垂体病变的估计患病率在放射学研究中为10%至38.5%。然而，这些伴随病变应多频率地接受序列性垂体磁共振成像（MRI）监测的频率仍不明确。为评估垂体微腺瘤随时间的变化，进行回顾性纵向队列研究。地点位于马萨诸塞州波士顿的马萨诸塞大总医院。研究对象来自MRI中显示垂体微腺瘤的证据，对微腺瘤的大小进行了测量。在研究期间（从2003年至2021年），共识别出414例垂体微腺瘤患者。其中177名患者进行了多次MRI检查，包括78名患者微腺瘤大小未发生差异，49名患者微腺瘤大小增加，34名患者微腺瘤大小缩小，16名患者微腺瘤大小发生变化。通过线性混合模型分析，估计坡度为0.016 mm/y（95% CI，-0.037至0.069）。在分组分析中，基线尺寸小于4 mm的垂体腺瘤倾向于增大。估计坡度为0.09mm/y（CI，0.020至0.161）。相比之下，在基线肿瘤大小大于4 mm的亚组中，大小倾向于缩小。估计坡度为-0.063mm/y（CI，-0.141至0.015）。回顾性队列研究，有些患者由于未知原因未能进行随访，数据仅限于本地大型机构。在研究期间，约三分之二的微腺瘤大小保持不变或缩小。如有增长，则增长缓慢。这些发现表明，对于随机发现垂体微腺瘤的患者，较少的垂体MRI监测可能是安全的。没有任何资助。

The estimated prevalence of pituitary lesions is 10% to 38.5% in radiologic studies. However, how frequently these incidental lesions should be monitored by serial pituitary magnetic resonance imaging (MRI) remains unclear.To evaluate changes in pituitary microadenomas over time.Retrospective, longitudinal cohort study.Mass General Brigham, Boston, Massachusetts.Evidence of pituitary microadenoma from MRI.Dimensions of pituitary microadenomas.During the study period (from 2003 to 2021), 414 patients with pituitary microadenomas were identified. Of the 177 patients who had more than 1 MRI, 78 had no change in the size of the microadenoma over time, 49 had an increase in size, 34 had a decrease in size, and 16 had both an increase and decrease in size. By linear mixed model analysis, the estimated slope was 0.016 mm/y (95% CI, -0.037 to 0.069). In the subgroup analysis, pituitary adenomas with a baseline size of 4 mm or less tended to increase in size. The estimated slope was 0.09 mm/y (CI, 0.020 to 0.161). In contrast, in the subgroup with baseline tumor size greater than 4 mm, the size tended to decrease. The estimated slope was -0.063 mm/y (CI, -0.141 to 0.015).Retrospective cohort, some patients were lost to follow-up for unknown reasons, and data were limited to local large institutions.During the study period, approximately two thirds of the microadenomas remained unchanged or decreased in size. The growth, if any, was slow. These findings suggest that less frequent pituitary MRI surveillance for patients with incidental pituitary microadenomas may be safe.None.