A Challenging Diagnosis of Cushing’s Syndrome in Primary Care: A Case Report

Posted on May 11, 2026 by MaryO

Abstract

Cushing’s syndrome is a rare endocrine disorder characterized by an insidious course and multisystem manifestations, often leading to delayed diagnosis due to its nonspecific presentation. A 52-year-old woman with a history of type 2 diabetes mellitus and hypertension was followed in primary care for persistent musculoskeletal pain and worsening metabolic control, initially attributed to poor treatment adherence. Her condition progressively led to significant functional impairment, requiring the use of crutches for ambulation and ultimately resulting in medical retirement due to disability. After presenting with abdominal pain, a computed tomography scan incidentally revealed a 35 mm left adrenal mass suggestive of an adenoma. In light of the clinical context, further evaluation confirmed adrenocorticotropic hormone (ACTH)-independent hypercortisolism. The patient underwent left adrenalectomy and remains under clinical follow-up, with progressive improvement in metabolic parameters and functional status. This case highlights the importance of reassessing persistent symptoms and appropriately evaluating incidental findings in primary care, as well as the potential for significant functional decline in undiagnosed cases. Early recognition of atypical presentations may facilitate the diagnosis of rare endocrine disorders.

Introduction

Cushing’s syndrome is a rare endocrine disorder caused by prolonged exposure to excessive cortisol levels. Its clinical presentation is often insidious and characterized by multisystem involvement, including arterial hypertension, diabetes mellitus, cutaneous changes, osteoporosis, and muscle weakness. These manifestations are frequently nonspecific, contributing to delayed diagnosis and underrecognition by healthcare professionals [1,2].

In primary care, a patient-centered approach combined with longitudinal follow-up allows the identification of progressive and persistent changes, as well as the functional impact of symptoms. This case illustrates the role of the family physician in reassessing persistent complaints and integrating incidental findings, ultimately leading to the diagnosis of adrenocorticotropic hormone (ACTH)-independent hypercortisolism of adrenal origin.

Case Presentation

A 52-year-old female factory worker with a history of type 2 diabetes mellitus and arterial hypertension was regularly followed in a primary care setting. She repeatedly reported generalized musculoskeletal pain and progressive functional decline over several years.

Despite evaluation by multiple hospital specialties and prolonged physiotherapy, she maintained significant pain complaints with increasing limitation of daily activities. Glycated hemoglobin (HbA1c) was 8.6%, later 7.8% (reference: 4.0-5.6%) after therapeutic adjustment. Blood pressure was 170/90 mmHg, subsequently 153/100 mmHg. Lipid profile showed total cholesterol 264 mg/dL (reference: <200 mg/dL), low-density lipoprotein (LDL) cholesterol 175 mg/dL (reference: <130 mg/dL), and triglycerides 212 mg/dL (reference: <150 mg/dL). Despite treatment intensification, these parameters remained above target.

In parallel, her functional status progressively worsened, requiring assistance for ambulation or the use of crutches. This decline ultimately led to medical retirement due to disability.

Approximately three years after symptom onset, she presented to a private hospital emergency department with a six-month history of painful swelling in the left hypochondrium. Abdominal computed tomography revealed a 35 mm solid nodular lesion in the left adrenal gland, suggestive of an adenoma (Figure 1).

Abdominal-computed-tomography-scan-showing-left-adrenal-mass
Figure 1: Abdominal computed tomography scan showing left adrenal mass

Axial abdominal CT image demonstrating a 35 mm solid nodular lesion in the left adrenal gland (arrow), consistent with an adrenal adenoma.

At a subsequent primary care consultation, she presented with moon facies, facial plethora, proximal muscle atrophy, and scattered ecchymoses. Bone densitometry revealed severe osteoporosis (lumbar spine T-score −4.2, femoral T-score −2.6) (Figure 2) [3,4].

Bone-densitometry-showing-severe-osteoporosis
Figure 2: Bone densitometry showing severe osteoporosis

(A) Lumbar spine dual-energy X-ray absorptiometry (DEXA) scan demonstrating severe osteoporosis (T-score −4.2).
(B) Femoral DEXA scan showing reduced bone mineral density (T-score −2.6).

Laboratory studies showed elevated serum cortisol (727 nmol/L; reference: 171-536 nmol/L) with suppressed morning ACTH (1.5 ng/L; reference: 7.2-63.3 ng/L). Based on these findings, she was referred to endocrinology. In the endocrinology department, a 1 mg overnight dexamethasone suppression test showed cortisol of 637.24 nmol/L (reference: 171-536 nmol/L), confirming ACTH-independent hypercortisolism [1,2].

She subsequently underwent laparoscopic transperitoneal left adrenalectomy without complications. Histopathological examination confirmed an adrenocortical adenoma, showing a well-circumscribed lesion with diffuse architecture and cortical atrophy of the surrounding parenchyma. No evidence of necrosis, vascular invasion, or capsular invasion was identified. Immunohistochemical analysis demonstrated CYP11B1 positivity and CYP11B2 negativity, consistent with a cortisol-producing adenoma.

Following surgery, the patient remained under follow-up, with progressive improvement in metabolic parameters and functional status.

A timeline summarizing the clinical course, investigations, and management is presented in Figure 3.

Timeline-of-clinical-events,-investigations-and-management.
Figure 3: Timeline of clinical events, investigations and management.

ACTH: adrenocorticotropic hormone. Created by the authors using Canva (Sydney, Australia).

Discussion

Cushing’s syndrome is a rare condition, with an estimated incidence of two to three cases per million people per year [1]. Its clinical presentation is variable and often masked by common comorbidities such as diabetes mellitus and hypertension, which may delay diagnosis [2]. This overlap frequently contributes to diagnostic delay, often extending over several years [1,2].

Adrenal incidentalomas are increasingly identified due to widespread use of imaging, and their evaluation requires careful hormonal assessment to exclude functional lesions [5]. In this case, the incidental finding of an adrenal mass, combined with clinical suspicion, prompted further investigation and ultimately led to diagnosis. The progressive and multisystem nature of hypercortisolism often results in significant morbidity, including severe osteoporosis and functional decline, as observed in this patient [3]. Chronic exposure to excess cortisol is known to negatively impact bone metabolism and increase fracture risk [3].

The 1 mg overnight dexamethasone suppression test is widely used as an initial screening tool, with a cortisol cut-off of <1.8 μg/dL providing high sensitivity for the diagnosis of Cushing’s syndrome [1,2].

The holistic and continuous approach of the family physician allows recognition of subtle clinical changes and the functional impact of symptoms. This role is particularly relevant in slowly progressive and multisystem diseases such as Cushing’s syndrome.

It is important to note that patients with frequent consultations and persistent complaints may have their concerns undervalued. The tendency to attribute such presentations to anxiety, low pain tolerance, or poor adherence is understandable in a high-demand clinical setting but may contribute to delayed diagnosis of serious conditions.

Conclusions

This case highlights the importance of the family physician in recognizing and valuing persistent symptoms and their functional impact. The longitudinal follow-up was essential in raising suspicion and guiding diagnosis. In patients with repeated complaints, careful clinical assessment is crucial to avoid underestimation of potentially serious conditions. Particular attention should be given to unexplained functional decline, even when symptoms appear nonspecific. Maintaining clinical vigilance is fundamental to improving patient outcomes.

References

  1. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, Montori VM: The diagnosis of Cushing’s syndrome: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2008, 93:1526-40. 10.1210/jc.2008-0125
  2. Fleseriu M, Auchus R, Bancos I, et al.: Consensus on diagnosis and management of Cushing’s disease: a guideline update. Lancet Diabetes Endocrinol. 2021, 9:847-75. 10.1016/S2213-8587(21)00235-7
  3. Kanis JA, Cooper C, Rizzoli R, Reginster JY: European guidance for the diagnosis and management of osteoporosis in postmenopausal women. Osteoporos Int. 2019, 30:3-44. 10.1007/s00198-018-4704-5
  4. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis. (1994). https://iris.who.int/handle/10665/39142.
  5. Young WF Jr, Kebebew E: Evaluation and management of the adrenal incidentaloma. UpToDate. Connor RF (ed): Wolters Kluwer, Waltham; 2026.

From https://www.cureus.com/articles/480975-a-challenging-diagnosis-of-cushings-syndrome-in-primary-care-a-case-report#!/

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New discoveries offer possible Cushing’s disease cure

Posted on April 27, 2026 by MaryO

LOS ANGELES — More than a century has passed since the neurosurgeon and pathologist Harvey Cushing first discovered the disease that would eventually bear his name, but only recently have several key discoveries offered patients with the condition real hope for a cure, according to a speaker here.

There are several challenges clinicians confront in the diagnosis and treatment of Cushing’s disease, Shlomo Melmed, MB, ChB, FRCP, MACP, dean, executive vice president and professor of medicine at Cedars-Sinai Medical Center in Los Angeles, said during a plenary presentation. Patients who present with Cushing’s disease typically have depression, impaired mental function and hypertension and are at high risk for stroke, myocardial infarction, thrombosis, dyslipidemia and other metabolic disorders, Melmed said. Available therapies, which range from surgery and radiation to the somatostatin analogue pasireotide (Signifor LAR, Novartis), are often followed by disease recurrence. Cushing’s disease is fatal without treatment; the median survival if uncontrolled is about 4.5 years, Melmed said.

“This truly is a metabolic, malignant disorder,” Melmed said. “The life expectancy today in patients who are not controlled is apparently no different from 1930.”

The outlook for Cushing’s disease is now beginning to change, Melmed said. New targets are emerging for treatment, and newly discovered molecules show promise in reducing the secretion of adrenocorticotropic hormone (ACTH) and pituitary tumor size.

“Now, we are seeing the glimmers of opportunity and optimism, that we can identify specific tumor drivers — SST5, [epidermal growth factor] receptor, cyclin inhibitors — and we can start thinking about personalized, precision treatment for these patients with a higher degree of efficacy and optimism than we could have even a year or 2 ago,” Melmed said. “This will be an opportunity for us to broaden the horizons of our investigations into this debilitating disorder.”

Challenges in diagnosis, treatment

Overall, about 10% of the U.S. population harbors a pituitary adenoma, the most common type of pituitary disorder, although the average size is only about 6 mm and 40% of them are not visible, Melmed said. In patients with Cushing’s disease, surgery is effective in only about 60% to 70% of patients for initial remission, and overall, there is about a 60% chance of recurrence depending on the surgery center, Melmed said. Radiation typically leads to hypopituitarism, whereas surgical or biochemical adrenalectomy is associated with adverse effects and morbidity. Additionally, the clinical features of hypercortisolemia overlap with many common illnesses, such as obesity, hypertension and type 2 diabetes.

“There are thousands of those patients for every patient with Cushing’s disease who we will encounter,” Melmed said.

The challenge for the treating clinician, Melmed said, is to normalize cortisol and ACTH with minimal morbidity, to resect the tumor mass or control tumor growth, preserve pituitary function, improve quality of life and achieve long-term control without recurrence.

“This is a difficult challenge to meet for all of us,” Melmed said.

Available options

Pituitary surgery is typically the first-line option offered to patients with Cushing’s disease, Melmed said, and there are several advantages, including rapid initial remission, a one-time cost and potentially curing the disease. However, there are several disadvantages with surgery; patients undergoing surgery are at risk for postoperative venous thromboembolism, persistent hypersecretion of ACTH, adenoma persistence or recurrence, and surgical complications.

Second-line options are repeat surgery, radiation, adrenalectomy or medical therapy, each with its own sets of pros and cons, Melmed said.

“The reality of Cushing’s disease — these patients undergo first surgery and then recur, second surgery and then recur, then maybe radiation and then recur, and then they develop a chronic illness, and this chronic illness is what leads to their demise,” Melmed said. “Medical therapy is appropriate at every step of the spectrum.”

Zebrafish clues

Searching for new options, Melmed and colleagues introduced a pituitary tumor transforming gene discovered in his lab into zebrafish, which caused the fish to develop the hallmark features of Cushing’s disease: high cortisol levels, diabetes and cardiovascular disease. In the fish models, researchers observed that cyclin E activity, which drives the production of ACTH, was high.

Melmed and colleagues then screened zebrafish larvae in a search for cyclin E inhibitors to derive a therapeutic molecule and discovered R-roscovitine, shown to repress the expression of proopiomelanocortin (POMC), the pituitary precursor of ACTH.

In fish, mouse and in vitro human cell models, treatment with R-roscovitine was associated with suppressed corticotroph tumor signaling and blocked ACTH production, Melmed said.

“Furthermore, we asked whether or not roscovitine would actually block transcription of the POMC gene,” Melmed said. “It does. We had this molecule (that) suppressed cyclin E and also blocks transcription of POMC leading to blocked production of ACTH.”

In a small, open-label, proof-of-principal study, four patients with Cushing’s disease who received roscovitine for 4 weeks developed normalized urinary free cortisol, Melmed said.

Currently, the FDA Office of Orphan Products Development is funding a multicenter, phase 2, open-label clinical trial that will evaluate the safety and efficacy of two of three potential doses of oral roscovitine (seliciclib) in patients with newly diagnosed, persistent or recurrent Cushing disease. Up to 29 participants will be treated with up to 800 mg per day of oral seliciclib for 4 days each week for 4 weeks and enrolled in sequential cohorts based on efficacy outcomes.

“Given the rarity of the disorder, it will probably take us 2 to 3 years to recruit patients to give us a robust answer,” Melmed said. “This zebrafish model was published in 2011, and we are now in 2019. It has taken us 8 years from publication of the data to, today, going into humans with Cushing’s. Hopefully, this will light the pathway for a phase 2 trial.”

‘ Offering optimism’

Practitioners face a unique paradigm when treating patients with Cushing’s disease, Melmed said. Available first- and second-line therapy options often are not a cure for many patients, who develop multimorbidity and report a low quality of life.

“Then, we are kept in this difficult cycle of what to do next and, eventually, running out of options,” Melmed said. “Now, we can look at novel, targeted molecules and add those to our armamentarium and at least offer our patients the opportunity to participate in trials, or at least offer the optimism that, over the coming years, there will be a light at the end of the tunnel for their disorder.”

Melmed compared the work to Lucas Cranach’s Fons Juventutis (The Fountain of Youth). The painting, completed in 1446, shows sick people brought by horse-drawn ambulance to a pool of water, only to emerge happy and healthy.

“He was imagining this ‘elixir of youth’ (that) we could offer patients who are very ill and, in fact, that is what we as endocrinologists do,” Melmed said. “We offer our patients these elixirs. These Cushing’s patients are extremely ill. We are trying with all of our molecular work and our understanding of pathogenesis and signaling to create this pool of water for them, where they can emerge with at least an improved quality of life and, hopefully, a normalized mortality. That is our challenge.” – by Regina Schaffer

Reference:

Melmed S. From zebrafish to humans: translating discoveries for the treatment of Cushing’s disease. Presented at: AACE Annual Scientific and Clinical Congress; April 24-28, 2019; Los Angeles.

Disclosure: Melmed reports no relevant financial disclosures.

 

From https://www.healio.com/endocrinology/neuroendocrinology/news/online/%7B585002ad-640f-49e5-8d62-d1853154d7e2%7D/new-discoveries-offer-possible-cushings-disease-cure

Filed under: Cushing's, Meetings and Conferences, pituitary, symptoms, Treatments | Tagged: , , , , , , , , , , , , | Leave a comment »

Blood Lipid Levels Linked to High Blood Pressure in Cushing’s Disease Patients

Posted on April 25, 2026 by MaryO

High lipid levels in the blood may lead to elevated blood pressure in patients with Cushing’s disease, a Chinese study shows.

The study, “Evaluation of Lipid Profile and Its Relationship with Blood Pressure in Patients with Cushing’s Disease,” appeared in the journal Endocrine Connections.

Patients with Cushing’s disease often have chronic hypertension, or high blood pressure, a condition that puts them at risk for cardiovascular disease. While the mechanisms of Cushing’s-related high blood pressure are not fully understood, researchers believe that high levels of cortisol lead to chronic hypertension through increased cardiac output, vascular resistance, and reactivity to blood vessel constrictors.

In children and adults with Cushing’s syndrome, the relationship between increased cortisol levels and higher blood pressure has also been reported. Patients with Cushing’s syndrome may remain hypertensive even after surgery to lower their cortisol levels, suggesting their hypertension is caused by changes in blood vessels.

Studies have shown that Cushing’s patients have certain changes, such as increased wall thickness, in small arteries. The renin-angiotensin system, which can be activated by glucocorticoids like cortisol, is a possible factor contributing to vascular changes by increasing the uptake of LDL-cholesterol (LDL-C) — the “bad” cholesterol — in vascular cells.

Prior research showed that lowering cholesterol levels could benefit patients with hypertension and normal lipid levels by decreasing the stiffness of large arteries. However, the link between blood lipids and hypertension in Cushing’s disease patients is largely unexplored.

The study included 84 patients (70 women) referred to a hospital in China for evaluation and diagnosis of Cushing’s disease. For each patient, researchers measured body mass index, blood pressure, lipid profile, and several other biomarkers of disease.

Patients with high LDL-cholesterol had higher body mass index, blood pressure, cholesterol, triglycerides, and apolipoproteinB (apoB), a potential indicator of atherosclerosis and cardiovascular disease.

Data further revealed an association between blood pressure and lipid profile, including cholesterol, triglycerides, apoB and LDL-c. “The results strongly suggested that CHO (cholesterol), LDL-c and apoB might predict hypertension more precisely in [Cushing’s disease],” the scientists wrote.

They further add that high cholesterol, LDL-cholesterol, and apoB might be contributing to high blood pressure by increasing vessel stiffness.

Additional analysis showed that patients with higher levels of “bad” cholesterol — 3.37 mmol/L or higher — had higher blood pressure. This finding remained true, even when patients were receiving statins to lower their cholesterol levels.

No association was found between blood pressure and plasma cortisol, UFC, adrenocorticotropic hormone, or glucose levels in Cushing’s disease patients.

These findings raise some questions on whether lipid-lowering treatment for high blood pressure and cardiovascular disease would be beneficial for Cushing’s disease patients. Further studies addressing this question are warranted.

Adapted from https://cushingsdiseasenews.com/2018/04/24/blood-pressure-linked-lipid-levels-cushings-disease-study/

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Diagnosis and Differential Diagnosis of Cushing’s Syndrome

Posted on April 8, 2026 by MaryO

D. Lynn Loriaux, M.D., Ph.D.

N Engl J Med 2017; 376:1451-1459April 13, 2017DOI: 10.1056/NEJMra1505550

More than a century ago, Harvey Cushing introduced the term “pluriglandular syndrome” to describe a disorder characterized by rapid development of central obesity, arterial hypertension, proximal muscle weakness, diabetes mellitus, oligomenorrhea, hirsutism, thin skin, and ecchymoses.1 Cushing knew that this syndrome was associated with adrenal cancer,2 and he suspected that some cases might have a pituitary component.

On September 6, 1911, he performed a craniotomy on one of his patients (referred to as Case XLV) but found no pituitary tumor.3 In his description of the case, he goes on to say that “we may perchance be on the way toward the recognition of the consequences of hyperadrenalism.”2 With time, it became clear that the disorder could be caused by small basophilic adenomas of the pituitary gland,4 and the pluriglandular syndrome became known as Cushing’s syndrome.

Fuller Albright provided the next conceptual advance in an extraordinary report, published in the first volume of the Laurentian Hormone Conference, “The Effects of Hormones on Osteogenesis in Man”5:

It has been our concept that protoplasm in general, like the protoplasmic matrix of bone, is constantly being anabolized and catabolized at one and the same time; a factor which increases catabolism would lead to very much the same net result as a factor which inhibits anabolism, but there would be some differences; it is my belief that the “S” hormone [cortisol] is anti-anabolic rather than catabolic. . . . The anti-anabolism . . . is contrasted with the increased anabolism due to an excess of the “N” hormone [testosterone] in the adreno-genital syndrome. This anti-anabolism of protoplasm in Cushing’s syndrome accounts for not only the osteoporosis, but the muscular weakness, the thin skin, probably the easy bruisability, and possibly the atrophy of the lymphoid tissues and thymus.

Nonetheless, in the intervening years, the physical examination of patients suspected to have glucocorticoid excess focused on the anabolic changes, essentially to the exclusion of the antianabolic changes. With the rapid increase in the rate of obesity in the general population, Cushing’s syndrome can no longer be reliably separated from the metabolic syndrome of simple obesity on the basis of anabolic signs alone. However, the antianabolic changes in Cushing’s syndrome are very effective in making this distinction. This review focuses on the problems introduced into the diagnosis and differential diagnosis of Cushing’s syndrome by the obesity epidemic and on ways to alter the traditional approach, using the antianabolic changes of excess cortisol to separate patients with Cushing’s syndrome from obese patients with the insulin-resistant metabolic syndrome.

PHYSICAL EXAMINATION

Andreas Vesalius (1514–1564) published his transformational work on human anatomy, De Humani Corporis Fabrica Libri Septem, in 1543. It is the book that corrected many of Galen’s anatomical errors. The book was met with considerable hostility. As an example, Jacobus Sylvius (Jacques Dubois, 1478–1555), the world’s leading anatomist at the time and Vesalius’s former mentor, on being asked his opinion of the work, replied, “Galen is not wrong. It is man that has changed, and not for the better.”6 This was not true then, but it is true now.

Approximately one third of the U.S. population is obese. The worldwide prevalence of the metabolic syndrome among obese persons is conservatively estimated at 10%; that is, approximately 12 million people have the obesity-related metabolic syndrome.7,8 The clinical picture of this syndrome is almost the same as that of Cushing’s syndrome.9,10 The prevalence of undiagnosed Cushing’s syndrome is about 75 cases per 1 million population, or 24,000 affected persons. On the basis of these prevalence estimates, the chance that a person with obesity, hypertension, hirsutism, type 2 diabetes, and dyslipidemia has Cushing’s syndrome is about 1 in 500. In Harvey Cushing’s era, when obesity was rare, making the diagnosis of Cushing’s syndrome was the most certain aspect of the management of this disorder. Today, making the diagnosis is the least certain aspect in the care of patients with Cushing’s syndrome.

The metabolic syndrome caused by glucocorticoid hypersecretion can be differentiated from the obesity-associated metabolic syndrome with the use of a careful assessment of Albright’s antianabolic effects of cortisol. These effects — osteopenia, thin skin, and ecchymoses — are present in patients with Cushing’s syndrome but not in patients with simple obesity.

Patients in whom osteoporosis is diagnosed radiographically are more likely to have Cushing’s syndrome than those who do not have osteoporosis, with a positive likelihood ratio of 11.11-13 Today, a z score of −2 at the lumbar spine supports this criterion. Skinfold thickness is conveniently measured with an electrocardiographic caliper that has the points dulled with a sharpening stone and the screws tightened so that the gap is maintained when the caliper is removed from the skinfold. The skin over the proximal phalanx of the middle finger of the nondominant hand is commonly used for this measurement

 

(Figure 1 FIGURE 1Measurement of Skinfold Thickness.). A thickness of less than 2 mm is considered to be thin skin. Patients who have thin skin are more likely to have Cushing’s syndrome, with a positive likelihood ratio of 116

 

(Figure 2 FIGURE 2 Comparison of Skinfold Thickness in Patients with Cushing’s Syndrome and Those with Other Conditions Related to Insulin Resistance.).13-15 Finally, patients who have three or more ecchymoses that are larger than 1 cm in diameter and not associated with trauma such as venipuncture are more likely to have Cushing’s syndrome than are patients without such findings, with a positive likelihood ratio of 4.13,16

If we know the prevalence of undiagnosed Cushing’s syndrome in the population of persons with the obesity-related metabolic syndrome, we can begin to calculate the probability that a person has Cushing’s syndrome, using the likelihood ratios for the antianabolic features observed on physical examination. Likelihood ratios can be converted into probabilities with the use of Bayes’ theorem. This conversion is markedly facilitated by the Fagan nomogram for this purpose.17

The prevalence of undiagnosed Cushing’s syndrome is not known, but it can be estimated. Two persons per 1 million population die from adrenal cancer every year.18 The current life span for patients with adrenocortical carcinoma, after diagnosis, is between 2 and 4 years.19,20 Allowing 3 years to make the diagnosis, the prevalence of undiagnosed Cushing’s syndrome is 6 cases per million. In most case series of Cushing’s syndrome, an average of 8% of patients have adrenal carcinoma.21 If 6 per million is 8% of the group, the total Cushing’s syndrome group is 75 persons per million, or 24,000 persons. If all 24,000 patients are included in the metabolic syndrome group, comprising 12 million people, the prevalence of Cushing’s syndrome is 0.002, or 0.2%. With a probability of 0.2% and a likelihood ratio of 116 for thin skin, 18 for osteopenia, and 4 for ecchymoses, the probability that a patient with these three findings has Cushing’s syndrome is 95%.

URINARY FREE CORTISOL

The diagnosis of all endocrine diseases requires a clinical presentation that is compatible with the disease, as well as identification of the pathophysiological cause. An assessment for excess glucocorticoid effects can be made by measuring the 24-hour urinary free cortisol level.22 There are two kinds of free cortisol: plasma protein-unbound cortisol and cortisol unconjugated to sulfuric or hyaluronic acid. Protein-unbound cortisol is filtered in the glomerulus and then reabsorbed in the collecting system. About 3% of filtered cortisol ends up in the urine. This free cortisol in the urine is unconjugated. Thus, the urinary free cortisol level is a direct reflection of the free, bioactive cortisol level in plasma. The free cortisol level is quantified in a 24-hour urine sample by averaging the increased secretion of cortisol in the morning and the decreased secretion in the afternoon and at night. Urinary creatinine is also measured to determine whether the collection is complete. Creatinine levels of less than 1.5 g per day for men and less than 1 g per day for women indicate incomplete collection, and the test should be repeated in patients with these levels.

Unconjugated cortisol can be extracted directly from urine with a nonpolar lipid solvent. After extraction, the cortisol is purified by means of high-pressure liquid chromatography and then quantified with a binding assay, usually radioimmunoassay. Free cortisol also can be quantitated directly by means of mass spectroscopy. The urinary free cortisol assay of choice uses high-pressure liquid chromatographic separation followed by mass spectrometric quantitation.23 With the use of this assay, the urinary free cortisol level in healthy adults ranges from 8 to 51 μg per 24 hours (mean [±SD], 23±8). Clinical depression increases urinary free cortisol excretion, and most studies show that the level of urinary free cortisol ranges from 10 to 60 μg per day in patients with typical clinical signs and symptoms of depression. If we use 60 μg per day as the cutoff between normal values (<60 μg per day) and elevated values (≥60 μg per day), urinary free cortisol excretion of 62 μg per day or more has a positive likelihood ratio of 11.24 Thus, in a patient presenting with obesity, hypertension, type 2 diabetes, and hirsutism who has thin skin, osteopenia, ecchymoses, and an elevated urinary free cortisol level, the probability of Cushing’s syndrome is 1 (100%). For such patients, the clinician should move directly to a differential diagnostic evaluation.

DEXAMETHASONE-SUPPRESSION TEST

The dexamethasone-suppression test is commonly used in the diagnosis of Cushing’s syndrome. This test was developed by Grant Liddle in the early 1960s as a differential diagnostic test to separate corticotropin-dependent from corticotropin-independent Cushing’s syndrome. This is now done by measuring the plasma corticotropin level. Unfortunately, dexamethasone suppression has continued to be used as a screening test for Cushing’s syndrome.

The control group for this test comprises patients with obesity and depression in whom cortisol secretion is not suppressed in response to an oral dose of 1 mg of dexamethasone at midnight. Of the current U.S. population of 360 million people, approximately one third (120 million people) are obese. Of those who are obese, 10% (12 million people) have depression. In half these patients (6 million people), the plasma cortisol level will not be suppressed in response to a dexamethasone challenge. On the basis of my estimate of the current prevalence of undiagnosed Cushing’s syndrome (24,000 cases) and the estimate of the at-risk population (6 million persons), the positive predictive value of the dexamethasone-suppression test is only 0.4%. Thus, this test should not influence what the physician does next and should no longer be used for this purpose.

OUTLIERS

For patients with convincing evidence of Cushing’s syndrome on physical examination and an elevated 24-hour urinary free cortisol level, the differential diagnostic process outlined below should be initiated. However, a small group of patients will not meet these criteria.

Some patients have a strongly positive physical examination but low or zero urinary free cortisol excretion. Plasma corticotropin levels are suppressed in these patients. These patients are receiving exogenous glucocorticoids. The glucocorticoid must be identified, and a plan must be made for its discontinuation. Sometimes the glucocorticoid is being given by proxy (e.g., by a parent to a child), and no history of glucocorticoid administration can be found. Nevertheless, the glucocorticoid must be identified and discontinued.

Other patients have few or no clinical signs of Cushing’s syndrome but do have elevated urinary free cortisol excretion. Plasma corticotropin is measurable in these patients. They are usually identified during an evaluation for arterial hypertension. All such patients should undergo inferior petrosal sinus sampling to determine the source of corticotropin secretion. Ectopic sources are almost always neoplastic and are usually in the chest.25 Patients with eutopic secretion usually have the syndrome of generalized glucocorticoid resistance.26

Finally, a few patients have convincing findings on physical examination coupled with a normal urinary free cortisol level. In such cases, the clinician should make sure that urinary free cortisol is being measured with high-performance liquid chromatography and mass spectrometry, that renal function is normal, and that the collections are complete. “Periodic” Cushing’s syndrome must be ruled out by measuring urinary free cortisol frequently over the course of a month.27 If these efforts fail, the patient should be followed for a year, with urinary free cortisol measurements performed frequently. No additional tests should be performed until the situation is sorted out. More tests would be likely to lead to an unnecessary surgical procedure.

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of Cushing’s syndrome is shown in Figure 3

FIGURE 3Differential Diagnosis of Cushing’s Syndrome.. If plasma corticotropin is measurable, the disease process is corticotropin-dependent. If corticotropin is not measurable, the process is corticotropin-independent.

Corticotropin-dependent causes of Cushing’s syndrome are divided into those in which the corticotropin comes from the pituitary (eutopic causes) and those in which the corticotropin comes from elsewhere (ectopic causes). This differentiation is made with the measurement of corticotropin in inferior petrosal sinus plasma and the simultaneous measurement of corticotropin in peripheral (antecubital) plasma immediately after corticotropin-releasing hormone stimulation of pituitary corticotropin secretion. In samples obtained 4, 6, and 15 minutes after stimulation with corticotropin-releasing hormone, eutopic corticotropin secretion is associated with a ratio of the central-plasma corticotropin level to the peripheral-plasma corticotropin level of 3 or more. Ectopic corticotropin secretion is associated with a central-to-peripheral corticotropin ratio of less than 3. The positive predictive value of this test is 1 (Figure 4

FIGURE 4Maximal Ratio of Corticotropin in Inferior Petrosal Sinus Plasma to Corticotropin in Peripheral Plasma in Patients with Cushing’s Syndrome, Ectopic Corticotropin Secretion, or Adrenal Disease.).28

Although some authorities suggest that inferior petrosal sinus sampling can safely be bypassed in patients with corticotropin-dependent Cushing’s syndrome and a well-defined pituitary adenoma, I disagree. The incidence of nonfunctioning pituitary microadenomas is between 15% and 40%.29 This means that up to 40% of patients with ectopic secretion of corticotropin have an incidental pituitary abnormality. If it is assumed that the pituitary abnormality is responsible for corticotropin secretion, 15 to 40% of patients with ectopic secretion of corticotropin will be misdiagnosed and submitted to a transsphenoidal exploration of the sella turcica and pituitary gland. The prevalence of ectopic corticotropin secretion in the population of patients with undiagnosed Cushing’s syndrome is about 10%, accounting for 2400 patients. Up to 40% of these patients, or 960, have an incidental pituitary tumor. The mortality associated with transsphenoidal microadenomectomy is 1%.30 If all 360 to 960 patients undergo this procedure, there will be up to 10 deaths from an operation that can have no benefit. For this reason alone, all patients with corticotropin-dependent Cushing’s syndrome should undergo inferior petrosal sinus sampling to confirm the source of corticotropin secretion before any surgical intervention is contemplated.

Patients with eutopic corticotropin secretion are almost certain to have a corticotropin-secreting pituitary microadenoma. An occasional patient will have alcohol-induced pseudo–Cushing’s syndrome. The slightest suggestion of alcoholism should lead to a 3-week abstinence period before any surgery is considered.31

Patients with ectopic corticotropin secretion are first evaluated with computed tomography (CT) or magnetic resonance imaging (MRI) of the chest. In two thirds of these patients, a tumor will be found.25 If nothing is found in the chest, MRI of the abdominal and pelvic organs is performed. If these additional imaging studies are also negative, there are two options: bilateral adrenalectomy or blockade of cortisol synthesis. If blockade is chosen, the patient should undergo repeat scanning at 6-month intervals.32 If no source is found by the end of the second year, it is unlikely that the source will ever be found, and bilateral adrenalectomy should be performed for definitive treatment (Doppman JL: personal communication).

Corticotropin-independent Cushing’s syndrome is usually caused by an adrenal neoplasm. Benign tumors tend to be small (<5 cm in diameter) and secrete a single hormone, cortisol. The contralateral adrenal gland is suppressed by the cortisol secreted from the tumorous gland. If the value for Hounsfield units is less than 10 and the washout of contrast material is greater than 60% at 15 minutes, the tumor is almost certainly benign.33 Such tumors can be treated successfully with laparoscopic adrenalectomy.

The syndromes of micronodular and macronodular adrenal dysplasia usually affect both adrenal glands. The nodules secrete cortisol. Corticotropin is suppressed, as is the internodular tissue of the adrenal glands. Percutaneous bilateral adrenalectomy, followed by glucocorticoid and mineralocorticoid treatment, is curative.

Adrenal tumors secreting more than one hormone (i.e., cortisol and androgen or estrogen) are almost always malignant. Surgical removal of all detectable disease is indicated, as is a careful search for metastases. If metastases are found, they should be removed. This usually requires an open adrenalectomy. It goes without saying that adrenal tumors, nodules, and metastases should be treated by the most experienced endocrine cancer surgeon available.

If the plasma cortisol level on the morning after a transsphenoidal microadenomectomy is 0, the operation was a success. The patient should be treated with oral hydrocortisone, at a dose of 12 mg per square meter of body-surface area once a day in the morning, and a tetracosactide (Cortrosyn) stimulation test should be performed at 3-month intervals. When the tetracosactide-stimulated plasma cortisol level is higher than 20 μg per deciliter (551 μmol per liter), cortisol administration can be stopped. The same rule applies in the case of a unilateral adrenalectomy. If the adrenalectomy is bilateral, cortisol, at a dose of 12 to 15 mg per square meter per day, and fludrocortisone (Florinef), at a dose of 100 μg per day, should be prescribed as lifelong therapy.

SUMMARY

The obesity epidemic has led to necessary changes in the evaluation and treatment of patients with Cushing’s syndrome. The most dramatic change is the emphasis on the antianabolic alterations in Cushing’s syndrome, which can provide a strong basis for separating patients with Cushing’s syndrome from the more numerous patients with obesity and the metabolic syndrome. More can be done along these lines. Likelihood ratios are known for proximal muscle weakness and can be known for brain atrophy and growth failure in children.

The dexamethasone-suppression test, although still very popular, no longer has a role in the evaluation and treatment of patients with Cushing’s syndrome. Only three biochemical tests are needed: urinary free cortisol, plasma corticotropin, and plasma cortisol measurements. Urinary free cortisol excretion is the test that confirms the clinical diagnosis of Cushing’s syndrome. To be trustworthy, it must be performed in the most stringent way, with the use of high-pressure liquid chromatography followed by mass spectrometric quantitation of cortisol. Measurement of plasma corticotropin is used to separate corticotropin-dependent from corticotropin-independent causes of Cushing’s syndrome and to separate eutopic from ectopic secretion of corticotropin. Inferior petrosal sinus sampling should be performed in all patients with corticotropin-dependent Cushing’s syndrome because of the high prevalence of nonfunctioning incidental pituitary adenomas among such patients. Measurement of plasma cortisol has only one use: determining the success or failure of transsphenoidal microadenomectomy or adrenalectomy. If the plasma cortisol level is not measurable on the morning after the operation (<5 μg per deciliter [138 μmol per liter]), the procedure was a success; if it is measurable, the operation failed. The surgeon must not administer intraoperative or postoperative synthetic glucocorticoids until the plasma cortisol level has been measured.

Successful evaluation of a patient who is suspected of having Cushing’s syndrome requires an endocrinologist who is skilled in physical diagnosis. Also required is a laboratory that measures urinary free cortisol using high-performance liquid chromatography and mass spectrometry and that can measure plasma cortisol and plasma corticotropin by means of radioimmunoassay.

Inferior petrosal sinus sampling is performed by an interventional radiologist. The treatment for all causes of Cushing’s syndrome, other than exogenous glucocorticoids, is surgical, and neurosurgeons, endocrine surgeons, and cancer surgeons are needed. This level of multidisciplinary medical expertise is usually found only at academic medical centers. Thus, most, if not all, patients with Cushing’s syndrome should be referred to such a center for treatment.

Disclosure forms provided by the author are available with the full text of this article at NEJM.org.

No potential conflict of interest relevant to this article was reported.

SOURCE INFORMATION

From the Division of Endocrinology, Diabetes, and Clinical Nutrition, Oregon Health and Science University, Portland.

Address reprint requests to Dr. Loriaux at the Division of Endocrinology, Diabetes, and Clinical Nutrition, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., L607, Portland, OR 97239-3098, or at .

From http://www.nejm.org/doi/full/10.1056/NEJMra1505550

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FDA Declines to Approve Relacorilant for Hypertension Linked to Hypercortisolism

Posted on January 6, 2026 by MaryO

Key takeaways:

  • The FDA issued a complete response letter for relacorilant to treat hypertension tied to hypercortisolism.
  • The investigational drug induced BP reductions for adults with hypertension in the phase 3 GRACE trial.

The FDA has issued a complete response letter for an oral selective glucocorticoid receptor antagonist under investigation for the treatment of hypertension secondary to hypercortisolism, according to an industry press release.

Corcept Therapeutics announced the FDA issued a complete response letter for relacorilant (Corcept Therapeutics). The drug is under investigation for the treatment of endogenous hypercortisolism, ovarian cancer and other disorders, according to the company.

As Healio previously reported, the phase 3 GRACE trial enrolled 152 adults with Cushing’s syndrome plus hypertension, hyperglycemia or both conditions. Participants received relacorilant for 22 weeks during an open-label phase. At 22 weeks, adults who met criteria for hypertension or hyperglycemia control entered a withdrawal phase where they were randomly assigned, 1:1, to continue relacorilant or switch to placebo for 12 weeks.

In the GRACE trial, adults with hypertension had a 7.9 mm Hg decrease in systolic blood pressure and a 5.1 mm Hg decline in diastolic BP at 22 weeks. During the randomized withdrawal phase, adults who remained on relacorilant had no change in systolic and diastolic BP, whereas those receiving placebo had a BP increase from the start of the phase to week 12.

In a press release from Corcept Therapeutics from 2024, the company announced results from the phase 3 GRADIENT trial, a randomized, double-blind, placebo-controlled trial where adults with Cushing’s syndrome caused by an adrenal adenoma or adrenal hyperplasia were randomly assigned, 1:1, to relacorilant or placebo for 22 weeks. According to the press release, the relacorilant group had a 6.6 mm Hg decline in mean systolic BP compared with baseline at 22 weeks. However, there was no significant difference in mean systolic BP change between the relacorilant and placebo groups.

As Healio previously reported, relacorilant was also assessed in a long-term extension study that enrolled adults who completed the GRACE and GRADIENT trials as well as a phase 2 hypercortisolism study. In that trial, relacorilant conferred a 10 mm Hg drop in 24-hour ambulatory systolic BP and a 7.3 mm Hg reduction in 24-hour ambulatory diastolic BP at 24 months.

In the company’s press release announcing receipt of the complete response letter, Corcept Therapeutics said the FDA acknowledged that the GRACE trial met its primary endpoint and that the GRADIENT trial provided “confirmatory evidence.” However, the FDA said it did not view relacorilant offered “a favorable benefit-risk assessment” without more data of its effectiveness, according to the press release.

“We are surprised and disappointed by this outcome,” Joseph K. Belanoff, MD, CEO of Corcept Therapeutics, said in a press release. “Our commitment to patients suffering from the effects of hypercortisolism is unwavering. I am confident we will find a way to get relacorilant to the patients it could help. We will meet with the FDA as soon as possible to discuss the best path forward.”

https://www.healio.com/news/endocrinology/20251231/fda-declines-to-approve-relacorilant-for-hypertension-linked-to-hypercortisolism?utm_source=selligent&utm_medium=email&utm_campaign=20251231ENDO&utm_content=20251231ENDO

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