下垂体卒中様症状で発症し低ナトリウム血症を呈した頭蓋咽頭腫の1例

Craniopharyngioma Presenting a Symptom of Pituitary Apoplexy and Hyponatremia : a case report

I．はじめに

　下垂体腫瘍内出血による卒中様症状は臨床上しばしばみられるが，頭蓋咽頭腫の腫瘍内出血はきわめて稀である^3）．下垂体卒中様症状に引き続き下垂体機能低下症および低ナトリウム血症を起こした頭蓋咽頭腫の1例を経験したので若干の文献的考察を加え報告する．

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 ex-amination revealed decreased sodium and hypopituitarism, but they were normalized gradually by com-pensation 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 un-eventfully 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 adamantinoma-tous 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 com-pression to the anterior hypothalamus or pituitary gland by an enlargement of the parasellar tumor is generally hypothesized.