How to avoid pitfalls in interpretation of adrenal imaging

By Philip Ward, AuntMinnieEurope.com staff writer

January 15, 2019 — A clear understanding of the pitfalls in the performance and interpretation of adrenal CT can help prevent incorrect and inappropriate investigations, award-winning researchers from a top London facility have found. It’s essential to keep aware of the full range of pseudolesions and mimics, they said.

“Evaluation of adrenal tumor function is limited on imaging, but may be inferred from imaging findings,” noted Dr. Gurinder Nandra and colleagues from the department of radiology at St. George’s University Hospitals NHS Foundation Trust in an e-poster presentation that received a cum laude award at RSNA 2018 in Chicago.

Other adrenal pathology, including metastases and adrenocortical carcinoma, may be encountered, and this means it’s important to know about the imaging approaches to evaluate the adrenals, the authors pointed out.

Incidental adrenal nodules are identified in around 5% of patients who undergo CT. The prevalence of detecting incidentalomas increases with age, but most incidentally encountered adrenal pathology is benign and of little clinical relevance, they wrote. Adenomas are by far the most common adrenal pathology identified.

Among the technical aspects that deserve special attention are the following:

  • The region of interest (ROI): Changing the size of the ROI can alter the perceived attenuation of the nodule. The ROI should cover at least two-thirds of the circumference of the nodule, and exclude tiny areas of heterogeneity from the ROI (e.g., flecks of calcification) that are not representative of the adrenal pathology. Unenhanced attenuation of less than 10 Hounsfield units (HU) can be used to diagnose lipid-rich adrenal adenoma (sensitivity 71%, specificity of 98%).
  • Attenuation values on unenhanced CT: A homogenously dense lesion on unenhanced CT suggests a lack of microscopic lipid content. If attenuation on unenhanced CT is greater than 20 to 30 HU, evaluate the enhancement kinetics with CT.
  • Effect of kVp on attenuation values in a dual energy study: To use threshold of less than 10 HU to diagnose a lipid-rich adrenal adenoma, the kVp should be 120. Changing kVp can alter the attenuation values of soft tissues and adrenal glands.
  • Timing of post-contrast acquisitions: “Imaging needs to be performed at the correct times to allow sufficient time for enhancement and washout of contrast. Post-contrast images should be obtained at 60 to 75 seconds and 15 minutes,” the authors stated.
  • Assessment of washout on nondedicated studies: Relative washout can be calculated on nondedicated studies if more than one acquisition is made within 15 minutes post-intravenous contrast.
  • Suspicious attenuation: Attenuation of more than 43 HU on noncontrast CT is suspicious for malignancy, regardless of washout characteristics. PET/CT is of more use than CT and MRI in such cases, and adrenal hemorrhage also is a consideration at this attenuation.
  • Evaluation of small nodules: Minor nodularity of less than 1 cm in diameter does not require further radiological investigation. Also, CT evaluation of small adrenal nodules is limited by partial volume artifacts. MRI evaluation of small adrenal nodules is limited by the India ink artifact, or black boundary artifact, on an out-of-phase sequence. This artifact may give the impression of signal loss and lead to an incorrect diagnosis of a lipid-rich adenoma.
  • Evaluation of large adrenal masses: Malignancy risk increases with size (over 4 cm, 70%; over 6 cm, 85%) when excluding myelolipoma. In the absence of known malignancy, an adrenal lesion of less than 4 cm with indeterminate imaging features is likely to be benign.
  • Enhancement characteristics of metastases: Enhancement/washout characteristics of adrenal metastases are variable, and they can be confused with pheochromocytoma.
  • Adrenal calcification: Calcification is seen in benign adrenal pathology, but also can be seen in cases of malignancy, including adrenocortical carcinoma. “Look for ancillary features of malignancy including size, heterogeneity and invasion,” the authors recommended. “Evaluation of a predominantly calcified adrenal lesion will be limited with chemical shift MRI.”
  • Heterogeneous signal loss: Heterogeneous signal loss is not typical for a small lipid-rich adenoma and raises the possibility of malignant pathology. It also can be seen in larger adenomas because of calcification/cystic change/myelolipomatous metaplasia.

In their RSNA 2018 exhibit, Nandra and colleagues also identified the following list of mimics that can crop up:

  • Mimics arising from gastrointestinal tract: Gastric pathology can extend into the left suprarenal space and mimic adrenal pathology. The most common mimics include gastrointestinal stromal tumors and gastric diverticula. Pathology elsewhere in the gastrointestinal tract can mimic adrenal pathology (e.g., a fluid-filled colon).
  • Mimics arising from solid viscera: Pathology from the spleen, pancreas, liver, and kidneys can extend into the suprarenal space and mimic adrenal pathology. This includes splenic lobulation, splenunculi, upper pole renal pathology, pancreatic tail pathology, and exophytic hepatic lesions.
  • Mimics arising from vessels: Dilated, tortuous, or aneurysmal vessels may extend into the suprarenal space and mimic adrenal pathology. The most common mimics include splenic varices and splenic artery pseudoaneurysms.
  • Mimics arising from retroperitoneal tissues: Various retroperitoneal lesions can extend into the suprarenal space and mimic adrenal pathology, and normal anatomy in the retroperitoneum also can mimic adrenal pathology (e.g., a thickened diaphragmatic crus).

From https://www.auntminnieeurope.com/index.aspx?sec=ser&sub=def&pag=dis&ItemID=616803

CV risk elevated in patients with adrenal incidentalomas, mild hypercortisolism

Patients with adrenal incidentalomas and mild hypercortisolism have an increased risk for cardiovascular events and mortality. This risk was evident even when clinical signs of overt hypercortisolism were not present, according to data published in The Lancet Diabetes & Endocrinology.

“Our findings are important because they add to the previously scant information about adrenal incidentalomas, which will be of use to doctors who are seeing an increasing number of patients with these masses,” Renato Pasquali, MD, of the S. Orsola-Malpighi Hospital in Bologna, Italy, said in a press release.

The retrospective study by Pasquali and colleagues assessed the adrenal incidentalomas of 198 outpatients treated every 18 to 30 months, with a mean follow-up of 7.5 years. At the time of follow-up, 114 patients demonstrated stable non-secreting adrenal incidentalomas (<50 nmol/L), 61 had either a stable intermediate phenotype (50 nmol/L-138 nmol/L) or subclinical Cushing’s syndrome (>138 nmol/L), and 23 patients had worsening pattern of secretion.

The incidence of CV events appeared higher in patients with a stable intermediate phenotype or subclinical Cushing’s syndrome (6.7% vs. 16.7%; P=.04) and in those with worsened secreting patterns (6.7% vs. 28.4%; P=.02) compared with patients with stable non-secreting adrenal incidentalomas, according to data.

In addition, CV events were independently related to changes in cortisol concentrations after the 1-mg dexamethasone suppression test (DST; HR=1.13; 95% CI, 1.05-1.21) from baseline to follow-up.

Patients with stable intermediate phenotype adrenal incidentalomas (57%) or subclinical Cushing’s syndrome (91.2%) tended to have lower survival rates for all-cause mortality (P=.005), researchers wrote. The main risk factors for all-cause mortality were age (HR=1.06; 95% CI, 1.01-1.12) and mean concentrations of cortisol after DST (HR=1.1; 95% CI, 1.01-1.19).

The unadjusted survival for CV-related mortality was lower in patients with either a stable intermediate phenotype (97.5%) or subclinical Cushing’s syndrome (78.4%; P=.02) vs. those with stable non-secreting adrenal incidentalomas (97.5%), and patients with worsened secreting patterns (60%; P=.01).

In an accompanying comment, Rosario Pivonello, MD, PhD, Maria Cristina De Martino, PhD, and Annamaria Colao, MD, PhD, of the Federico II University of Naples, Italy, wrote that the study supports the importance of long-term hormonal follow-up for clinical management of patients with adrenal incidentalomas.

“Furthermore, clinical monitoring of cardiometabolic risks seems to be important in these patients, particularly in those with subclinical Cushing’s syndrome and intermediate phenotype adrenal incidentalomas, for whom medical or surgical intervention could be needed,” they wrote.

They suggest long-term prospective studies to determine the frequency of new CV events and mortality in this patient population.

For more information:

Di Dalmazi G. Lancet Diabetes Endocrinol. 2014;doi:10.1016/S2213-8587(13)70211-0.

Pivonello R. Lancet Diabetes Endocrinol. 2014;doi:10.1016/S2213-8587(13)70190-6.

Disclosure: The researchers report no relevant financial disclosures.

This article is from http://www.healio.com/endocrinology/adrenal/news/online/%7B85f94352-9529-4cb7-9532-9c4518f77d80%7D/cv-risk-elevated-in-patients-with-adrenal-incidentalomas-mild-hypercortisolism

 

Adrenal Diseases During Pregnancy: Pathophysiology, Diagnosis And Management Strategies

Am J Med Sci. 2014 Jan;347(1):64-73. doi: 10.1097/MAJ.0b013e31828aaeee.

Author information

Abstract

: Adrenal diseases-including disorders such as Cushing’s syndrome, Addison’s disease, pheochromocytoma, primary hyperaldosteronism and congenital adrenal hyperplasia-are relatively rare in pregnancy, but a timely diagnosis and proper treatment are critical because these disorders can cause maternal and fetal morbidity and mortality.

Making the diagnosis of adrenal disorders in pregnancy is challenging as symptoms associated with pregnancy are also seen in adrenal diseases. In addition, pregnancy is marked by several endocrine changes, including activation of the renin-angiotensin-aldosterone system and the hypothalamic-pituitary-adrenal axis.

The aim of this article was to review the pathophysiology, clinical manifestation, diagnosis and management of various adrenal disorders during pregnancy.

PMID:
23514671
[PubMed – in process]

From http://www.ncbi.nlm.nih.gov/pubmed/23514671

Think Like a Doctor: Red Herrings Solved!

By LISA SANDERS, M.D.

On Thursday we challenged Well readers to take the case of a 29-year-old woman with an injured groin, a swollen foot and other abnormalities. Many of you found it as challenging as the doctors who saw her. I asked for the right test as well as the right diagnosis. More than 200 answers were posted.

The right test was…

The dexamethasone suppression test,though I counted those of you who suggested measuring the cortisol in the urine.

The right diagnosis was…

Cushing’s disease

More than a dozen of you got the right answer or the right test, but Dr. Davin Quinn, a consultant psychiatrist at the University of New Mexico Hospital, was the first to be right on both counts. As soon as he saw that the patient’s cortisol level was increased, he thought of Cushing’s. And he had treated a young patient like this one some years ago as a second year resident.

The Diagnosis:

Cushing’s disease is caused by having too much of the stress hormone cortisol in the body. Cortisol is made in the adrenal glands, little pyramid shaped organs that sit atop the kidneys. It is normally a very tightly regulated hormone that helps the body respond to physical stress.

Sometimes the excess comes from a tumor in the adrenal gland itself that causes the little organ to go into overdrive, making too much cortisol. More often the excess occurs when a tumor in the pituitary gland in the brain results in too much ACTH, the hormone that controls the adrenal gland.

In the body, cortisol’s most fundamental job is to make sure we have enough glucose around to get the body’s work done. To that end, the hormone drives appetite, so that enough fuel is taken in through the food we eat. When needed, it can break muscle down into glucose. This essential function accounts for the most common symptoms of cortisol excess: hyperglycemia, weight gain and muscle wasting. However, cortisol has many functions in the body, and so an excess of the hormone can manifest itself in many different ways.

Cushing’s was first described by Dr. Harvey Cushing, a surgeon often considered the father of modern neurosurgery. In a case report in 1912, he described a 23-year-old woman with sudden weight gain, mostly in the abdomen; stretch marks from skin too thin and delicate to accommodate the excess girth; easy bruising; high blood pressure and diabetes.

Dr. Cushing’s case was, it turns out, a classic presentation of the illness. It wasn’t until 20 years later that he recognized that the disease had two forms. When it is a primary problem of an adrenal gland gone wild and producing too much cortisol on its own, the disease is known as Cushing’s syndrome. When the problem results from an overgrown part of the pituitary making too much ACTH and causing the completely normal adrenal glands to overproduce the hormone, the illness is called Cushing’s disease.

It was an important distinction, since the treatment often requires a surgical resection of the body part where the problem originates. Cushing’s syndrome can also be caused by steroid-containing medications, which are frequently used to treat certain pulmonary and autoimmune diseases.

How the Diagnosis Was Made:

After the young woman got her lab results from Dr. Becky Miller, the hematologist she had been referred to after seeing several other specialists, the patient started reading up on the abnormalities that had been found. And based on what she found on the Internet, she had an idea of what was going on with her body.

“I think I have Cushing’s disease,” the patient told her endocrinologist when she saw him again a few weeks later.

The patient laid out her argument. In Cushing’s, the body puts out too much cortisol, one of the fight-or-flight stress hormones. That would explain her high blood pressure. Just about everyone with Cushing’s disease has high blood pressure.

She had other symptoms of Cushing’s, too. She bruised easily. And she’d been waking up crazy early in the morning for the past year or so – around 4:30 – and couldn’t get back to sleep. She’d heard that too much cortisol could cause that as well. She was losing muscle mass – she used to have well-defined muscles in her thighs and calves. Not any more. Her belly – it wasn’t huge, but it was a lot bigger than it had been. Cushing’s seemed the obvious diagnosis.

The doctor was skeptical. He had seen Cushing’s before, and this patient didn’t match the typical pattern. She was the right age for Cushing’s and she had high blood pressure, but nothing else seemed to fit. She wasn’t obese. Indeed, she was tall (5- foot-10) and slim (150 pounds) and athletic looking. She didn’t have stretch marks; she didn’t have diabetes. She said she bruised easily, but the endocrinologist saw no bruises on exam. Her ankle was still swollen, and Cushing’s can do that, but so can lots of other diseases.

The blood tests that Dr. Miller ordered measuring the patient’s ACTH and cortisol levels were suggestive of the disease, but many common problems — depression, alcohol use, eating disorders — can cause the same result. Still, it was worth taking the next step: a dexamethasone suppression test.

Testing, Then Treatment:

The dexamethasone suppression test depends on a natural negative feedback loop whereby high levels of cortisol suppress further secretion of the hormone. Dexamethasone is an artificial form of cortisol. Given in high doses, it will cause the level of naturally-occurring cortisol to drop dramatically.

The patient was told to take the dexamethasone pills the night before having her blood tested. The doctor called her the next day.

“Are you sure you took the pills I gave you last night?” the endocrinologist asked her over the phone. The doctor’s voice sounded a little sharp to the young woman, tinged with a hint of accusation.

“Of course I took them,” she responded, trying to keep her voice clear of any irritation.

“Well, the results are crazy,” he told her and proposed she take another test: a 24-hour urine test.

Because cortisol is eliminated through the kidneys, collecting a full day’s urine would show how much cortisol her body was making. So the patient carefully collected a day’s worth of urine.

A few days later, the endocrinologist called again: her cortisol level was shockingly high. She was right, the doctor conceded, she really did have Cushing’s.

An M.R.I. scan revealed a tiny tumor on her pituitary. A couple of months later, she had surgery to remove the affected part of the gland.

After recovering from the surgery, the patient’s blood pressure returned to normal, as did her red blood cell count and her persistently swollen ankle. And she was able to once again sleep through the night.

Red Herrings Everywhere:

As many readers noted, there were lots of findings that didn’t really add up in this case. Was this woman’s groin sprain part of the Cushing’s? What about the lower extremity swelling, and the excess red blood cell count?

In the medical literature, there is a single case report of high red blood cell counts as the presenting symptom in a patient with Cushing’s. And with this patient, the problem resolved after her surgery – so maybe they were linked.

And what about the weird bone marrow biopsy? The gastritis? The enlarged spleen? It’s hard to say for certain if any of these problems was a result of the excess cortisol or if she just happened to have other medical problems.

Why the patient didn’t have the typical symptoms of Cushing’s is easier to explain. She was very early in the course of the disease when she got her diagnosis. Most patients are diagnosed once symptoms have become more prominent

By the time this patient had her surgery, a couple of months later, the round face and belly characteristic of cortisol excess were present. Now, two years after her surgery, none of the symptoms remain.

From http://well.blogs.nytimes.com/2014/01/17/think-like-a-doctor-red-herrings-solved/?_php=true&_type=blogs&_r=0

Cushing Patients Could Be Diagnosed, Subtyped Using Plasma Steroid Levels

Patients with different subtypes of Cushing’s syndrome (CS) have distinct plasma steroid profiles. This could be used as a test for diagnosis and classification, a German study says.

The study, “Plasma Steroid Metabolome for Diagnosis and Subtyping Patients with Cushing Syndrome,” appeared in the journal Clinical Chemistry.

A quick diagnosis of CS is crucial so that doctors can promptly give therapy. However, diagnosing CS is often complicated by the multiple tests necessary not just to diagnose the disease but also to determine its particular subtype.

Cortisol, which leads to CS when produced at high levels, is a steroid hormone. But while earlier studies were conducted to determine whether patients with different subtypes of CS had distinct steroid profiles, the methods researchers used were cumbersome and have been discontinued for routine use.

Recently, a technique called LC-MS/MS has emerged for multi-steroid profiling in patients with adrenocortical dysfunction such as congenital adrenal hyperplasia, adrenal insufficiency and primary aldosteronism.

Researchers at Germany’s Technische Universität in Dresden used that method to determine whether patients with the three main subtypes of CS (pituitary, ectopic and adrenal) showed differences in plasma steroid profiles. They measured levels of 15 steroids produced by the adrenal glands in single plasma samples collected from 84 patients with confirmed CS and 227 age-matched controls.

They found that CS patients saw huge increases in the plasma steroid levels of 11-deoxycortisol (289%), 21-deoxycortisol (150%), 11-deoxycorticosterone (133%), corticosterone (124%) and cortisol (122%), compared to patients without the disease.

Patients with the ectopic subtype had the biggest jumps in levels of these steroids. However, plasma 18-oxocortisol levels were particularly low in ectopic disease. Other steroids demonstrated considerable variation.

Patients with the adrenal subtype had the lowest concentration of dehydroepiandrosterone (DHEA) and DHEA-SO4, which are androgens. Patients with the ectopic and pituitary subtype had the lowest concentration of aldosterone.

Through the use of 10 selected steroids, patients with different subtypes of CS could be identified almost as closely as with other tests, including the salivary and urinary free cortisol test, the dexamethasone-suppressed cortisol test, and plasma adrenocorticotropin levels. The misclassification rate using steroid levels was 9.5 percent, compared to 5.8 percent in other tests.

“This study using simultaneous LC-MS/MS measurements of 15 adrenal steroids in plasma establishes distinct steroid metabolome profiles that might be useful as a test for CS,” the team concluded, adding that using LC-MS/MS is advantageous, as specimen preparation is simple and the entire panel takes 12 minutes to run. This means it could be offered as a single test for both identification and subtype classification.

From https://cushingsdiseasenews.com/2018/01/02/plasma-steroid-levels-used-screen-diagnosis-subtyping-patients-cushing-syndrome/