Characterization of persistent and recurrent Cushing’s disease

Pituitary, 09/25/2013  Review Article

Sundaram NK et al. – A case of possible recurrent Cushing’s disease (CD) is presented and data on current definitions of CD remission, persistence, and recurrence are reviewed.

The number and degree of abnormal test results needed to define recurrence, and the determination of which biochemical test has more significance when there are discrepancies between markers is inconsistent among studies. Further inquiry is warranted to examine if patients in apparent CD remission who have subtle hypothalamic pituitary adrenal (HPA) axis abnormalities represent distinctive remission subtypes versus mild or early recurrence.

Additional investigation could also explore the degree to which these HPA axis abnormalities, such as alterations in cortisol circadian rhythm or partial resistance to dexamethasone, are associated with persistence of CD morbidities, including neuropsychiatric impairments, alterations in body composition, and cardiovascular risk.

From MDLinx

Mifepristone in children with refractory Cushing’s disease

Introduction

This study is being done to examine the effects of a medication called mifepristone in children with Cushing’s disease. This medication has been approved by the Food and Drug Administration (FDA) for use in adult patients with Cushing’s syndrome. It is not FDA approved for use in children.

The study will investigate how children’s bodies absorb and process mifepristone, how it works in children and what effect it has on the use of sugar in the body, on the child’s weight and on growth hormone. An important part of the study is to determine the proper dosing and to evaluate the side effects of mifepristone in children.

Children 6 to 17 years old will be enrolled in the study if they have had surgery for Cushing’s disease and currently have elevated cortisol levels.

To get started, please click here.

Enzyme linked to obesity

Researchers find that increased levels of an enzyme in fat cells lead to dangerous levels of abdominal obesity.

Previous studies have shown that the stress hormone cortisol can lead to an accumulation of fat round the abdomen. For instance, people with Cushing’s disease – where there’s excess cortisol in the blood – have too much abdominal fat. It’s bad for health to have fat in this area – it’s linked to diabetes and heart disease. That’s why it’s healthier to be a ‘pear shape’ rather than an ‘apple shape’. The distribution of fat in your body really does matter.

Researchers in Scotland and the US have now focussed upon an enzyme that produces cortisol to see what effect it has on abdominal fat. Working on mice genetically-modified to produce the enzyme – and therefore cortisol – in fat cells, they find that even a small increase in levels produces dramatic effects. The mice, compared with normal animals, gained fat in the abdominal area even on a low fat diet. They developed diabetes, high blood pressure, and also tended to eat more. It opens up the possibility of further studies on human obesity, and also perhaps could lead to therapies that block this enzyme and so reduce fat accumulation.

From http://www.tele-management.ca/2013/09/enzyme-linked-to-obesity/

Differences Between Cushing’s Syndrome and Cushing’s Disease

What’s the difference between Cushing’s Disease and Cushing’s Syndrome?

disease-syndrome

Cushing’s syndrome is a hormonal disorder

Cortisol is a normal hormone produced in the outer portion of the adrenal glands. When functioning normally, cortisol helps the body respond to stress and change. It mobilizes nutrients, modifies the body’s response to inflammation, stimulates the liver to raise blood sugar, and helps control the amount of water in the body. Cortisol production is regulated by the adrenocorticotrophic hormone (ACTH), produced in the pituitary gland. Spontaneous overproduction of cortisol in the adrenals is divided into two groups – those attributed to an excess of ACTH and those that are independent of ACTH.

Cushing’s syndrome is the term used to describe a group of symptoms that occur when a persons’ cortisol levels are too high (known as hypercortisolism) for too long. The majority of people have Cushing’s syndrome because they are regularly taking certain medicine(s) that continually add too much cortisol to the body. Doctors call this an “exogenous” (outside the body) cause of Cushing’s syndrome. Other people have Cushing’s syndrome because something is causing the adrenal gland(s) to overproduce cortisol. Doctors call this an “endogenous” (inside the body) cause of Cushing’s syndrome.

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Cushing’s disease is a form of Cushing’s syndrome

Cushing’s disease is the most common form of endogenous Cushing’s syndrome. It is caused by a tumor in the pituitary gland that secretes excessive amounts of a hormone called Adrenocorticotropic hormone, or ACTH. Fortunately, this type of tumor is typically benign. Unlike a cancerous (malignant) tumor, a benign tumor stays in its original location and will not spread. After you are diagnosed with Cushing’s syndrome, it is important that your doctor continues the diagnostic process to determine the cause of hypercortisolism.

From the message boards It is not only a tumor that causes Cushings Disease—many of us have the rarer form of this rare disease which is Pituitary Hyperplasia. It also causes CD and may be nodular (shown on MRI s a tumor) or dispersed (meaning spread throughout the gland).

How a pituitary tumor causes Cushing’s disease

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ACTH is a hormone produced in your pituitary gland. ACTH travels to your adrenal glands and signals them to produce cortisol.

Pituitary adenomas are benign tumors of the pituitary gland which secrete increased amounts of ACTH, causing excessive cortisol production. Most patients have a single adenoma. First described in 1912 by neurosurgeon Harvey Cushing in his book The Pituitary Body and its Disorders, Cushing’s disease is the most common cause of spontaneous Cushing’s syndrome, accounting for 60 to 70 percent of cases.

If a person has Cushing’s disease, it means that a group of abnormal cells has built up in the pituitary gland to form an ACTH-producing pituitary tumor. These abnormal cells produce ACTH, just as normal pituitary gland cells do—only far too much. The excess ACTH travels to adrenal glands. The adrenal glands are then bombarded with signals to produce more and more cortisol. As a result, the adrenal glands continuously secrete too much cortisol.

Ectopic ACTH Syndrome

Some benign or malignant (cancerous) tumors that arise outside the pituitary can produce ACTH. This condition is known as ectopic ACTH syndrome. Lung tumors cause more than 50 percent of these cases. Other less common types of tumors that can produce ACTH are thymomas, pancreatic islet cell tumors, and medullary carcinomas of the thyroid.

Adrenal Tumors

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An abnormality of the adrenal glands such as an adrenal tumor may cause Cushing’s syndrome. Most of these cases involve non-cancerous tumors called adrenal adenomas, which release excess cortisol into the blood.

Adrenocortical carcinomas, or adrenal cancers, are the least common cause of Cushing’s syndrome. Cancer cells secrete excess levels of several adrenal cortical hormones, including cortisol and adrenal androgens. Adrenocortical carcinomas often cause very high hormone levels and rapid onset of symptoms.

Familial Cushing’s syndrome

Most cases of Cushing’s syndrome are not genetic. However, some individuals may develop Cushing’s syndrome due to an inherited tendency to develop tumors of one or more endocrine glands. In Primary Pigmented Micronodular Adrenal Disease, children or young adults develop small cortisol-producing tumors of the adrenal glands. In Multiple Endocrine Neoplasia Type I (MEN I), hormone secreting tumors of the parathyroid glands, pancreas and pituitary occur. Cushing’s syndrome in MEN I may be due to pituitary, ectopic or adrenal tumors.

Risk factors

Obesity, type 2 diabetes, poorly controlled blood glucose (blood sugar levels), and high blood pressure may increase the risk of developing this disorder.

Adapted from http://www.cushiewiki.com/index.php?title=Cushing%27s_Disease_or_Syndrome

Cyclic Cushing’s syndrome: a clinical challenge

  1. J R Meinardi1,2,
  2. B H R Wolffenbuttel2 and
  3. R P F Dullaart2

+Author Affiliations


  1. 1Department of Internal Medicine, Canisius Wilhelmina Ziekenhuis, PO Box 9015, 6500 GS Nijmegen, The Netherlands and 2Department of Endocrinology, University Medical Centre Groningen, University of Groningen, PO Box 30001, 9700 RB Groningen, The Netherlands
  1. (Correspondence should be addressed to: R P F Dullaart; Email:r.p.f.dullaart@int.umcg.nl)

Abstract

Cyclic Cushing’s syndrome (CS) is a rare disorder, characterized by repeated episodes of cortisol excess interspersed by periods of normal cortisol secretion. The so-called cycles of hypercortisolism can occur regularly or irregularly with intercyclic phases ranging from days to years.

To formally diagnose cyclic CS, three peaks and two troughs of cortisol production should be demonstrated. Our review of 65 reported cases demonstrates that cyclic CS originates in 54% of cases from a pituitary corticotroph adenoma, in 26% from an ectopic ACTH-producing tumour and in about 11% from an adrenal tumour, the remainder being unclassified. The pathophysiology of cyclic CS is largely unknown.

The majority of patients with cyclic CS have clinical signs of CS, which can be either fluctuating or permanent. In a minority of patients, clinical signs of CS are absent. The fluctuating clinical picture and discrepant biochemical findings make cyclic CS extremely hard to diagnose. Clinicians should therefore be aware of this clinical entity and actively search for it in all patients with suspected CS but normal biochemistry or vice versa.

Frequent measurements of urinary cortisol or salivary cortisol levels are a reliable and convenient screening tool for suspected cyclic CS. Cortisol stimulation or suppression tests may give spurious results owing to spontaneous falls or rises in serum cortisol at the time of testing. When cyclic CS is biochemically confirmed, further imaging and laboratory studies are guided by the presence or absence of ACTH dependency. In cases of suspected ectopic ACTH production, specific biochemical testing for carcinoids or neuroendocrine tumours is required, including measurements of serotonin in platelets and/or urine, chromogranin A and calcitonin.

Read the entire article here:  http://www.scribd.com/doc/159503297/Cyclic-Cushing%E2%80%99s-syndrome-a-clinical-challenge