Cyclic Cushing’s syndrome: a clinical challenge

Posted on August 11, 2013 by MaryO
  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

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What is the Best Approach to Suspected Cyclical Cushing Syndrome?

Posted on August 2, 2013 by MaryO

Strategies for Managing Cushing’s Syndrome With Variable Laboratory Data

Brew Atkinson, Karen R. Mullan

Disclosures

Clin Endocrinol. 2011;75(1):27-30.

 

Abstract

Cyclical Cushing’s syndrome is a pattern of hypercortisolism in which the biochemistry of cortisol production fluctuates rhythmically. This syndrome is often associated with fluctuating symptoms and signs. It is now being increasingly recognized. The phenomenon is important because it can, if not recognized, lead to errors in diagnosis and differential diagnosis of the syndrome and in assessment of therapeutic outcomes. The techniques and criteria, protocols and dynamic biochemical tools to detect cycling in patients with hypercortisolism are discussed as are the strategies for diagnosing and managing this important subgroup of patients with hypercortisolism.

Introduction

Cyclical Cushing’s syndrome (CS) is a pattern in hypercortisolism in which the biochemistry of cortisol production fluctuates rhythmically. This can also be associated with fluctuating symptoms and signs. This type of case was initially thought to be rare. However, it has recently been recognized as occurring much more frequently. The phenomenon is important because, if not recognized, it can lead to errors in diagnosis and differential diagnosis of the syndrome and in assessment of therapeutic outcomes. All of these can have very serious clinical consequences.

As a result of reading this article, it is hoped that readers will be better able to consider more carefully the risks associated with too wide a diagnostic trawl for the diagnosis of CS and the associated chances of finding some abnormality of steroid biochemistry.

In cases where the diagnosis is being strongly considered, the risks of not considering episodic secretion when laboratory results are discordant are discussed. Readers should be able to plan strategies to assess for variable and cyclical secretion and to use these in diagnosis, differential diagnosis and treatment assessments.

Read more here: What is the best approach to suspected cyclical Cushing syndrome?

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