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Personal Stories: From my bio: (At the NIH in October 1987) The MRI still showed nothing, so they did a Petrosal Sinus Sampling Test. That scared me more than the prospect of surgery. (This test carries the risk of stroke and uncontrollable bleeding from the incision points.) Catheters were fed from my groin area to my pituitary gland and dye was injected. I could watch the whole procedure on monitors. I could not move during this test or for several hours afterwards to prevent uncontrollable bleeding from a major artery. The test did show where the tumor probably was located. Also done were more sophisticated dexamethasone suppression tests where drugs were administered by IV and blood was drawn every hour (they put a heplock in my arm so they don't have to keep sticking me). I got to go home for a weekend and then went back for the surgery... _____ From Karen's Story: https://cushingsbios.com/2016/11/18/doc-karen-pituitary-and-bla-bio/ At that time, there was evidence of a pit tumor but it wasn’t showing up on an MRI. So, I had my IPSS scheduled. An IPSS stands for Inferior Petrosal Sinus Sampling. It is done because 60 % of Cushing’s based pituitary tumors are so small that they do not show up on an MRI. Non Cushing’s experts do not know this so they often blow patients off, even after the labs show a high level of ACTH in the brain through blood work. An overproduction of the hormone ACTH from the pituitary communicates to the adrenal glands to overproduce cortisol. Well, the IPSS procedure is where they put catheters up through your groin through your body up into your head to draw samples to basically see which side of your pituitary the extra hormone is coming from, thus indicating where the tumor is. U of C is the only place in IL that does it. ... I was scheduled to get an IPSS at U of C on June 28th, 2011 to locate the tumor. Two days after the IPSS, I began having spontaneous blackouts and ended up in the hospital for 6 days. The docs out here had no clue what was happening and I was having between 4-7 blackouts a day! My life was in danger and they were not helping me! We don’t know why, but the IPSS triggered something! But, no one wanted to be accountable so they told me the passing out, which I was not doing before, was all in my head being triggered by psychological issues. They did run many tests. But, they were all the wrong tests. I say all the time; it’s like going into Subway and ordering a turkey sandwich and giving them money and getting a tuna sandwich. You would be mad! What if they told you, “We gave you a sandwich!” Even if they were to give you a dozen sandwiches; if it wasn’t turkey, it wouldn’t be the right one. This is how I feel about these tests that they ran and said were all “normal”. The doctors kept telling us that they ran all of these tests so they could cover themselves. Yet, they were not looking at the right things, even though, I (the patient) kept telling them that this was an endocrine issue and had something to do with my tumor! Well, guess how good God is?!!!! ... Fast forward, I ended up in the hospital with these blackouts after my IPSS. The doctors, including MY local endocrinologist told me there was no medical evidence for my blackouts. In fact, he told the entire treatment team that he even doubted if I even had a tumor! However, this is the same man who referred me for the IPSS in the first place! I was literally dying and no one was helping me! We reached out to Dr. Ludlam in Seattle and told him of the situation. He told me he knew exactly what was going on. For some reason, there was a change in my brain tumor activity that happened after my IPSS. No one, to this day, has been able to answer the question as to whether the IPSS caused the change in tumor activity. The tumor, for some reason, began shutting itself on and off. When it would shut off, my cortisol would drop and would put me in a state of adrenal insufficiency, causing these blackouts! Dr. Ludlam said as soon as we were discharged, we needed to fly out to Seattle so that he could help me! The hospital discharged me in worse condition then when I came in. I had a blackout an hour after discharge! But get this…The DAY the hospital sent me home saying that I did not have a pit tumor, my IPSS results were waiting for me! EVIDENCE OF TUMOR ON THE LEFT SIDE OF MY PITUITARY GLAND!!! _____ From Kirsty: https://cushingsbios.com/2013/06/25/kirsty-kirstymnz-ectopic-adrenal-bio/ The hardest of all these was what they call a petrusal vein sampling (this is where they insert a catheter into the groin through the femoral vein which goes up to the base of the brain to look at the pituitary, they do this while awake – I could actually feel them moving around in my head.) This test concluded that my Cushing’s was being caused by a tumor somewhere other than the pituitary (this only happens in 1% of cases, and there is about a 1 in 10 million chance of getting it). The question now was “where is the tumor?” _____ Find other bios with which mention this test at https://cushingsbios.com/tag/ipss/ __________ This topic on these message boards: https://cushings.invisionzone.com/forum/54-css-ct-ipss-ivp-mri-np-59-scan-octreoscan-pss-sonogram-ultrasound/ __________ Thoughts from Dr. James Findling: https://cushieblogger.com/2019/03/24/cushings-syndrome-expert-a-standout-in-clinical-practice/ Another defining moment in my career from a research perspective was when I was a fellow, I had to do a project. We were seeing a lot of patients with Cushing’s — of course, that’s why I went there — and in those days we had no good imaging. There were no CT scans, no MRI, there was no way to image the pituitary gland to find out whether there was a tumor. By the late ’70s it became obvious that some patients with Cushing’s syndrome didn’t have pituitary tumors. They had tumors in their lungs and other places, and there was no good way of sorting these patients from the pituitary patients. My mentor at UCSF, Blake Tyrrell, MD, had the idea of sampling from the jugular vein to see if there was a gradient across the pituitary. I took the project up because I didn’t think this is going to be helpful due to there being too much venous admixture in the jugular vein from other sources of cerebral venous drainage. We went into the radiology suite to do the first patient. As I was sampling blood from the peripheral veins, the interventional radiologist, David Norman, MD, says, “Would you like to sample the inferior petrosal sinus?” I said, “Why not? It sounds like a good idea to me.” That turned out to be helpful. We then studied several patients, and it eventually went to publication. Now everybody acknowledges it is necessary, maybe not in all patients with Cushing’s, but in many patients with Cushing’s to separate pituitary from nonpituitary Cushing’s syndrome. __________ Official information Patient information from Canterbury Health Limited Endocrine Services INFERIOR PETROSAL SINUS SAMPLING WITH CRH STIMULATION Introduction You have been diagnosed with Cushing's syndrome which results from excessive production of the hormone cortisol, made by the adrenal glands. In your case, the adrenal glands are being driven by excessive amounts of another hormone called ACTH. This test is to determine where that ACTH is coming from. Constant high levels of ACTH are usually caused by a tumor. Approximately 80% of cases are tumors of the pituitary gland while the remainder may occur in the lung, pancreas and other sites (known as "ectopic" sites). This test relies on the fact that if the source of your high ACTH is the pituitary gland blood levels taken from very near the gland will be higher than the blood level in an arm vein. Pituitary gland tumors are often tiny and can't be seen even with the most modern scanners. This test will help your endocrinologist to know with almost 100% certainty whether the pituitary gland is the source or if a search is needed elsewhere (for example in the lungs or abdomen). This guides treatment, for example the recommendation for Pituitary surgery. Procedure You are allowed water only from midnight the night before (nothing else to eat or drink). You will be given a light sedative, but will be awake during the procedure. You will be taken to the Radiology Department where the procedure will take place. The radiologist will place some local anesthetic into the groin on each side over the main vein that drains blood from each leg. Then a fine bore catheter will be passed up the vein, past the heart and into the major vein in the neck (the jugular vein). From there it is passed into a smaller vein that drains blood directly from the pituitary gland, known as the inferior petrosal sinus. The procedure is repeated for the other side. X-ray screening guides the radiologist to know where the catheters are positioned. A small butterfly needle is inserted into an arm vein. Once the catheters are in place, blood samples will be taken from the right and left petrosal sinus, and an arm vein at exactly the same time. After two baseline samples, a hormone called CRH is injected into the arm vein. This increases ACTH when a pituitary gland tumor is present, but has no effect on ectopic ACTH production. Further blood samples are taken for another 10 to 15 minutes, then the catheters are withdrawn. Pressure is applied to the groins to minimize bruising. Often sampling is continued from the arm vein only, for a total of 90 minutes. You will have to remain lying on your back for at least 2 hours afterwards. Risks This procedure is very safe when performed by an experienced radiologist. Rarely, there have been reports of people having a stroke at the time of this procedure but this was related to a catheter of faulty design which is now no longer used. Bruising, which is common in Cushing's syndrome, may occur after the catheters are pulled out. Some people notice flushing of the face after the CRH and rarely it can result in a fall in blood pressure. From: http://www.pituitarycenter.com/html/article1.html INFERIOR PETROSAL SINUS SAMPLING Patients who are suspected of having a pituitary tumor resulting in Cushing's syndrome may be referred for inferior petrosal sinus sampling if findings on MRI examination of the pituitary did not reveal a tumor or are inconclusive. The inferior petrosal sinus sampling procedure is performed in the radiology department. With the patient on the angiography table both groin regions are partially shaved, sterilized, and a local anesthetic is injected into the skin to provide pain relief. A tiny incision is made within the skin and a needle is inserted to puncture the femoral vein which drains blood from the leg. A small catheter is then inserted into the vein and flushed with an intravenous solution. Longer catheters are passed into the shorter catheters and advanced through the large veins traversing the torso into the neck and then into the base of the skull. Thereafter, a microcatheter is advanced through each of these larger guiding catheters and threaded into the inferior petrosal sinuses which lie along the internal aspect of the skull base and drain blood from the pituitary gland. Once these microcatheters have been positioned, contrast dye is injected and X-rays are taken to verify their position in the inferior petrosal sinuses. Next, blood samples are collected from both catheters in the inferior petrosal sinuses and from a peripheral (usually arm) vein. Thereafter, corticotropin-releasing hormone is administered through the peripheral vein. Repeat blood samples are drawn 2, 5, and 10 minutes after the injection. Additional X-rays are taken to confirm that the catheters were not dislodged from their site during the sampling procedure. Thereafter, the catheters are removed and direct pressure is applied to the groin region to decrease the likelihood of bruising. Patients are observed for 4 hours following the procedure to ensure that no bleeding from the femoral vein puncture sites will occur. Normal non-strenuous activity may be resumed 48 hours after the procedure. Sedatives and pain relievers may be administered during the procedure as necessary. A blood thinner might be used depending on the patient's anatomy and the clinical suspicion of developing a blood clot. If a blood thinner is used, this may be counteracted with medication at the conclusion of the procedure to ensure that normal blood clotting resumes while removing the catheters. Overall, the inferior petrosal sinus sampling procedure involves minimal discomfort. The risks of the procedure are small. X-rays are used but the radiation doses are minimized. Infection is controlled by using sterile technique. Some patients might have an unexpected allergic reaction to the dye used during the study. A bruise may develop within the groin. Although rare, blood clots have developed in the groin veins following this procedure. Again, steps are taken to minimize the likelihood of each and every one of these complications. ACTH levels are measured in each of the blood samples obtained during the procedure. The ratios between the petrosal sinus sampling and the peripheral vein samples are compared. The results are used to determine whether ACTH production is due to either a pituitary or a non-pituitary source. ___ From: http://www.mc.vanderbilt.edu/pituitarycenter/html/article1.html Patients who are suspected of having a pituitary tumor resulting in Cushing's syndrome may be referred for inferior petrosal sinus sampling if findings on MRI examination of the pituitary did not reveal a tumor or are inconclusive. The inferior petrosal sinus sampling procedure is performed in the radiology department. With the patient on the angiography table both groin regions are partially shaved, sterilized, and a local anesthetic is injected into the skin to provide pain relief. A tiny incision is made within the skin and a needle is inserted to puncture the femoral vein which drains blood from the leg. A small catheter is then inserted into the vein and flushed with an intravenous solution. Longer catheters are passed into the shorter catheters and advanced through the large veins traversing the torso into the neck and then into the base of the skull. Thereafter, a microcatheter is advanced through each of these larger guiding catheters and threaded into the inferior petrosal sinuses which lie along the internal aspect of the skull base and drain blood from the pituitary gland. Once these microcatheters have been positioned, contrast dye is injected and X-rays are taken to verify their position in the inferior petrosal sinuses. Next, blood samples are collected from both catheters in the inferior petrosal sinuses and from a peripheral (usually arm) vein. Thereafter, corticotropin-releasing hormone is administered through the peripheral vein. Repeat blood samples are drawn 2, 5, and 10 minutes after the injection. Additional X-rays are taken to confirm that the catheters were not dislodged from their site during the sampling procedure. Thereafter, the catheters are removed and direct pressure is applied to the groin region to decrease the likelihood of bruising. Patients are observed for 4 hours following the procedure to ensure that no bleeding from the femoral vein puncture sites will occur. Normal non-strenuous activity may be resumed 48 hours after the procedure. Sedatives and pain relievers may be administered during the procedure as necessary. A blood thinner might be used depending on the patient's anatomy and the clinical suspicion of developing a blood clot. If a blood thinner is used, this may be counteracted with medication at the conclusion of the procedure to ensure that normal blood clotting resumes while removing the catheters. Overall, the inferior petrosal sinus sampling procedure involves minimal discomfort. The risks of the procedure are small. X-rays are used but the radiation doses are minimized. Infection is controlled by using sterile technique. Some patients might have an unexpected allergic reaction to the dye used during the study. A bruise may develop within the groin. Although rare, blood clots have developed in the groin veins following this procedure. Again, steps are taken to minimize the likelihood of each and every one of these complications. ACTH levels are measured in each of the blood samples obtained during the procedure. The ratios between the petrosal sinus sampling and the peripheral vein samples are compared. The results are used to determine whether ACTH production is due to either a pituitary or a non-pituitary source. ___ From https://www.uclahealth.org/radiology/interventional-neuroradiology/inferior-petrosal-sinus-sampling The IPSS test is done in some patients to identify if there is too much ACTH is causing the excess production of cortisol, and where it is coming from. How do we do an IPSS procedure? Typically under general anesthesia, we place small tubes (catheters) into the femoral veins (the main vein draining the legs) at the level of the groin. From there, under X-ray guidance, we navigate those catheters to the main veins which drain the Pituitary gland. These are the inferior petrosal sinuses (right and left). We then draw samples from those veins and the main vein of the abdomen and test those samples for ACTH. We also take timed samples after giving a dose of medication which would normally stimulate the production of ACTH to improve the sensitivity of the test. When we get the results, the different levels of ACTH may help the endocrinologist determine where the tumor is located that is causing the adrenal gland to produce the excess cortisol. If it is from the Pituitary gland, any difference between the right and left samples may help the surgeon determine the surgical plan to remove the tumor yet preserve the normal Pituitary gland. Example of testing results: Time Right IPS Left IPS Inf Vena Cava Cortisol Baseline 1 09:32 40 pg/ml 17 18 25 mcg/dl Baseline 2 09:34 45 18 15 24 DDAVP inj 09:38 Post 2min 09:40 72 21 18 Post 5min 09:43 157 20 19 Post 10min 09:48 161 30 25 Post 15min 09:53 162 33 26 Post 30min 10:08 124 32 29 30 This example shows elevation of ACTH in the right inferior petrosal sinus, likely indicating a tumor in the right side of the pituitary gland causing Cushing’s Disease. Picture of contrast injection of the inferior petrosal sinuses: Tips of the catheters in the inferior petrosal sinuses.
Dr. Irmanie Hemphill, who first thought her weight gain was due to having a baby. Doctors at Cleveland Clinic Florida in Weston diagnosed her with a tumor in the pituitary gland in her brain. In the summer of 2019, Irmanie Hemphill gained a lot of weight, developed acne and had high blood pressure. She attributed it to her body adjusting from giving birth just six weeks prior. “I was thinking maybe it was just hormonal changes from having a baby,” said Hemphill, 38, of Pembroke Pines. But when Hemphill, a family medicine physician, saw that her nails were turning dark and she gained five pounds within a week, she knew it was something more serious. Blood tests ordered by her physician came back normal, with the exception of high levels of cortisol detected via a urine cortisol test, which she requested after researching her symptoms online. The next step was to find out where the excess cortisol was coming from: either her kidneys or her adrenal glands, which produce hormones in response to signals from the pituitary gland in the brain. The first MRI of her brain did not detect anything abnormal, so her endocrinologist attributed her symptoms to her body adjusting post-pregnancy. Hemphill sought a second opinion at Cleveland Clinic Weston, where more MRIs of her brain, combined with an Inferior Petrosal Sinus Sampling (IPSS) procedure, detected she had a tumor on her pituitary gland. That led her to be diagnosed with Cushing’s Disease — caused by excess cortisol. TWO TYPES OF PITUITARY TUMORS There are two types of pituitary tumors: those that produce active hormones, like the one Hemphill had, and those that do not, which grow in size over time and do not manifest symptoms right away. Hemphill’s tumor was producing adrenocorticotropic hormone (ACTH), which causes the adrenal gland to produce more cortisol. Many people with Cushing’s Disease experience high blood pressure and high blood sugar, muscle fatigue, easy bruising and brain fog. If left untreated, the condition can lead to pulmonary embolisms, diabetes, osteoporosis, strokes and heart attacks. “It was a little bit of relief but also sadness,” said Hemphill, of finding out her diagnosis. “I was very happy that I got a diagnosis but now it’s like, what’s the next step?” LESS INVASIVE WAY TO REMOVE A PITUITARY TUMOR Hospitals in South Florida are at the forefront in developing new research, techniques and technologies for pituitary tumors. The tiny bean-shaped pituitary gland is located at the base of the brain and controls many of the body’s hormonal and metabolic functions. Last June, neurosurgeon Dr. Hamid Borghei-Razavi of Cleveland Clinic Weston removed Hemphill’s pituitary tumor through her nose. This type of procedure allows surgeons to remove the tumor without damaging the brain. “It’s a less-invasive approach compared to 20 years ago, when pituitary tumors were removed through the cranium,” he said. “Now, with new technologies, more than 95% of pituitary tumors can be removed through the nose.” The procedure takes just a few hours to complete, based on the size and location of the tumor. Patients usually stay at the hospital for one to two days afterward for observation. The removal of Hemphill’s tumor, which was three to four millimeters in size, put an end to her Cushing’s Disease and her symptoms, though it took six months to a year for Hemphill to feel normal. (She was prescribed cortisol for six months until her adrenal glands could restart producing cortisol on their own.) “Sometimes it’s very hard to make a diagnosis for pituitary tumors because we don’t see them in the MRIs,” said Borghei-Razavi. “We call it MRI Negative Cushing’s Syndrome. It means we don’t see it in the MRI, but the cells are there,” he said. Borghei-Razavi and Hemphill credit the Inferior Petrosal Sinus Sampling (IPSS) test as pinpointing her tumor. Cleveland Clinic Weston is among only a handful of medical practices in South Florida that use this technique. Three Ways to Remove the Tumor Most pituitary tumors are benign. The challenge is when it comes to removing the tumor. “Pituitary tumors come in all shapes and sizes,” says Dr. Zoukaa Sargi, a head and neck surgeon at Sylvester Comprehensive Cancer Center at the University of Miami. “There are non-functional tumors that do not secrete hormones that can reach extreme sizes of up to 10 centimeters before coming to medical attention. This is the equivalent of the size of a grapefruit,” he says. “Then there are functional tumors that produce hormones that are typically discovered much sooner and can be only a few millimeters in size before coming to medical attention. A small proportion, less than 1%, are malignant,” he adds. There are three treatment options for pituitary tumors: surgical removal, medical therapy and radiation. “Medical therapy is only applicable in certain functional tumors that produce hormones,” says Dr. Ricardo Komotar, a neurosurgeon who is director of the Sylvester Comprehensive Cancer Center Brain Tumor Initiative. “Radiation is an option primarily for inoperable tumors with high surgical risk. Surgical removal is the optimal treatment in the vast majority of pituitary cases, conferring the greatest benefit with the lowest morbidity,” he says. Dr. Rupesh Kotecha, chief of radiosurgery at Miami Cancer Institute (MCI), part of Baptist Health South Florida, says there are a number of different hormones that the pituitary gland can secrete. “Prolactin is the most common form of pituitary adenoma that’s functioning and accounts for 30% to 50%,” he said. Excess prolactin can cause the production of breast milk in men and in women who are not pregnant or breastfeeding. Kotecha said the next most common are growth-hormone secreting tumors, which occur in 10% of patients. ACTH-secreting adenomas — the kind that Hemphill had — account for 5% of patients, while 1% secrete TSH, which causes the thyroid gland to be overactive. MCI’s Proton Therapy delivers high-dose radiation that treats the tumor’s area, allowing for surrounding tissues and organs to be spared from the effects of radiation. “The pituitary gland essentially sits in the middle of the brain,” says Kotecha. “It’s sitting in the middle of all of these critical structures.” From https://www.miamiherald.com/living/health-fitness/article251653033.html
Minimally invasive diagnostic methods and transnasal surgery may lead to remission in nearly all children with Cushing’s disease, while avoiding more aggressive approaches such as radiation or removal of the adrenal glands, a study shows. The study, “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,” was published in the Journal of Pediatric Endocrinology and Metabolism. Normally, the pituitary produces adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol. When a patient has a pituitary tumor, that indirectly leads to high levels of cortisol, leading to development of Cushing’s disease (CD). In transnasal surgery (TNS), a surgeon goes through the nose using an endoscope to remove a pituitary tumor. The approach is the first-choice treatment for children with Cushing’s disease due to ACTH-secreting adenomas — or tumors — in the pituitary gland. Micro-adenomas, defined as less than 4 mm, are more common in children and need surgical expertise for removal. It is necessary to determine the exact location of the tumor before conducting the surgery. Additionally, many surgeons perform radiotherapy or bilateral adrenalectomy (removal of both adrenal glands) after the surgery. However, these options are not ideal as they can be detrimental to children who need to re-establish normal growth and development patterns. Dieter K. Lüdecke, a surgeon from Germany’s University of Hamburg, has been able to achieve nearly 100% remission while minimizing the need for pituitary radiation or bilateral adrenalectomy. In this study, researchers looked at how these high remission rates can be achieved while minimizing radiotherapy or bilateral adrenalectomy. Researchers analyzed 100 patients with pediatric CD who had been referred to Lüdecke for surgery from 1980-2009. Data was published in two separate series — series 1, which covers patients from 1980-1995, and series 2, which covers 1996-2009. All the surgeries employed direct TNS. Diagnostic methods for CD have improved significantly over the past 30 years. Advanced endocrine diagnostic investigations, such as testing for levels of salivary cortisol in the late evening and cortisol-releasing hormone tests, have made a diagnosis of CD less invasive. This is particularly important for excluding children with obesity alone from children with obesity and CD. Methods to determine the precise location of micro-adenomas have also improved. The initial methodology to localize tumors was known as inferior petrosal sinus sampling (IPSS), an invasive procedure in which ACTH levels are sampled from the veins that drain the pituitary gland. In series 1, IPSS was performed in 24% of patients, among which 46% were found to have the wrong tumor location. Therefore, IPSS was deemed invasive, risky, and unreliable for this purpose. All adenomas were removed with extensive pituitary exploration. Two patients in series 1 underwent early repeat surgery; all were successful. Lüdecke introduced intraoperative cavernous sinus sampling (CSS), an improved way to predict location of adenomas. This was found to be very helpful in highly select cases and could also be done preoperatively for very small adenomas. In series 2, CSS was used in only 15% of patients thanks to improved MRI and endocrinology tests. All patients who underwent CSS had correct localization of their tumors, indicating its superiority over IPSS. In series 2, three patients underwent repeat TNS, which was successful. In these recurrences, TNS minimized the need for irradiation. The side effects of TNS were minimal. Recurrence rate in series 1 was 16% and 11% in series 2. While Lüdecke’s patients achieved a remission rate of 98%, other studies show cure rates of 45-69%. Only 4% of patients in these two series received radiation therapy. “Minimally invasive unilateral, microsurgical TNS is important functionally for both the nose and pituitary,” the researchers concluded. “Including early re-operations, a 98% remission rate could be achieved and the high risk of pituitary function loss with radiotherapy could be avoided.” From https://cushingsdiseasenews.com/2018/09/04/minimally-invasive-methods-yield-high-remission-in-cushings-disease-children/
By: SHERRY BOSCHERT, Family Practice News Digital Network SAN FRANCISCO – The size of a pituitary tumor on magnetic resonance imaging in a patient with ACTH-dependent Cushing’s syndrome can’t differentiate between etiologies, but combining that information with biochemical test results could help avoid costly and difficult inferior petrosal sinus sampling in some patients, a study of 131 cases suggests. If MRI shows a pituitary tumor larger than 6 mm in size, the finding is 40% sensitive and 96% specific for a diagnosis of Cushing’s disease as the cause of adrenocorticotropic hormone (ACTH)-dependent Cushing’s syndrome, and additional information from biochemical testing may help further differentiate this from ectopic ACTH secretion, Dr. Divya Yogi-Morren and her associates reported at the Endocrine Society’s Annual Meeting. Pituitary tumors were seen on MRI in 6 of 26 patients with ectopic ACTH secretion (23%) and 73 of 105 patients with Cushing’s disease (69%), with mean measurements of 4.5 mm in the ectopic ACTH secretion group and 8 mm in the Cushing’s disease group. All but one tumor in the ectopic ACTH secretion group were 6 mm or smaller in diameter, but one was 14 mm. Because pituitary "incidentalomas" as large as 14 mm can be seen in patients with ectopic ACTH secretion, the presence of a pituitary tumor can’t definitively discriminate between ectopic ACTH secretion and Cushing’s disease, said Dr. Yogi-Morren, a fellow at the Cleveland Clinic. That finding contradicts part of a 2003 consensus statement that said the presence of a focal pituitary lesion larger than 6 mm on MRI could provide a definitive diagnosis of Cushing’s disease, with no further evaluation needed in patients who have a classic clinical presentation and dynamic biochemical testing results that are compatible with a pituitary etiology (J. Clin. Endocrinol. Metab. 2003;88:5593-602). The 6-mm cutoff, said Dr. Yogi-Morren, came from an earlier study reporting that 10% of 100 normal, healthy adults had focal pituitary abnormalities on MRI ranging from 3 to 6 mm in diameter that were consistent with a diagnosis of asymptomatic pituitary adenomas (Ann. Intern. Med. 1994;120:817-20). A traditional workup of a patient with ACTH-dependent Cushing’s syndrome might include a clinical history, biochemical testing, neuroimaging, and an inferior petrosal sinus sampling (IPSS). Biochemical testing typically includes tests for hypokalemia, measurement of cortisol and ACTH levels, a high-dose dexamethasone suppression test, and a corticotropin-releasing hormone (CRH) stimulation test. Although IPSS is the gold standard for differentiating between the two etiologies, it is expensive and technically difficult, especially in institutions that don’t regularly do the procedure, so it would be desirable to avoid IPSS if it’s not needed in a subset of patients, Dr. Yogi-Morren said. The investigators reviewed charts from two centers (the Cleveland Clinic and the M.D. Anderson Cancer Center, Houston) for patients with ACTH-dependent Cushing’s syndrome seen during 2000-2012. ACTH levels were significantly different between groups, averaging 162 pg/mL (range, 58-671 pg/mL) in patients with ectopic ACTH secretion, compared with a mean 71 pg/mL in patients with Cushing’s disease (range, 16-209 pg/mL), she reported. Although there was some overlap between groups in the range of ACTH levels, all patients with an ACTH level higher than 210 pg/mL had ectopic ACTH secretion. Median serum potassium levels at baseline were 2.9 mmol/L in the ectopic ACTH secretion group and 3.8 mmol/L in the Cushing’s disease group, a significant difference. Again, there was some overlap between groups in the range of potassium levels, but all patients with a baseline potassium level lower than 2.7 mmol/L had ectopic ACTH secretion, she said. Among patients who underwent a high-dose dexamethasone suppression test, cortisol levels decreased by less than 50% in 88% of patients with ectopic ACTH secretion and in 26% of patients with Cushing’s disease. Most patients did not undergo a standardized, formal CRH stimulation test, so investigators extracted the ACTH response to CRH in peripheral plasma during the IPSS test. As expected, they found a significantly higher percent increase in ACTH in response to CRH during IPSS in the Cushing’s disease group, ranging up to more than a 1,000% increase. In the ectopic ACTH secretion group, 40% of patients did have an ACTH increase greater than 50%, ranging as high as a 200%-300% increase in ACTH in a couple of patients. "Although there was some overlap in the biochemical testing, it is possible that it provides some additional proof to differentiate between ectopic ACTH secretion and Cushing’s disease," Dr. Yogi-Morren said. In the ectopic ACTH secretion group, the source of the secretion remained occult in seven patients. The most common identifiable cause was a bronchial carcinoid tumor, in six patients. Three patients each had small cell lung cancer, a thymic carcinoid tumor, or a pancreatic neuroendocrine tumor. One patient each had a bladder neuroendocrine tumor, ovarian endometrioid cancer, medullary thyroid cancer, or a metastatic neuroendocrine tumor from an unknown primary cancer. The ectopic ACTH secretion group had a median age of 41 years and was 63% female. The Cushing’s disease group had a median age of 46 years and was 76% female. Dr. Yogi-Morren reported having no financial disclosures. email@example.com On Twitter @sherryboschert From Famiiy Practice News