Diagnostic Value of Bilateral Petrosal Sinus Sampling in Children with Cushing Disease: A Multi-center Study

OBJECTIVE

Although the sensitivity and specificity of bilateral inferior petrosal sinus sampling (BIPSS) were shown to be quite high in adult patients, pediatric studies are limited in number and have conflicting results, since BIPSS is much less commonly performed in children. The aim of this study was to assess the role of BIPSS in the detection and accuracy of lateralization of pituitary adenomas in pediatric patients with Cushing disease (CD) and its possible advantage over other diagnostic methods.

METHODS

This was a multicenter, nationwide, web-based study. The diagnostic value of BIPSS in 16 patients, aged between four and 16.5 years with a confirmed diagnosis of CD, was evaluated retrospectively. The sensitivity and specificity of BIPSS and magnetic resonance imaging (MRI) were calculated, and compared statistically.

RESULTS

Standard tests, except for morning cortisol level, were effective in proving the presence of Cushing syndrome. While MRI findings were consistent with microadenoma in eight cases (50%), CD presence and lateralization was successfully predicted in 14 of 16 patients using BIPSS. BIPSS compared with MRI examination was significantly more accurate, both in pre-stimulation and post-stimulation results (p=0.047 and p=0.041, respectively). BIPSS showed a significantly higher sensitivity (92.8%) than MRI in detecting the pituitary source of adrenocorticotropic hormone secretion.

CONCLUSION

These results suggest that BIPSS is superior to MRI for diagnostic work-up to confirm the diagnosis of CD. Moreover, in line with previous studies, BIPSS was shown to provide better information about adenoma location, which is vital for possible surgical intervention.

Surgical outcomes and multidisciplinary management strategy of Cushing's disease: a single-center experience in China

OBJECTIVE

The primary aim of this study was to investigate the value of multidisciplinary team (MDT) management in treating patients with Cushing's disease (CD). The secondary aim was to assess the concordance of bilateral inferior petrosal sinus sampling (BIPSS) lateralization with intraoperative observations.

METHODS

The authors recruited 124 consecutive patients (128 procedures) who had undergone endoscopic endonasal resection of adrenocorticotropic hormone-secreting pituitary adenomas from May 2014 to April 2018 and assessed their clinical characteristics, surgical outcomes, and adjuvant therapies. The criteria for surgical remission were normalized serum and urinary cortisol levels, which could be suppressed by a low-dose dexamethasone suppression test at 3-months' follow-up without adjuvant treatment.

RESULTS

The remission rates of the 113 patients with long-term follow-up (20.3 ± 12.2 months) were 83.2% after surgery alone and 91.2% after adjuvant therapy. The surgical remission rates of macroadenomas, MRI-visible microadenomas, and MRI-negative tumors were 66.7% (12/18), 89.3% (67/75), and 75% (15/20), respectively (p = 0.039). The surgical remission rates had a trend of improvement during the study period (87.5% in 2017-2018 vs 76.5% in 2014, p = 0.517). Multivariate regression analysis showed that a history of previous pituitary surgery (OR 0.300, 95% CI 0.100-0.903; p = 0.032) and MRI-visible microadenoma (OR 3.048, 95% CI 1.030-9.019; p = 0.044) were independent factors influencing surgical remission. The recurrence rate was 3.2% after a mean of 18 months after surgery. The remission rate of postoperative MDT management in patients with persistent disease was higher than non-MDT management (66.7% vs 0%, p = 0.033). In cases with preoperative BIPSS lateralization, 84.6% (44/52) were concordant with intraoperative findings.

CONCLUSIONS

MRI-visible microadenoma and primary surgery were independent predictors of surgical remission in CD. The MDT management strategy helps to achieve a better overall outcome. BIPSS may help to lateralize the tumor in MRI-negative/equivocal microadenomas.

An Optimized Pathway for the Differential Diagnosis of ACTH-Dependent Cushing's Syndrome Based on Low-Dose Dexamethasone Suppression Test

CONTEXT

Traditionally, low-dose dexamethasone suppression test (LDDST) was used to confirm the diagnosis of Cushing's syndrome (CS), and high-dose dexamethasone suppression test (HDDST) was used to differentiate Cushing's disease (CD) and ectopic adrenocorticotropin (ACTH) syndrome (EAS), but some studies suggested that HDDST might be replaced by LDDST. For the differential diagnosis of CS, dexamethasone suppression test was usually combined with other tests such as bilateral petrosal sinus sampling (BIPSS) and pituitary magnetic resonance imaging, but the optimal pathway to incorporate these tests is still controversial.

OBJECTIVES

To develop an optimized pathway for the differential diagnosis of CD and EAS based on LDDST.

DESIGN AND SETTING

Single-center retrospective study (2011-2019).

PATIENTS

Two hundred sixty-nine CD and 29 EAS patients with pathological diagnosis who underwent consecutive low- and high-dose DST.

RESULTS

For the differential diagnosis of CD and EAS, the area under curve (AUC) of LDDST using urine free cortisol (0.881) was higher than that using serum cortisol (0.685) (p < 0.001) in head-to-head comparison among a subgroup of 108 CD and 10 EAS. The AUC of LDDST (0.883) was higher than that of HDDST (0.834) among all the included patients. With the cutoff of <26%, the sensitivity and specificity of LDDST were 39.4% and 100%. We designed a new pathway in which BIPSS was only reserved for those patients with unsuppressed LDDST and adenoma <6mm, yielding an overall sensitivity of 97.7% and specificity of 86.7%.

CONCLUSION

LDDST had similar value to HDDST in differentiating CD and EAS using the specific cutoff point. The pathway that combined LDDST and BIPSS could differentiate CD and EAS accurately.

The Optimal Cut-off of BIPSS in Differential Diagnosis of ACTH-dependent Cushing's Syndrome: Is Stimulation Necessary?

CONTEXTS

Bilateral inferior petrosal sinus sampling (BIPSS) can differentiate Cushing's disease (CD) and ectopic adrenocorticotropin (ACTH) syndrome (EAS). The traditional cutoff of inferior petrosal sinus to peripheral (IPS:P) ACTH gradient was 2 before stimulation and 3 after stimulation, which yielded unsatisfactory sensitivity in some studies.

OBJECTIVES

To determine the optimal cutoff in BIPSS before or after desmopressin stimulation and to evaluate the necessity of stimulation.

DESIGN AND SETTING

Single-center retrospective study (2011-2018) along with meta-analysis.

PATIENTS

226 CD and 24 EAS patients with confirmed diagnosis who underwent BIPSS with desmopressin stimulation.

RESULTS

In the meta-analysis of 25 studies with 1249 CD and 152 EAS patients, the traditional cutoff yielded sensitivity of 86% and 97% and specificity of 98% and 100% before and after stimulation, respectively. We then analyzed the data from our center. With the traditional cutoff, the sensitivity was 87.2% (197/226) and 96.5% (218/226) before and after stimulation, and specificity was both 100% (25/25), which were close to the results of meta-analysis. Receiver operating characteristic analysis revealed that the optimal cutoff was 1.4 before stimulation and 2.8 after stimulation. With the new cutoff, the sensitivity was 94.7% (214/226) and 97.8% (221/226) while the specificity remained 100% (25/25) before and after stimulation. Among the 7 CD patients (7/226; 3.1%) for whom stimulation was necessary to get correct diagnosis, none has a pituitary lesion >6 mm by magnetic resonance imaging, and their sampling lateralization rate (P = .007) and peak ACTH level at dominant inferior petrosal sinus (P = .011) were lower than those among CD patients with IPS:P >1.4 before stimulation.

CONCLUSIONS

The optimal cutoff for IPS:P in BIPSS is different from the commonly-used one. The optimal cutoff value can yield satisfactory accuracy even without stimulation, and stimulation may be unnecessary for those with pituitary adenoma >6 mm.

External jugular venous sampling for Cushing's disease in a patient with hypoplastic inferior petrosal sinuses

The authors report the case of a 30-year-old female patient with suspected Cushing's disease with an anatomical variation of hypoplastic inferior petrosal sinuses and nearly exclusive anterior drainage from the cavernous sinus, who underwent external jugular venous blood sampling with successful disease confirmation and microadenoma localization. The patient presented with signs and symptoms consistent with Cushing's syndrome, but with discordant preliminary diagnostic testing. She underwent attempted bilateral inferior petrosal sinus sampling; however, she had hypoplastic inferior petrosal sinuses bilaterally and predominantly anterior drainage from the cavernous sinus into the external jugular circulation. Given this finding, the decision was made to proceed with external jugular venous access and sampling in addition to internal jugular venous sampling. A positive adrenocorticotropic hormone (ACTH) response to corticotropin-releasing factor was obtained in the right external jugular vein alone, suggesting a right-sided pituitary microadenoma as the cause of her Cushing's disease. The patient subsequently underwent a transsphenoidal hypophysectomy that confirmed the presence of a right-sided ACTH-secreting microadenoma, which was successfully resected. She was hypocortisolemic on discharge and has had no signs of recurrence or relapse at 6 months postoperation.

A personal series of 100 children operated for Cushing's disease (CD): optimizing minimally invasive diagnosis and transnasal surgery to achieve nearly 100% remission including reoperations

Background Transnasal surgery (TNS) is the first choice in the treatment of pediatric Cushing's disease. The question is how can high remission rates be achieved with minimally invasive investigations and TNS whilst avoiding radiotherapy or bilateral adrenalectomy in children. Methods Data from a published series 1 (n=55) of surgeon DKL will be compared with his recent series 2 (n=45) until 2009. All patients were operated by direct transnasal microsurgery. Over time, inferior petrosal sinus sampling (IPSS) was replaced by cavernous sinus sampling (CSS), restricted to unclear cases without increase of salivary cortisol in corticotropin-releasing hormone-test, difficult sellar anatomy or negative magnetic resonance imaging (MRI). Multiple direct intra-operative micro-cytology, micro-doppler and adequate visualization techniques are described. Results In series 1, IPSS was performed in 13 (24%) of whom 46% had false adenoma lateralization. All adenomas could be removed with extensive pituitary exploration. Three patients had early successful re-surgery. In series 2, with more refined MRI and endocrinology, CSS was used in only seven patients (15%) and all micro-adenomas were correctly localized. In three of four patients with persistent cortisol excess, repeat-TNS was necessary and successful. Side effects of TNS were minimal. Recurrence rates were 16% and 11% in series 1 and 2, respectively. Only four of 100 children with invasive adenomas were irradiated, significantly less than in other experienced pediatric centers. Conclusions Thus, 98% remission rate could be achieved with fewer invasive pre-surgical investigations, such as central catheter studies, refined TNS and early repeat-TNS. Repeat-TNS in recurrences minimized the need for irradiation.

Tumour lateralization in Cushing's disease by inferior petrosal sinus sampling with desmopressin

BACKGROUND

Bilateral inferior petrosal sinus sampling (IPSS) with corticotropin-releasing hormone (CRH) is currently the gold standard in the diagnosis of Cushing's disease (CD) and has also been used in tumour lateralization. Our objective was to determine the diagnostic value and lateralization accuracy of IPSS with desmopressin.

METHODS

We retrospectively analysed 91 patients with Cushing's syndrome who had either negative findings on pituitary dynamic enhanced magnetic resonance imaging (MRI) or nonsuppressed high-dose dexamethasone suppression tests (HDDST). Thin-slice thoracoabdominal computed tomography (CT) and octreotide receptor imaging of whole body were also negative to rule out ectopic adrenocorticotropin hormone (ACTH) syndrome. All patients went through IPSS with desmopressin. Afterwards, transsphenoidal pituitary surgery, light microscope pathology and immunohistological staining for ACTH were performed in all patients.

RESULTS

Diagnosis of CD. Among the 91 patients included, 90 were confirmed with CD, of whom 89 had positive IPSS findings, therefore the sensitivity was 98.9%. The one patient who was negative for CD also had negative IPSS findings, therefore the specificity was 100%. Tumour lateralization. Among the 51 patients who were ultimately diagnosed with CD and whose lateralization by IPSS and surgery was either left or right, 37 had IPSS lateralization in concordance with surgery, therefore the concordance rate was 72.5%. Patients in the concordant group had a higher frequency of right lateralization by surgery.

CONCLUSIONS

IPSS with desmopressin is a sensitive approach in the diagnosis of CD and has moderate accuracy in tumour lateralization, making it an alternative choice to IPSS with CRH.

Prolactin correction for adequacy of petrosal sinus cannulation may diminish diagnostic accuracy in Cushing's disease

OBJECTIVE

Petrosal venous prolactin concentrations have been promoted to improve the diagnostic accuracy of inferior petrosal sinus sampling (IPSS), beyond that achieved with ACTH measurement alone, in diagnosing a pituitary ACTH source and determining corticotrophinoma side (L/R). Our objective was to assess the effect of using prolactin to confirm adequacy of petrosal cannulation in a cohort of patients with ACTH-dependent Cushing's syndrome.

DESIGN

Retrospective cohort study.

PATIENTS

Thirteen patients with clinical and biochemical Cushing's syndrome who underwent IPSS.

MEASUREMENTS

Serum prolactin and ACTH in peripheral and inferior petrosal sinus blood before and after corticotrophin-releasing hormone (CRH) injection.

RESULTS

Thirteen consecutive patients were diagnosed with Cushing's disease using uncorrected ACTH ratios. The side of PRL excess was the same as the side of ACTH excess in all cases. Use of various published prolactin-related equations suggested that the ACTH non-dominant side was not cannulated in four, six or seven patients depending on the equation used. The equations generally decreased the central-to-peripheral gradient on the uncorrected ACTH dominant side, increased the central-to-peripheral gradient on the contralateral side and diminished or even reversed the ACTH intersinus gradient.

CONCLUSIONS

Consistent co-lateralisation of prolactin and ACTH in IPSS strongly suggests that prolactin cannot act as an independent guide to the diagnosis and lateralisation of Cushing's disease. All patients with Cushing's disease had a prolactin intersinus gradient towards the tumourous side of the pituitary, for likely biological reasons. PRL-corrected ACTH concentrations may threaten the sensitivity and specificity of IPSS in diagnosing Cushing's disease and conceal lateralisation.

Bilateral inferior petrosal sinus sampling

Simultaneous bilateral inferior petrosal sinus sampling (BIPSS) plays a crucial role in the diagnostic work-up of Cushing's syndrome. It is the most accurate procedure in the differential diagnosis of hypercortisolism of pituitary or ectopic origin, as compared with clinical, biochemical and imaging analyses, with a sensitivity and specificity of 88-100% and 67-100%, respectively. In the setting of hypercortisolemia, ACTH levels obtained from venous drainage of the pituitary are expected to be higher than the levels of peripheral blood, thus suggesting pituitary ACTH excess as the cause of hypercortisolism. Direct stimulation of the pituitary corticotroph with corticotrophin-releasing hormone enhances the sensitivity of the procedure. The procedure must be undertaken in the presence of hypercortisolemia, which suppresses both the basal and stimulated secretory activity of normal corticotrophic cells: ACTH measured in the sinus is, therefore, the result of the secretory activity of the tumor tissue. The poor accuracy in lateralization of BIPSS (positive predictive value of 50-70%) makes interpetrosal ACTH gradient alone not sufficient for the localization of the tumor. An accurate exploration of the gland is recommended if a tumor is not found in the predicted area. Despite the fact that BIPSS is an invasive procedure, the occurrence of adverse events is extremely rare, particularly if it is performed by experienced operators in referral centres.