ラトケ囊胞と非機能性下垂体腺腫が合併した1例

A Case of Non-functional Pituitary Adenoma Associated with Rathke's Cleft Cyst

Ⅰ．はじめに

　ラトケ囊胞は大部分がRathke's pouchの遺残から発生する非腫瘍性鞍内囊胞であり，以前は稀な疾患とされていたが，近年少なからず報告されている．しかしラトケ囊胞と下垂体腺腫が合併した報告は少なく，特に非機能性下垂体腺腫との合併例はわれわれが渉猟し得た範囲では過去に1例のみである．今回われわれは，ラトケ囊胞と非機能性下垂体腺腫が合併した稀な1例を経験したので，文献的考察を加え報告する．

A very rare case of non-functional pituitary adenoma associated with Rathke's cleft cyst is reported. A 42-year-old male suffering from visual disturbance and headache was admitted. Visual acuity was 1.2 on the right and 0.5 on the left,and visual field examination showed bitemporal hemianopsia. Endocrinological study disclosed that the basal serum level of prolactin was elevated slightly to 52.6 ng/ml,whereas those of other hormones were within normal limits. MRI showed a dumbbell-shaped cystic sellar mass extending to the suprasellar region beyond the diaphragm sellae,which consisted of two isolated components around the sellar turcica.

　At the middle of May,the tumor was partially removed by bifrontal craniotomy. The suprasellar tumor tightly adhered to the frontal lobe and the optic nerve,the tumor was grayish cyst and cyst fluid from the suprasellar mass had the appearance of motor oil and the intrasellar tumor contained old hematoma.

　Histological findings revealed that the suprasellar mass was Rathke's cleft cyst and the intrasellar mass was diagnosed as pituitary adenoma (non-functional). Visual acuity was improved following surgical operation.

　So far twenty-three cases of pituitary adenoma associated with Rathke's cleft cysts have been reported in the literature,but there was only one case reported of a non-functional pituitary adenoma associated with a Rathke's cleft cyst. Etiology and pathogenesis of the coexistence of non-functional pituitary adenoma and Rathke's cleft cyst in the present case were not elucidated.