RESUMEN
Central diabetes insipidus caused by pineal gland neoplasm is rare. Here, we describe a case of central diabetes insipidus and pineal germinoma with seeding to pituitary stalk along CSF pathway. A 27 year-old male patient was admitted due to polyuria, polydipsia, headache, vomiting, diplopia, and decreased visual acuity for recent two months. Urine osmolality measured after water deprivation was below 100mOsm/kg. However, urine osmolality increasd above 300 mOsm/kg with pitressin administration. Brain MRI showed a 2cm sized mass with seeding into pituitary stalk along CSF in pineal region. Surgical biopsy revealed pineal germinoma. Two cycles of chemotherapy with etoposide and cis-platin were done followed by brain irradiation(2,500cGy). Follow up brain MRI after second chemotherapy showed complete remission. The patient had no neurologic and endocrinologic deficit after the treatment.