Revalidation of inferior petrosal sinus sampling: the latest results from a single-center experience

Abstract

Cushing's disease (CD), which manifests as excess cortisol secretion, is caused by adrenocorticotrophic hormone (ACTH)-secreting pituitary adenomas. Such adenomas are occasionally difficult to identify on magnetic resonance imaging (MRI), and thorough endocrinological examination may be required to detect them. Inferior petrosal sinus (IPS) sampling (IPSS) has been the gold standard test for distinguishing CD from ectopic ACTH syndrome (EAS). However, IPSS is an invasive procedure, and proper catheterization is occasionally challenging due to anatomical variations. Thus, there have been ongoing debates regarding the necessity of this procedure. Here, we present our recent IPSS data derived from the analysis of 65 patients who were referred to us for possible CD between April 2018 and December 2020 after undergoing meticulous endocrinological testing. Even with detailed MRI, no obvious lesions were identified in 19 patients. IPSS performed on these 19 individuals identified an IPS-to-peripheral ACTH gradient in 15 of them. The four patients who lacked this gradient were subjected to a classical algorithm using concurrently measured prolactin levels, the results of which were consistent with their ultimately confirmed diagnoses: two true-positive and two true-negative diagnoses. These findings support the validity of the algorithm and demonstrate that the prolactin-adjusted IPS-to-peripheral ACTH ratio can improve the differentiation between CD and EAS. We had no false-negative results, but three patients were false-positive. Consequently, those three patients in which no apparent tumor was clarified during surgery could not have any endocrinological improvement postoperatively.

Bilateral inferior petrosal sinus sampling: Procedural data from a German single-center study

“…We found basal accuracy rates of 89 %, which could be further increased to 98 % by utilizing CRH stimulation in our cohort. Some authors advocate the use of a microcatheter for sampling owing to the potential of blocking or diverting the sinus drainage when utilizing larger catheters [21]. Although microcatheters were not used in our study, a remarkable success rate was still achieved, possibly due to the preferential use of catheters with additional side holes.…”

Successful Superficial Blood Sampling to Localize a Fibroblast Growth Factor-23-Producing Tumor

“…Inferior petrosal sinus sampling has been performed to confirm the localization of ACTH-producing tumors or investigate the source of elevated ACTH levels and whether it originated from the pituitary gland [ 7 , 21 ]. This method is especially useful for the differential diagnosis of Cushing’s disease and ec-topic ACTH syndrome and for the localization of minimum pituitary adenomas.…”