Cavernous sinus sampling in patients with Cushing's disease

Bilateral inferior petrosal sinus sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome: A reappraisal

Cushing's syndrome (CS) is a rare disorder, once exogenous causes have been excluded. However, when diagnosed, the majority of cases are adrenocorticotropic hormone (ACTH)-dependent, of which a substantial minority are due to a source outside of the pituitary, ectopic ACTH syndrome (EAS). Differentiating among pituitary-dependent CS, Cushing's disease (CD) and an ectopic source can be problematic. Because non-invasive tests in the evaluation of CS patients often lack adequate sensitivity and specificity, bilateral inferior petrosal sinus sampling (BIPSS), a minimally invasive procedure performed during the investigation of ACTH-dependent CS, can be extremely helpful. BIPSS is considered to be the gold standard for differentiating CD from the EAS. Furthermore, although such differentiation may indeed be challenging, BIPSS is itself a complex investigation, especially in recent times due to the widespread withdrawal of corticotrophin-releasing hormone and its replacement by desmopressin. We review current published data on this investigation and, in the light of this and our own experience, discuss its appropriate use in diagnostic algorithms.

Double pituitary adenomas: report of two cases and systematic review of the literature

Objective

Double pituitary adenomas (DPA) are a rare clinical condition, and our knowledge of them is limited. Missing the second lesion leading to incomplete biochemical remission after surgery is an important challenge in DPA management. This study aims to analyze independent prognostic factors in DPA patients and summarize clinical experiences to prevent surgical failure.

Methods

Two cases of DPA patients with Cushing's disease diagnosed and surgically treated at Peking Union Medical College Hospital are reported. A literature review was performed on the online database Pubmed, and 57 DPA patients from 22 retrieved articles were included. Demographic characteristics, endocrine manifestations, diagnostic methods, tumor size, and immunohistochemical features of 59 patients were analyzed. Binary logistic regression models were used to identify independent prognostic factors affecting postoperative biochemical remission.

Results

Among 59 DPA patients, the mean ± SD age was 43.64 ± 14.42 years, with 61.02% being female (n = 36). The most common endocrine manifestations were Cushing's syndrome (23/59, 38.98%) and acromegaly (20/59, 33.90%). The most prevalent immunohistochemical types were ACTH-immunopositive (31/118, 26.27%) and GH-immunopositive (31/118, 26.27%) tumors. Microadenomas (<1cm) were the most frequent in terms of tumor size (62/92, 67.39%). The detection rate for double lesions on 3.0T MRI was 50.00% (14/28), which significantly higher than 1.5T MRI (P = 0.034). Univariate analysis revealed that female, Cushing's syndrome and only single lesion detected by surgical exploration were associated with significantly worse prognosis (P<0.05). Multivariate analysis identified double lesion detected by surgical exploration (OR = 0.08, P = 0.003) and contiguous type tumor (OR = 0.06, P = 0.017) as independent protective factors for DPA patients.

Conclusions

The double lesion detected by surgical exploration is independently associated with a better prognosis for DPA patients. Comprehensive intraoperative exploration are crucial measures to avoid missing causative lesions.

Diagnostic workup of Cushing's syndrome

Cushing's syndrome (CS) is a rare but detrimental endocrine disorder. Early diagnosis and prompt treatment are essential since the duration of hypercortisolism has an adverse impact on the extent of comorbidities and overall survival. The diagnostic approach involves a stepwise process that includes (1) screening and confirming the diagnosis and (2) establishing the aetiology of CS. The tests currently used to confirm the diagnosis of CS include urinary free cortisol measurements, the dexamethasone suppression test and late- night salivary cortisol or midnight serum cortisol measurements. None of these tests are ideal; all have pitfalls and require careful interpretation. Following confirmation of CS, measurement of ACTH discriminates between ACTH-dependent and non-ACTH dependent causes of CS. Adrenal imaging provides clues for the aetiology of non-ACTH dependent forms. Differentiation between the ACTH-dependent forms that involve pituitary corticotroph adenomas and ectopic ACTH sources is more complex and include pituitary MRI imaging, the high dose dexamethasone suppression test, the CRH test, bilateral inferior petrosal sinus sampling and, when required imaging modalities to detect ectopic ACTH secreting lesions. This review, which is part of a special issue on "Update of Cushing's syndrome: 100 years after Minnie G" will provide an update on our current diagnostic workup for the confirmation and differential diagnosis of CS.

Does concomitant prolactin measurement ıncrease the accuracy of ınferior petrosal sinus sampling?

INTRODUCTION

Prolactin (PRL) measurement during inferior petrosal sinus sampling (IPSS) can be helpful to improve the accuracy. We aimed to evaluate the effect of measuring PRL levels as a predictor for the accuracy of IPSS and evaluate its impact on the lateralization of adenomas.

METHODS

In this retrospective cohort study, we reviewed 51 patients who had undergone IPSS for the investigation of ACTH-dependent hypercortisolism.

RESULTS

Forty-nine patients had proven Cushing's disease (CD), one had EAS, and the remaining one patient had adrenal adenoma. Forty-seven patients had an above 2 ACTH IPS/P ratio at baseline, and all the post-corticotropin-releasing hormone (CRH) ACTH IPS/P ratios of patients with proven CD were above 3. In these two patients whose ACTH IPS/P ratio at baseline was below 2, PRL IPS/P ratios were above 1.8 in only the dominant side, which was considered secondary to a prolactin intersinus gradient due to the biological effects of the tumor. PRL-adjusted ACTH IPS/P ratios were > 1.3 in all patients with proven CD; it was 0.7 in the patient with EAS. Surgically confirmed positive lateralization was observed in 55.1% of patients with the ACTH gradient, but when PRL-adjusted ACTH IPS/IPS ratios were used in addition to the ACTH gradient, the ratio increased to 67.3%.

CONCLUSION

Although PRL-adjusted ACTH IPS/P ratios can be helpful to improve the accuracy of results during IPSS procedures, a prolactin intersinus gradient towards the ACTH-dominant side in patients with CD may invalidate PRL as an indicator of pituitary venous outflow.

Pitfalls in Performing and Interpreting Inferior Petrosal Sinus Sampling: Personal Experience and Literature Review

CONTEXT

Inferior petrosal sinus sampling (IPSS) helps differentiate the source of ACTH-dependent hypercortisolism in patients with inconclusive biochemical testing and imaging, and is considered the gold standard for distinguishing Cushing disease (CD) from ectopic ACTH syndrome. We present a comprehensive approach to interpreting IPSS results by examining several real cases.

EVIDENCE ACQUISITION

We performed a comprehensive review of the IPSS literature using PubMed since IPSS was first described in 1977.

EVIDENCE SYNTHESIS

IPSS cannot be used to confirm the diagnosis of ACTH-dependent Cushing syndrome (CS). It is essential to establish ACTH-dependent hypercortisolism before the procedure. IPSS must be performed by an experienced interventional or neuroradiologist because successful sinus cannulation relies on operator experience. In patients with suspected cyclical CS, it is important to demonstrate the presence of hypercortisolism before IPSS. Concurrent measurement of IPS prolactin levels is useful to confirm adequate IPS venous efflux. This is essential in patients who lack an IPS-to-peripheral (IPS:P) ACTH gradient, suggesting an ectopic source. The prolactin-adjusted IPS:P ACTH ratio can improve differentiation between CD and ectopic ACTH syndrome when there is a lack of proper IPS venous efflux. In patients who have unilateral successful IPS cannulation, a contralateral source cannot be excluded. The value of the intersinus ACTH ratio to predict tumor lateralization may be improved using a prolactin-adjusted ACTH ratio, but this requires further evaluation.

CONCLUSION

A stepwise approach in performing and interpreting IPSS will provide clinicians with the best information from this important but delicate procedure.

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.

Cushing's Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

Neurosurgical treatment of Cushing disease in pediatric patients: case series and review of literature

AIM

Pituitary adenomas are rare in childhood in contrast with adults. Adrenocorticotropic hormone (ACTH)-secreting adenomas account for Cushing's disease (CD) which is the most common form of ACTH-dependent Cushing's syndrome (CS). Treatment strategies are generally based on data of adult CD patients, although some difficulties and differences exist in pediatric patients. The aim of this study is to share our experience of 10 children and adolescents with CD.

PATIENTS AND METHOD

Medical records, images, and operative notes of 10 consecutive children and adolescents who underwent transsphenoidal surgery for CD between 1999 and 2014 in Cerrahpasa Faculty of Medicine were retrospectively reviewed. Mean age at operation was 14.8 ± 4.2 years (range 5-18). The mean length of symptoms was 24.2 months. The mean follow-up period was 11 years (range 4 to 19 years).

RESULTS

Mean preoperative cortisol level was 23.435 μg/dl (range 8.81-59.8 μg/dl). Mean preoperative ACTH level was 57.358 μg/dl (range 28.9-139.9 μg/dl). MR images localized microadenoma in three patients (30%), macroadenoma in four patients (40%) in our series. Transsphenoidal microsurgery and endoscopic transsphenoidal surgery were performed in 8 and 2 patients respectively. Remission was provided in 8 patients (80%). Five patients (50%) met remission criteria after initial operations. Three patients (30%) underwent additional operations to meet remission criteria.

CONCLUSION

Transsphenoidal surgery remains the mainstay therapy for CD in pediatric patients as well as adults. It is an effective treatment option with low rate of complications. Both endoscopic and microscopic approaches provide safe access to sella and satisfactory surgical results.

Diagnostic accuracy of Bilateral Inferior Petrosal Sinus Sampling: The Experience of a Tertiary Centre

Purpose To assess the accuracy of bilateral inferior petrosal sinus sampling both in the differential diagnosis of adrenocorticotrophic hormone dependent Cushing’s syndrome and predicting the localization on the pituitary.

Methods The authors evaluated all patients that undergone bilateral inferior petrosal sinus sampling in a tertiary centre, between January 1995 and March 2018. The probable diagnosis of Cushing’s disease was made when the basal central/peripheral gradient was>2 and/or>3 after stimulation with corticotrophin releasing hormone. The localization was suggested when the inter-sinus gradient was>1.4. The results obtained were compared with the post operatory results: compatible histology and positive immunohistochemistry to adrenocorticotrophic hormone and/or the presence of criteria of cure. Sensitivity, specificity and predictive positive value were calculated.

Results A total of 49 patients were evaluated (75.5% female; mean age 45.4±16.3 years old). Bilateral inferior petrosal sinus sampling was compatible with Cushing’s disease in 27 out of 28 confirmed cases in histology or by criteria of cure, and was compatible with ectopic secretion in the 2 cases confirmed as ectopic secretion of adrenocorticotrophic hormone (sensitivity 96.4%; specificity 100%). The lateralization calculated was concordant with the results after surgery in 17 out of 27 patients with Cushing’s disease – predictive positive value of 63%. Magnetic resonance had a higher predictive value to lateralization – 70.0%.

Conclusions Bilateral inferior petrosal sinus sampling is a safe and reliable procedure to diagnose Cushing’s disease, with great sensitivity and specificity. Nevertheless, the capacity of this procedure to lateralize the lesion inside the pituitary is limited.

Influence of inferior petrosal sinus drainage symmetry on detection of adenomas in Cushing's syndrome

BACKGROUND

Asymmetric inferior petrosal sinuses (IPS) are not infrequently encountered during bilateral IPS sampling. There is little data on whether IPS symmetry influences success in predicting the adenoma side in patients with ACTH-dependent Cushing's syndrome (CS).

OBJECTIVE

To assess the influence of IPS drainage patterns on detection of an adenoma in CS.

METHODS

Retrospective single-center cohort analysis reviewing records of patients with CS and negative MRI findings who subsequently underwent BIPSS.

RESULTS

BIPSS was performed in 38 patients with a mean age of 45±15 years. The overall technical success rate was 97% for bilateral cannulation. Asymmetric IPS were observed in 11 (39%) patients with Cushing's disease (CD). A side-to-side ACTH ratio was not significantly different between patients with symmetric outflow and those with asymmetric outflow at baseline (8.6±2.7 versus 16.4±6.0; P=0.45), but ratios were significantly different after ovine corticotropin-releasing hormone (oCRH) stimulation (6.0±2.5 versus 35.7±22.5; P=0.03). BIPSS correctly predicted the side of the adenoma in 25 (96%) patients with CD. Prediction was better when the venous outflow was symmetric (100%) rather than asymmetric (93%), although the difference was not significant (P=0.42). Remission from CS was achieved in 32 patients (87%), independent of the symmetry of IPS.

CONCLUSIONS

Bearing in mind the sample size of this audit, asymmetric IPS at least do not seem to diminish the accuracy of diagnosis of ACTH-dependent CS, nor do they influence the clinical outcome.

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.

Pituitary Imaging

Modern pituitary imaging is MRI. However, computed tomography (CT) still has limited usefulness. In addition, because CT offers much better bone detail and calcium detection, there are some cases in which such additional information is necessary. Before the advent of CT, plain radiography, pneumoencephalography, and angiography were used to diagnose pituitary masses. More recently, CT, and then especially MRI, made it possible to primarily delineate lesions within and around the pituitary gland rather than depend on secondary information that could only suggest their presence.

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.

Surgical management of adrenocorticotropic hormone-secreting pituitary adenomas

Cushing's disease is defined as hypercortisolemia caused by secretion of adrenocorticotropic hormone from a pituitary adenoma. The diagnosis of Cushing's disease is based on clinical symptoms, laboratory and imaging findings. Once an adrenocorticotropic-hormone-secreting adenoma is found, the standard of care is transsphenoidal adenomectomy. MRI negative microadenomas and large, invasive macroadenomas provide a surgical and clinical challenge and are best handled at high volume centers. Multiple options exist for refractory disease or recurrence, including repeat surgery, radiosurgery and radiotherapy, medical management and bilateral adrenalectomy.

Hippocampal and cerebellar atrophy in patients with Cushing’s disease

OBJECT

Cushing’s disease (CD) may cause atrophy of different regions of the human brain, mostly affecting the hippocampus and the cerebellum. This study evaluates the use of 3-T MRI of newly diagnosed patients with CD to detect atrophic degeneration with voxel-based volumetry.

METHODS

Subjects with newly diagnosed, untreated CD were included and underwent 3-T MRI. Images were analyzed using a voxelwise statistical test to detect reduction of brain parenchyma. In addition, an atlas-based volumetric study for regions likely to be affected by CD was performed.

RESULTS

Nineteen patients with a mean disease duration of 24 months were included. Tumor markers included adre-nocorticotropic hormone (median 17.5 pmol/L), cortisol (949.4 nmol/L), and dehydroepiandrosterone sulfate (5.4 μmol/L). The following values are expressed as the mean ± SD. The voxelwise statistical test revealed clusters of significantly reduced gray matter in the hippocampus and cerebellum, with volumes of 2.90 ± 0.26 ml (right hippocampus), 2.89 ± 0.28 ml (left hippocampus), 41.95 ± 4.67 ml (right cerebellar hemisphere), and 42.11 ± 4.59 ml (left cerebellar hemisphere). Healthy control volunteers showed volumes of 3.22 ± 0.25 ml for the right hippocampus, 3.23 ± 0.25 ml for the left hippocampus, 50.87 ± 4.23 ml for the right cerebellar hemisphere, and 50.42 ± 3.97 ml for the left cerebellar hemisphere.

CONCLUSIONS

Patients with untreated CD show significant reduction of gray matter in the cerebellum and hippocampus. These changes can be analyzed and objectified with the quantitative voxel-based method described in this study.