[Primary hypothalamic tumors (excluding craniopharyngioma). Endocrine and post-radiotherapy development study. Apropos of 17 cases].

The authors underline a number of features of primary hypothalamic tumours (except craniopharyngioma) based on a study of 17 cases: The vital prognosis is satisfactory; only one death was observed with an average follow-up period of 80 months (range 1 to 17 years). This raises the question of the necessity for systematic biopsy to confirm the tumour histology (although when performed in conditions of stereotaxis there are no serious risks). The site of the tumour makes surgery difficult and complete ablation impossible. As many hypothalamic tumours, including the pilocytic astrocytoma which is the commonest type, are sensitive to radiotherapy, this would seem to be the treatment of choice. Total regression is observed in the majority of cases. From the endocrine point of view, the mediocre prognosis is aggravated by high energy radiotherapy. However, with the present therapeutic methods, it is relatively easy to compensate complete or dissociated deficits. There is an endocrine syndrome suggestive of hypothalamic tumour which consists of anterior pituitary deficiency, diabetes insipidus and moderate hyperprolactinaemia (20 to 100 ng/ml). Close medical surveillance is essential, both of the local (visual field and frontal CT scanning) and endocrine effects. Hormonal deficits may occur as a late complication up to 5 years after radiotherapy. The problems inherent to hypothalamic tumours: neurogenic hypernatraemia which is luckily uncommon, with an unexplained weight gain occurring during substitute therapy for adrenal insufficiency with physiological doses of hydrocortisone. Finally, the overall prognosis is good with a minimum of complications due to radiotherapy, excepting endocrine deficiency, providing a dose of 60 grays in 6 weeks at 2 grays per session is not exceeded.