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

Bio Categories

Chemical structure of cortisol.

Chemical structure of cortisol. (Photo credit: Wikipedia)

List of all the categories from Cushing’s Bios

Mortality in Cushing’s syndrome: data from 386 patients from a single tertiary referral center

Source

M Yaneva, Endocrinology, Medical University, Sofia, 1341, Bulgaria.

European Journal of Endocrinology, 08/16/2013  Review Article

Yaneva MK et al. – Data on the incidence, mortality and causes of death in patients with Cushing’s syndrome (CS) are scarce, due to the rarity of CS. The aim of the study was to analyze mortality rates in CS in a large cohort of patients of all etiologies and to determine the cause of death. Patients with CS have increased mortality due to vascular events and infections.

Abstract

OBJECTIVE:

Data on the incidence, mortality and causes of death in patients with Cushing’s syndrome (CS) are scarce, due to the rarity of CS. The aim of the study was to analyze mortality rates in CS in a large cohort of patients of all etiologies and to determine the cause of death.

DESIGN:

This was a retrospective study of patients with CS, treated over a period of 45 years in the main tertiary referral center in Bulgaria.

METHODS:

386 patients with CS of all etiologies were included. The main outcome measures were the standardized mortality ratio (SMR) and the cause of death.

RESULTS:

Mean (± SD) age at diagnosis was 38±13 years; 84% of patients were women; mean follow up was 85 months (range: 0-494 months). The SMR in the CS cohort was 4.05 (95% confidence interval (CI) 2.50-5.80) (p<0.0001). The following subgroups did not have a significantly increased SMR: patients with Cushing’s disease SMR – 1.88 (95%CI 0.69-4.08), adrenal adenomas 1.67 (95%CI 0.20-6.02) and ACTH-independent bilateral adrenal hyperplasia 1.14 (95 %CI 0.21-6.34). Patients with adrenal carcinomas, ectopic CS and those with CS of undetermined etiology had significantly increased SMR: 48.00 (95%CI 30.75-71.42), 13.33 (95%CI 0.00-24.59) and 4.00 (95%CI 0.48-14.45), respectively (p<0.0001). The significant predictors for mortality were active disease at death, age, male sex, etiology of the disease, the overall duration of active disease. The major causes of death were vascular events (40%) -cardiovascular 29% and cerebrovascular 11%, followed by infections (12%).

CONCLUSIONS:

Patients with CS have increased mortality due to vascular events and infections.

Read more at MDLinx

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

Prolactin Measure Didn’t Help Localize Pituitary Adenoma

By: SHERRY BOSCHERT, Clinical Endocrinology News Digital Network

SAN FRANCISCO – Measurements of prolactin levels during inferior petrosal sinus sampling did not help localize pituitary adenomas in patients with Cushing’s disease in a study of 28 patients, contradicting findings from a previous study of 28 patients.

The value of prolactin measurements in tumor localization using inferior petrosal sinus sampling (IPSS) remains unclear and needs further study in a larger, prospective study, Dr. Susmeeta T. Sharma said at the Endocrine Society’s Annual Meeting. The current and previous studies were retrospective analyses.

Although IPSS has been considered the standard test in patients with ACTH-dependent Cushing’s syndrome to differentiate between ectopic ACTH secretion and Cushing’s disease, there has been controversy about its value in localizing adenomas within the pituitary gland once a biochemical diagnosis of Cushing’s disease has been made. Various studies that used an intersinus ACTH ratio of 1.4 or greater before or after corticotropin-releasing hormone (CRH) stimulation have reported success rates as low as 50% and as high as 100% for tumor location.

A previous retrospective study of 28 patients with Cushing’s disease reported that adjusting the ACTH intersinus gradient by levels of prolactin before or after CRH stimulation, and combining the prolactin-adjusted ACTH intersinus ratio, improved pituitary adenoma localization. Magnetic resonance imaging (MRI) alone correctly localized the pituitary adenoma in 17 patients (61%), a prolactin-adjusted ACTH intersinus ratio of at least 1.4 improved the localization rate to 21 patients (75%), and combining MRI and the prolactin-adjusted ACTH intersinus ratio improved localization further to 23 patients, or 82% (Clin. Endocrinol. 2012;77:268-74).

The findings inspired the current retrospective study. The investigators looked at prolactin levels measured in stored petrosal and peripheral venous samples at baseline and at the time of peak ACTH levels after CRH stimulation for 28 patients with Cushing’s disease and ACTH-positive pituitary adenomas who underwent IPSS in 2007-2013. The investigators calculated prolactin-adjusted values by dividing each ACTH value by the concomitant ipsilateral prolactin value. They used an intersinus ACTH ratio of 1.4 or greater to predict tumor location.

At surgery, 26 patients had a single lateral tumor (meaning its epicenter was not in the midline), 1 patient had a central microadenoma, and 1 patient had a macroadenoma, reported Dr. Sharma of the National Institute of Child Health and Human Development, Bethesda, Md.

MRI findings accurately identified the location of 21 of the 26 lateral tumors (81%), compared with accurate localization in 18 patients using either the unadjusted ACTH intersinus ratio or the prolactin-adjusted ACTH intersinus ratio (69% for each), she said.

Incorrect tumor localization occurred with one patient using MRI alone and seven patients using either ratio. In four patients whose tumors could not be localized by MRI, the uncorrected and prolactin-adjusted ratios localized one tumor correctly and three tumors incorrectly. Only MRI correctly localized the one central microadenoma.

“We did not find any difference in localization rates by measurement of prolactin during IPSS,” she said. The small size of the study and its retrospective design invite further research in a more robust study.

Dr. Sharma reported having no financial disclosures.

From Clinical Endocrinology News