[Performance of Knosp grade for cavernous sinus invasion of Cushing's disease].

To review the outcomes in patients with Cushing's disease (CD) after transsphenoidal surgery (TSS) and to assess the performance of Knosp grade for cavernous sinus invasion (CSI). Medical records were reviewed for patients with CD undergoing TSS from 1978 to 2017 at Peking Union Medical College Hospital. Based on whether CSI was observed during surgery, the sensitivity and specificity of Knosp grade for CSI were evaluated. There were 1 061 records of CD reviewed, 83 (7.82%) of which were invasive tumors evaluated by surgery, and 44 (53.0%) of these remained in endocrinological remission at the last follow-up. The sensitivity of Knosp grade for CSI was 47.0%, and the specificity was 91.1%; besides, the positive predictive value was 31.0%, and the negative predictive value was 95.3%. Initial TSS for CD with invasive adenomas is of relatively low remission rate. Knosp grade 0-2 for non-invasive tumors is reliable, while it is doubtful whether or not Knosp grade 3-4 indicates invasive tumor.