We report the case of a two years old, normally eating child, affected by organic macies and severe dystrophy. After the negative response of blood and laboratory examinations let us exclude a malabsorption syndrome, only the performance of neuro-radiologic exams showed evidence of a subthalamic tumor as the cause of a "Diencephalic syndrome". Diencephalic syndrome or Russell's syndrome is a diencephalic tumor induced disease, which sets in the first time of life. The disease clinical markers are a severe emaciation with appetite preservation and absence or very scarce evidence of any telltale neurological sign. The tumoral histo-pathology most frequently shows a low grade of malignancy astrocytoma, whose eradication is very often difficult because of particular anatomic site. Treatment of choice includes an excisional biopsy with chemotherapy and radiotherapy. We report a clinical case of long-term survival and review of the literature.