BIPSS Diagnostic Method May Cause False Positive in Some Cases of Cyclic Cushing’s Syndrome

A diagnostic technique called bilateral inferior petrosal sinus sampling (BIPSS), which measures the levels of the adrenocorticotropic hormone (ACTH) produced by the pituitary gland, should only be used to diagnose cyclic Cushing’s syndrome patients during periods of cortisol excess, a case report shows.

When it is used during a spontaneous remission period of cycling Cushing’s syndrome, this kind of sampling can lead to false results, the researchers found.

The study, “A pitfall of bilateral inferior petrosal sinus sampling in cyclic Cushing’s syndrome,” was published in BMC Endocrine Disorders.

Cushing’s syndrome is caused by abnormally high levels of the hormone cortisol. This is most often the result of a tumor on the pituitary gland that produces too much ACTH, which tells the adrenal glands to increase cortisol secretion.

However, the disease may also occur due to adrenal tumors or tumors elsewhere in the body that also produce excess ACTH — referred to as ectopic Cushing’s syndrome.

Because treatment strategies differ, doctors need to determine the root cause of the condition before deciding which treatment to choose.

BIPSS can be useful in this regard. It is considered a gold standard diagnostic tool to determine whether ACTH is being produced and released by the pituitary gland or by an ectopic tumor.

However, in people with cycling Cushing’s syndrome, this technique might not be foolproof.

Researchers reported the case of a 43-year-old woman who had rapidly cycling Cushing’s syndrome, meaning she had periods of excess cortisol with Cushing’s syndrome symptoms — low potassium, high blood pressure, and weight gain — followed by normal cortisol levels where symptoms resolved spontaneously.

In general, the length of each period can vary anywhere from a few hours to several months; in the case of this woman, they alternated relatively rapidly — over the course of weeks.

After conducting a series of blood tests and physical exams, researchers suspected of Cushing’s syndrome caused by an ACTH-producing tumor.

The patient eventually was diagnosed with ectopic Cushing’s disease, but a BIPSS sampling performed during a spontaneous remission period led to an initial false diagnosis of pituitary Cushing’s. As a result, the woman underwent an unnecessary exploratory pituitary surgery that revealed no tumor on the pituitary.

Additional imaging studies then identified a few metastatic lesions, some of which were removed surgically, as the likely source of ACTH. However, the primary tumor still hasn’t been definitively identified. At the time of publication, the patient was still being treated for Cushing’s-related symptoms and receiving chemotherapy.

There is still a question of why the initial BIPSS result was a false positive. The researchers think that the likely explanation is that BIPSS was performed during an “off phase,” when cortisol levels were comparatively low. In fact, a later BIPSS performed during a period of high cortisol levels showed no evidence of ACTH excess in the pituitary.

This case “demonstrates the importance of performing diagnostic tests only during the phases of active cortisol secretion, as soon as first symptoms appear,” the researchers concluded.

From https://cushingsdiseasenews.com/2020/01/02/cushings-syndrome-case-study-shows-drawback-in-bipss-method/

Metabolomic Biomarkers in Urine of Cushing’s Syndrome Patients

Int. J. Mol. Sci. 2017, 18(2), 294; doi:10.3390/ijms18020294 (registering DOI)
Department of Food Sciences, Faculty of Pharmacy, Medical University of Gdańsk, Al. Gen. J. Hallera 107, 80-416 Gdańsk, Poland
Laboratory of Environmental Chemometrics, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
Department of Endocrinology and Internal Medicine, Medical University of Gdańsk, ul. Dębinki 7, 80-211 Gdańsk, Poland
Department ofEnvironmental Analytics, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
Author to whom correspondence should be addressed.
Academic Editor: Ting-Li (Morgan) Han
Received: 5 December 2016 / Revised: 9 January 2017 / Accepted: 19 January 2017 / Published: 29 January 2017
(This article belongs to the Section Molecular Diagnostics)
Download PDF [1853 KB, uploaded 29 January 2017]

Abstract

Cushing’s syndrome (CS) is a disease which results from excessive levels of cortisol in the human body. The disorder is associated with various signs and symptoms which are also common for the general population not suffering from compound hypersecretion. Thus, more sensitive and selective methods are required for the diagnosis of CS.

This follow-up study was conducted to determine which steroid metabolites could serve as potential indicators of CS and possible subclinical hypercortisolism in patients diagnosed with so called non-functioning adrenal incidentalomas (AIs).

Urine samples from negative controls (n = 37), patients with CS characterized by hypercortisolism and excluding iatrogenic CS (n = 16), and patients with non-functioning AIs with possible subclinical Cushing’s syndrome (n = 25) were analyzed using gas chromatography-mass spectrometry (GC/MS) and gas chromatograph equipped with flame ionization detector (GC/FID). Statistical and multivariate methods were applied to investigate the profile differences between examined individuals. The analyses revealed hormonal differences between patients with CS and the rest of examined individuals.

The concentrations of selected metabolites of cortisol, androgens, and pregnenetriol were elevated whereas the levels of tetrahydrocortisone were decreased for CS when opposed to the rest of the study population. Moreover, after analysis of potential confounding factors, it was also possible to distinguish six steroid hormones which discriminated CS patients from other study subjects.

The obtained discriminant functions enabled classification of CS patients and AI group characterized by mild hypersecretion of cortisol metabolites. It can be concluded that steroid hormones selected by applying urinary profiling may serve the role of potential biomarkers of CS and can aid in its early diagnosis.

 

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Supplementary material

From http://www.mdpi.com/1422-0067/18/2/294

Froedtert and MCW researchers investigate Cushing syndrome incidence in bariatric surgery patients

Researchers at the Medical College of Wisconsin determined that Cushing syndrome, an endocrine disorder, may be the potential cause for weight gain and metabolic complications for patients who have undergone bariatric surgery for obesity. The study, published in the journal Obesity Surgery, was conducted by Ty B. Carroll, MD, assistant professor of endocrinology; James W. Findling, MD, FACP, professor of endocrinology ; and Bradley R. Javorsky, MD, assistant professor of endocrinology. The physicians practice at Froedtert Hospital in Wauwatosa and Community Memorial Hospital in Menomonee Falls.

Cushing syndrome can occur when the human body is exposed to high levels of cortisol for an extended period of time. Cortisol is a hormone in the body which affects blood pressure regulation and cardiovascular system functions. Cortisol also helps regulate the body’s conversion of proteins, carbohydrates and fats from diet into usable energy. However, when the level of cortisol becomes too high, Cushing syndrome can develop.

Cushing syndrome is associated with a variety of symptoms including weight gain and fatty tissue deposits in the body. According to the American Association of Neurological Surgeons, 10 to 15 million people are affected each year by Cushing syndrome.

Bariatric surgery is a procedure performed to help with extreme cases of obesity. Weight loss is achieved by reducing the size of the stomach with a gastric band, removal of a portion of the stomach or resecting and rerouting the small intestine to a small stomach pouch. Bariatric surgery is often used as an option for individuals unable to lose weight through diet and exercise, or have serious health problems caused by obesity.

According to the American Society for Metabolic and Bariatric Surgery, 179,000 bariatric surgeries were performed in the U.S. in 2013. However, despite successes in normal weight loss cases, bariatric surgery does not provide long term weight loss for individuals diagnosed with Cushing syndrome. Cushing syndrome often goes undiagnosed as a potential cause for weight gain and metabolic complications until after the surgery is performed.

MCW researchers in this study analyzed the incidence of Cushing syndrome in patients who underwent bariatric surgery for weight loss. During the investigation, the researchers performed a retrospective chart review on a series of 16 patients diagnosed with Cushing syndrome from five tertiary care centers in the U.S. who underwent bariatric surgery. The results from the study found 12 of the analyzed patients were not diagnosed with Cushing syndrome prior to their bariatric surgery. The remaining four patients had Cushing syndrome surgery prior to bariatric surgery, without recognition that their Cushing syndrome was persistent until after the weight loss surgery. The findings from the research indicate that Cushing syndrome may be often overlooked in patients undergoing bariatric surgery.

According to the researchers, testing for Cushing syndrome should be performed prior to bariatric surgery in patients with persistent hypertension, diabetes mellitus or excessive weight regain.

From http://www.lakecountrynow.com/usersubmittedstories/366480371.html

Imaging Technique Measures Tumor Stiffness to Aid Surgical Planning

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Important steps in planning tumor surgery include identifying borders between tumor and healthy tissue and assessing the tumor stiffness, e.g. hard and calcified or soft and pliant. For decades, tumors near the surface of the body have been evaluated for stiffness by simple palpation—the physician pressing on the tissue. Because tumors within the skull cannot be palpated, researchers used Magnetic Resonance Elastography (MRE) to assess pituitary tumor stiffness by measuring waves transmitted through the skull into pituitary macroadenomas (PMAs). MRE reliably identified tumors that were soft enough for removal with a minimally-invasive suction technique versus harder tumors requiring more invasive surgery.

“The group developed brain MRE several years ago and is now successfully applying it to clinical diagnosis and treatment,” explained Guoying Liu, Ph.D., Director of the NIBIB Program in Magnetic Resonance Imaging. “This development of a new imaging technique followed by its practical application in surgical planning for better patient outcomes is an outstanding example of one of the main objectives of NIBIB-funded research.”

MRE is a special magnetic resonance imaging technique that captures snapshots of shear waves that move through the tissue and create elastograms—images that show tissue stiffness. John Huston III, M.D., Professor of Radiology at the Mayo Clinic in Rochester, MN, and senior author of the study, explains how MRE works. “MRE is similar to a drop of water hitting a still pond to create the ripples that move out in all directions. We generate tiny, harmless ripples, or shear waves, that travel through the brain of the patient. Our instruments measure how the ripples change as they move through the brain and those changes give us an extremely accurate measure–and a color-coded picture–of the stiffness of the tissue.”

MRE data enables non-invasive surgical planning

Ninety percent of PMAs are soft—nearly the consistency of toothpaste. Therefore, without MRE, surgeons would routinely plan for a procedure called transphenoidal resection that employs very thin instruments that are threaded through the nasal cavity to the pituitary gland at the base of the skull, where suction is used to remove the tumor. However, in about 10% of the cases, the surgeon will encounter a hard tumor. At that point an attempt is made to break-up the tumor—essentially chipping away at it with sharp instruments. If that is not successful, the surgeon must perform a fully-invasive craniotomy that involves removing a piece of the skull bone in order to fully expose the tumor.

The more extensive procedure means added risk and discomfort for patients, and up to a week-long recovery in the hospital compared to the transphenoidal approach that allows patients to leave the hospital in a day or two. Using MRE, hard PMAs can be identified and the more extensive craniotomy can be planned before starting the surgery, which makes the more invasive procedure less taxing for both the surgeon and patient. Similarly, MRE showing a soft PMA gives surgeons confidence that the nasal entry and removal by suction will be successful-eliminating the likelihood that the surgeon may need to perform a second fully-invasive craniotomy.

In the study of PMA reported in the January 2016 issue of the journal Pituitary, the group performed pre-surgical MRE evaluation of the PMAs of 10 patients.The MRE measurements were compared to tumor classifications made by inspection of the tumor during surgery. The surgeons categorized six tumors as soft and four tumors as medium. No tumors were deemed to be hard. The comparison of the MRE results and reports of stiffness by the surgeons when the tumor was removed and inspected were in close agreement, which was confirmed by statistical analysis.

Future plans

Although brain MRE is not yet widely available, Huston explained that the surgeons at the Mayo Clinic are now routinely using MRE to plan the best procedure for the removal of PMAs as well as several other types of brain tumor. And, even though this study of the 10 PMA patients is a very small set, Huston believes that as Mayo surgeons continue to use MRE in planning, the technique will likely begin to be adopted by other surgical centers.

Huston explained that an important aspect of some of the other brain tumor types, which the surgeons are finding extremely useful, is the ability of MRE to identify tumor adhesion to the brain. Adhesion refers to whether the brain tumor and healthy brain tissue are connected by an extensive network of blood vessels and connective tissue. This is in comparison with a tumor that is in the brain but is isolated from healthy tissue.

When MRE is used to analyze this aspect of the tumor, it clearly identifies those that are non-adhered, showing a border around the tumor through which there are no vascular connections. Conversely, MRE of adhered tumors show no border between the tumor and healthy brain, indicating extensive vascular and soft tissue connections between brain and tumor. Mutual blood vessels make removal of adherent tumors much more difficult, with a much higher chance of damage to healthy tissue and potential loss of function for the patient.

Huston and his colleagues are continuing to apply MRE, often called “palpating by imaging” to diagnosis of other brain disorders. In addition to characterizing focal brain disorders such as tumors, the group is testing the potential for MRE to provide diagnostic information about diffuse brain disease, and are currently using MRE brain stiffness patterns to identify different types of neural disorders including dementia.

This research was funded by the National Institutes of Health through the National Institute of Biomedical Imaging and Bioengineering grant EB001981.

Magnetic resonance elastography detects tumoral consistency in pituitary macroadenomas. Hughes JD, Fattahi N, Van Gompel J, Arani A, Ehman R, Huston J 3rd. Pituitary. 2016 Jun;19(3):286-92

From http://www.rdmag.com/news/2017/01/imaging-technique-measures-tumor-stiffness-aid-surgical-planning

Identification Of Potential Markers For Cushing’s Disease

Endocr Pract. 2016 Jan 20. [Epub ahead of print]

Abstract

OBJECTIVE:

Cushing’s disease (CD) causes a wide variety of nonspecific symptoms, which may result in delayed diagnosis. It may be possible to uncover unusual combinations of otherwise common symptoms using ICD-9-CM codes. Our aim was to identify and evaluate dyads of clinical symptoms or conditions associated with CD.

METHODS:

We conducted a matched case-control study using a commercial healthcare insurance claims database, designed to compare the relative risk (RR) of individual conditions and dyad combinations of conditions among patients with CD versus matched non-CD controls.

RESULTS:

With expert endocrinologist input, we isolated 10 key conditions (localized adiposity, hirsutism, facial plethora, polycystic ovary syndrome, abnormal weight gain, hypokalemia, deep venous thrombosis, muscle weakness, female balding, osteoporosis) with RR varying from 5.1 for osteoporosis to 27.8 for hirsutism. The RR of dyads of these conditions ranged from 4.1 for psychiatric disorders/serious infections to 128.0 for hirsutism/fatigue in patients with vs. without CD. Construction of uncommon dyads resulted in further increases in RR beyond single condition analyses, such as osteoporosis alone had RR of 5.3, which increased to 8.3 with serious infections and to 52.0 with obesity.

CONCLUSION:

This study demonstrated that RR of any one of 10 key conditions selected by expert opinion was ≥5 times greater in CD compared to non-CD, and nearly all dyads had RR≥5. An uncommon dyad of osteoporosis and obesity had an RR of 52.0. If clinicians consider the diagnosis of CD when the highest-risk conditions are seen, identification of this rare disease may improve.

KEYWORDS:

Cushing’s disease; delay in diagnosis; disease markers; insurance claims; relative risk

PMID:
26789346
[PubMed – as supplied by publisher]

From http://www.ncbi.nlm.nih.gov/pubmed/26789346