Endocrine Abstracts

Introduction: Diagnosis and exact localization of minute adenomas in Cushing disease (CD) can be problematic, leading to unsuccessful trans-sphenoidal pituitary explorations (TSS). In addition to the well established inferior petrosal sinus sampling (IPS) first described in 1989, direct intraoperative cavernous sinus sampling (CSS) and in 1993, preoperative CSS with very small catheters, have been published (1,2). The experience in relatively small series had been promising, but is rarely discussed as an alternative to IPS (3). Therefore, we present our good results with CSS in a reasonably large number of CD cases.

Methods: consecutive trans-sphenoidal surgeries (1999 to 2010) in patients with CD were included in this prospective study. All had the triad of high cortisol in night salivary cortisol, dexamethasone suppression and stimulation of ACTH and cortisol after CRH. 60 patients (15%) were referred to our neuro-radiologists for CSS according to the technique of Teramoto (2). The indications for CSS were unclear endocrine tests in 7 and inconclusive high standard magnetic resonance imaging (MRI) in all 60.

Results: In two patients (3%) CSS was technically inadequate. Since the Cushing triad was positive, TSS was performed. No central-peripheral (CP) gradient was found in 7 patients with equivocal tests. In two the ectopic source was confirmed. Thus, we cannot exclude some false negative CSS as published for IPS (4, 5). From 51 patients with a clear CP gradient, the lateralisation was correct in 41 (80%). Of 6 patients with no lateralisation in CSS, four had midline, and two had bilateral adenomas. No severe complications related to CSS were encountered.

Conclusion: With CSS non-pituitary ACTH dependent Cushing could be diagnosed in 7 patients. In 92% of cases with unclear MRI, CSS was of essential help for the accurate detection of ACTH microadenomas and seems to be superior to IPS.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector