Improved Diagnostic Accuracy of Inferior Petrosal Sinus Sampling over Imaging for Localizing Pituitary Pathology in Patients with Cushing's Disease
The majority of patients with Cushing's disease can be cured by transsphenoidal microsurgery; however, precise localization of the pituitary source of ACTH is not always possible by standard imaging techniques. Bilateral venous sampling from the inferior petrosal si- nuses (IPSS) is also useful for diagnosing Cushing's disease, but the interpretation of discordant findings between IPSS and imaging re- mains problematic. We tested the ability of imaging and IPSS to localize an ACTH-secreting pituitary lesion in comparison to defin- itive histopathological examination of the pituitary in patients with Cushing's disease (n 5 37). Bilateral IPS catheterization was tech- nically feasible in 32 patients and provided evidence of lateralization in 31 patients. Histological examination confirmed a corticotropic adenoma in 28 patients and corticotropic hyperplasia in 2 patients; Crooke's hyaline change was found in 7 patients, among whom 1 subsequently was found to have an ectopic sphenoid corticotropic adenoma, and the remainder had suspected microadenomas that were not identified microscopically. Accurate localization of the pi- tuitary lesion was more frequent when based on IPSS results than on imaging studies (70% vs. 49%, P , 0.06). The 2 tests provided directly discrepant results for 8 patients; among these, IPSS was more likely than imaging to agree with final pathology (63% vs. 13%, P , 0.10). Imaging was entirely normal for another 9 patients, in whom IPSS accurately localized the lesion for the majority (89%; 95% confidence interval: 50 -99%). We suggest that IPSS is an effective tool for lo- calizing pituitary pathology and planning surgery for patients with Cushing's disease. (J Clin Endocrinol Metab 83: 2291-2295, 1998)
Published in 2010.