Pure Intrasellar Meningioma Located Under the Pituitary Gland: Case Report
A 57-year-old woman was admitted to our hospital with recent memory disturbance. A magnetic resonance imaging study was performed to evaluate possible vascular dementia.\nThe imaging revealed an intrasellar mass measuring approximately 1.8 × 1.7 cm with a slightly upward bulge, homogenous isointense signals on T1- and T2-weighted images, and a focal inhomogenous signal on T2-weighted images (). On contrast-enhanced T1-weighted images, the lower portion of the sellar mass was greatly enhanced, and the upper portion, lesser enhanced (). Initially the upper portion was thought to be a pituitary adenoma and the lower portion, normal pituitary gland.\nWhen an endonasal transsphenoidal operation was performed to remove the tumor, a bulging tumor on the sellar floor was observed through the operating window. It appeared as a well-demarcated, friable, yellowish, hard mass. The normal pituitary gland was elevated and shifted to the left anterolateral side by the mass. After the tumor was removed, the diaphragma sellae was identified at the top of the sellar turcica. On histological examination, the low-lying intrasellar lesion was confirmed as a meningioma, while above it was the normal pituitary gland ().