea like, suspicious, supra-sellar nodule who is not surgically explored since they was no ophtalmologic symptoms and because a normal CT scan. Corticoid and thyroid substitutive therapy is added until September 1977 when the general status becomes impaired and vomiting starts. Also because some visual loss, a new neuroradiological study is performed showing a supra-sellar tumour and a fourth ventricle mass. The CT scan asserts the double intracranial expansive process and a posterior fossa craniotomy is done with subtotal resection of a vermian tumour and Torkildsen drainage. The histology is : Immature Dysembryoma (seminoma type) or germinoma. The follow-up was good under hormonal care. X Rays Therapy over the posterior fossa, the suprasellar region, the brain and the spinal channel was instaured. Four months later, the CT scan shows normal sized ventricles and no tumour mass at all. This case gives the authors opportunity for comments and to study the concerned literature.