[Germinoma responsible for central diabetes insipidus]

We report the case of a 20-year-old woman who presented with sudden onset of polydipsia and polyuria. A diagnosis of diabetes insipidus was confirmed and the MRI showed a pituitary stalk enlargement. The patient was treated with Minirin. Two years later, she developed a panhypopituitarism. The MRI showed an intrasellar mass with an enlargement of the pituitary gland. A biopsy confirmed a germinoma. The patient was treated with radiotherapy with a partial response as only a part of the mass disappeared. This case highlights the importance of the clinical and radiological follow-up of central diabetes insipidus, especially when it is of unknown origin. The differential diagnosis will be reviewed.