垂体颗粒细胞瘤影像学特征分析3例

Rare Presentation of Granular Cell Tumor sof the Neurohypophysis:Three Case Reports

目的探讨垂体颗粒细胞瘤的影像学特征,提高鉴别诊断能力。方法对3例手术病理证实的垂体颗粒细胞瘤进行回顾性分析,观察肿瘤的发病年龄、发病部位、病灶形态、密度、信号及强化特点。结合既往文献报道,分析该病的影像特征。结果3例病灶均起源于垂体柄,位于鞍内及鞍上,其中男2例,女1例,CT平扫3例均为高密度,CT值约为40~59 HU,增强扫描为明显均匀强化。MRI平扫T_1WI 3例均呈等信号,T_2WI 2例呈等信号,1例呈略低信号,增强扫描1例明显均匀强化,2例明显不均匀强化。结论垂体颗粒细胞瘤呈孤立性实性肿块,多见于中老年女性,病灶位于垂体柄,主要见于鞍上,也可同时累及鞍内和鞍上,CT上呈高密度,MRI上为等T_1、等T_2或短T_2信号,明显强化。

Objective This study aims to investigate imaging characteristics of hypophyseal Granular cell tumor（GCT）to increase the accuracy of its diagnosis.Methods A retrospective analysis was conducted for imaging of 3 cases of patients with hypophyseal Granular cell tumor confirmed by surgical pathology.The present study retrospectively analyzed the clinical data,CT findings and MRI findings of granular cell tumor,incluing age,position,shape,density,signal characteristics and enhencing characteristics.Results Three cases of lesions originated in the pituitary stalk,located both in the intra-and suprasellar location;2 cases were male,one case was female.On plain CT scan,all the three cases were hyperattenuating,and their CT values were about 40-59 HU.Enhanced CT of brain demonstrated three cases which showed homogenous enhancement.Three cases were isointense on T_1WI.Two cases were isointense on T_2WI,but the other one case was hypointense on T_2WI.One case enhanced homogenously after gadolinium administration,and the other two cases enhanced heterogeneously.Conclusion Hypophyseal GCT usually showed as a solitary,firm mass arising from the pituitary stalk.Hypophyseal GCT were mainly suprasellar and mainly occured in the adult with a female predilection.They are hyperattenuating compared with brain on non-contrast CT.GCT were mainly isointense on T_1WI,isointense or hypointense on T_2WI and showed homogeneous enhancement after gadolinium administration.