Craniopharyngioma presenting a symptom of pituitary apoplexy and hyponatremia: a case report

We report a case of a 70-year-old woman admitted to our hospital with sudden headache, drowsiness and hyponatremia. MRI on admission showed an intrasellar mass with suprasellar extension. Serum examination revealed decreased sodium and hypopituitarism, but they were normalized gradually by compensation using hydrocortisone, thyroid hormone and salt. Afterwards, masked diabetes insipidus appeared and required aqueous pitressin for the control of urine volume. A removal operation was performed uneventfully using the transsphenoidal approach and histological examination confirmed squamous-papillary type craniopharyngioma. Intratumoral hemorrhage of the craniopharyngioma is extremely rare. These cases tend to occur after over 15 years of maturation and the squamous-papillary type tend to bleed more than the adamantinomatous type. However, it is very difficult to make a differential diagnosis between craniopharyngioma with intratumoral hemorrhage and pituitary apoplexy, judging only by symptoms or interventional radiology. The definite mechanism of hyponatremia associated with a parasellar lesion is still obscure, but compression to the anterior hypothalamus or pituitary gland by an enlargement of the parasellar tumor is generally hypothesized.