腦下腺垂體瘤是顱內常見之良性腫瘤，也是易被FDG正子斷層造影偵知的腫瘤之一。在本院使用Siemens HR plus PET scann 造影的 1,166 人次中 (90年2月20日至91年2月25日截止於GE PET/CT Scanner 之前共計有1,140受檢者)，其中有三例在非符初衷的情況下發現有顱底蝶鞍部之強烈葡萄糖代謝攝取，進一步診斷為非分泌性巨腺瘤。此病在本研究的不分年齡層之發生率為0.26%，與國外用CT偵測之流行率相近似。此三例其後呈現之臨床表現並不一致，端視引發之症狀而作適時處置。此類腫瘤可視為意外發現之瘤，它的臨床途徑較緩和，多為良性腫瘤。當發現時，宜做基本內分泌功能檢查及基本造影，予以定時追蹤。開刀治療之決定瑞視腫瘤大小及引發相關症狀而定。本三例病吏可代表腦下腺垂體瘤主要的臨床行徑。

　　　　　Intense 18F-fiuorodeoxyglucose (FDG) uptake in the suprasellar region is suggestive of pituitary adenoma by its relative high prevalence. Three cases of pituitary macroadenoma were identified in consecutive 1,166 studies of FDG-PET from non-selective 1,140 examinees (subtract repeat scans, and exclude scans for heart only). The prevalence in this mixed-age popula-tion is 0.26%. Subsequent workup revealed nonfunc-tioning macroadenoma ranging in size from 1.5 cm to 3.3 cm, and at least one case behaves aggressively by its repeat recurrence. The therapeutic options are not standardized, one went for transphenoid hypophysectomy, another one is in conservative approach due to other more debilitating disease, and the recurrence case is pending for gamma knife treatment option after recent operation to relieve the optical symptoms. Therefore, the clinical importance is determined mainly by the size in anatomic image for local invasion potenrials, evaluating the functional status and to rule out jeopardy from other much rare malignancy. Clinical approach may be based on incidentaloma that may usually follow a benign course, and baseline evaluation and observation over time can be the initial steps.