The Role of Adrenal Scintigraphy in the Diagnosis of Subclinical Cushing’s Syndrome and the Prediction of Post-surgical Hypoadrenalism

World J Surg. 2014 Mar 11. [Epub ahead of print]

Abstract

BACKGROUND:

Management of subclinical Cushing’s syndrome (SCS) remains controversial; it is not possible to predict which patients would benefit from adrenalectomy. In the present study we aimed to evaluate the role of adrenocortical scintigraphy (ACS) in the management of patients with SCS.

METHODS:

The medical records of 33 consecutive patients with adrenal “incidentaloma” and proven or suspected SCS who underwent 131I-19-iodocholesterol ACS between 2004 and 2010 were reviewed. Sixteen underwent laparoscopic adrenalectomy (surgical group-S-group) and 17 were medically managed (medical group-M-group). Follow-up evaluation was obtained by outpatient consultation.

RESULTS:

Overall 25 patients (15 in the S-group and 10 in the M-group) had concordant unilateral uptake at ACS (ACS+). In the S-group, the mean follow-up duration was 30.9 ± 16.1 months and, irrespective of the presence of hormonal diagnosis of SCS, in patients who were ACS+ adrenalectomy resulted in a significant increase in HDL cholesterol and decreases in body mass index, glycemia, and blood pressure (BP). One patient reduced antihypertensive medication and three others were able to discontinue it altogether. Prolonged postoperative hypoadrenalism (PH) occurred in 14 patients in the S-group. The overall accuracy in predicting PH was 93.7 % for ACS and 68.7 % for laboratory findings. In the M-group, the mean follow-up duration was 31.5 ± 26.3 months and no patient developed overt Cushing’s syndrome, although ACS+ patients experienced a worsening in glycemia and diastolic BP.

CONCLUSIONS:

Adrenal scintigraphy seems the most accurate diagnostic test for SCS. It is able to predict the metabolic outcome and the occurrence of PH, identifying the patients who could benefit from adrenalectomy irrespective of hormonal diagnosis.

PMID:
24615601
[PubMed – as supplied by publisher]

From http://www.ncbi.nlm.nih.gov/pubmed/24615601

Salivary cortisol performs better than urinary free cortisol to diagnose Cushing’s syndrome

Late-night salivary cortisol has a better performance than urinary free cortisol in the diagnosis of Cushing’s syndrome.

Salimetrics highlights a recent study:  Abstract

Context: The comparison of variability, reproducibility, and diagnostic performance of late-night salivary cortisol (LNSF) and urinary free cortisol (UFC) using concurrent and consecutive samples in Cushing’s syndrome (CS) is lacking.

Objectives, Patients and Methods: In a prospective study, we evaluate three simultaneous and consecutive samples of LNSF by RIA and UFC by LC-MS/MS in Cushing’s disease (CD; n=43), adrenal CS patients (n=9) and obese subjects (n=18) in order to compare their diagnostic performances. In CS patients we also performed a modified Cushing’s syndrome severity index (CSI).

Results: There was no difference in the coefficient of variation (%) between LNSF and UFC among the three samples obtained for each patient with CD (35±26vs31±24), adrenal CS (28±14vs22±14) and obesity (39±37vs48±20). LNSF confirmed the diagnosis of hypercortisolism even in the presence of normal UFC in 17.3% of CS, whereas the inverse situation was not observed for UFC. The area under the ROC curves for LNSF was 0.999 (95%CI 0.990-1.00) and for UFC was 0.928 (95%CI 0.809- 0.987). The ratio between AUCs was 0.928 (95%CI 0.810-0.988) indicating better performance of LNSF than UFC in diagnosing CS. There was no association between the severity of CSI and the degree of biochemical hypercortisolism.

Conclusion: Our data show that despite similar variability between both methods, LNSF has a superior diagnostic performance than UFC and should be used as the primary biochemical diagnostic test for Cushing’s syndrome diagnosis.

Authors Elias P, Martinez E, Barone B, Mermejo L, Castro M, Moreira A
Division of Endocrinology-Department of Medicine and Division of Statistics- Department of Social Medicine, Ribeirao Preto Medical School – University of Sao Paulo, Ribeirao Preto, SP- Brazil
LINK to Paper
Salimetrics guide to Cortisol
LINK to Salimetrics Diagnostic Salivary Cortisol Assay

Mutations in PKA catalytic subunit associated with Cushing’s syndrome

1. Somatic mutations resulting in constitutive activation of PRKACA, which encodes the catalytic subunit of protein kinase A, were found in 37% of patients with Cushing’s syndrome due to an adrenal adenoma. 

2. Germline duplications of PRKACA were detected in patients with bilateral adrenal hyperplasia and overt Cushing’s syndrome. 

Study Rundown: This study found that 37% of patients with overt Cushing’s syndrome due to an adrenal adenoma have a somatic mutation in PRKACA, which encodes the catalytic subunit of cyclic AMP-dependent protein kinase A (PKA), present in their tumor cells. The most commonly identified variant, Leu206Arg, results in impaired interaction between the catalytic and regulatory subunits of PKA, thereby causing constitutive activation of PKA. Additionally, a subset of patients with cortisol-producing bilateral adrenal hyperplasia harbored germline duplications of PRKACA.

This is the first study to identify an association between genetic alterations of the catalytic subunit of PKA and Cushing’s syndrome. It is significant that 37% of patients with overt Cushing’s syndrome were found to have tumors with PRKACA mutations; previous research had revealed only very rare mutations. Of note, this study did not find PRKACA mutations in any patients with subclinical Cushing’s syndrome or inactive adenomas. This suggests that Cushing’s syndrome and subclinical Cushing’s are distinct entities. Patients involved in this study were recruited from only three centers; the frequency of PRKACA mutations in Cushing’s syndrome may be different in other study populations. Further research will be needed to identify biochemical causes of overt Cushing’s syndrome in patients without PRKACA mutations.

Relevant Reading: Abnormalities of cAMP signaling are present in adrenocortical lesions associated with ACTH-independent Cushing’s syndrome despite the absence of mutations in known genes

In-Depth: In this study, exome sequencing of tumor specimens from 10 patients with unilateral cortisol-producing adenomas and overt Cushing’s syndrome was performed. Eight of 10 adenomas had somatic mutations in PRKACA; 7 of these patients had the same mutation (p.Leu206Arg). Subsequently, PRKACA was sequenced in 129 additional patients with adrenal adenomas. Patients were classified as having overt Cushing’s syndrome (at least three abnormal biochemical tests or catabolic features plus two abnormal tests), subclinical Cushing’s (at least one abnormal biochemical test without catabolic signs) or as having an inactive adenoma. The Leu206Arg variant was identified in tumor tissue of 14/129 patients and all 14 had overt Cushing’s syndrome. Overall, 37% (22/59) of patients with overt Cushing’s syndrome due to an adenoma had a PRKACA mutation; in contrast, PRKACA mutations were not found in any patients with subclinical Cushing’s or an inactive adenoma. Of 35 patients with overt Cushing’s syndrome due to cortisol-secreting bilateral adrenal hyperplasia, 5 patients had copy-number gains of a region on chromosome 19p that contains PRKACA.

Analysis of holoenzyme structure revealed that the Leu206Arg mutation is located in the active-site cleft of the catalytic subunit of PKA. To evaluate the functional consequences of this mutation, cells were transfected with either nonmutant or variant C-alpha, which encodes the catalytic subunit of PKA. Investigators determined that the mutation causes constitutive activation of the catalytic subunit by impairing interaction with the regulatory subunit of PKA.

From http://www.2minutemedicine.com/mutations-in-pka-catalytic-subunit-associated-with-cushings-syndrome/

Suspected case of Cushing’s Syndrome with history of taking medicines prescribed by registered Chinese medicine practitioner

The Department of Health (DH) today (February 18) alerted clients who have consulted a registered Chinese medicine practitioner (CMP) Mr Chan Kong-kin (CMP Chan), practising at G/F, No.25, Leung Tin Village in Tuen Mun, should consult health-care professionals for advice if they have been supplied with medicines suspected to be Western medicines.

The appeal followed the DH’s investigation into two public complaints. The first complaint involved a 23-year-old woman who consulted CMP Chan for management of eczema. She was given a type of green pills, two types of yellow pills and a type of red-yellow capsules for treatment of her disease for about one year.

She developed round face and increased facial hair which are features compatible with Cushing’s syndrome and steroid overdose can cause the syndrome. The patient was admitted to a public hospital on February 5 for investigation and was discharged on February 7.

The second complaint involved a 24-year-old woman who was recommended by the first complainant to consult CMP Chan for management of allergic rhinitis and eczema. She was given similar medicines as those for the first complainant for three days.

Her condition was stable.

Today, chemical analysis by the Government Laboratory on the patients’ drug samples showed that Western medicine Dexamethasone was detected in the red-yellow capsule.

Dexamethasone is a potent steroid. Taking dexamethasone for a long time, especially when in substantial dosage, can cause side effects such as moon face, high blood pressure, high blood sugar, muscle atrophy, peptic ulcer and even osteoporosis.

DH has set up a hotline 2125 1133 for public enquiries related to the medicines prescribed by the CMP.

It will operate from 9am to 9pm, Monday to Friday.

“Preliminary investigation by the DH revealed that pills and capsules were found in the CMP’s premises and all have been seized for further investigation,” the spokesman said.

“In December 31, 2012, the DH announced that CMP Chan was found in possession of Part I poisons and unregistered pharmaceutical products in the same clinic which also involved medicines with steroid. The DH subsequently took enforcement action and the relevant legal proceeding is in progress.

The case has also been referred to the Chinese Medicine Council of Hong Kong for follow-up action,” the spokesman added

“On completion of our investigation, the DH will seek advice from the Department of Justice regarding possible contravention of the Pharmacy and Poisons Ordinance (Cap 138) for the illegal sale or possession of Part I poisons. According to the Ordinance, the maximum penalty for each offence is a fine of $100,000 and two years’ imprisonment. Besides, the DH will also refer this case to the Chinese Medicine Council of Hong Kong for possible disciplinary action”, the spokesman remarked.

People who have been supplied with medicines by the concerned CMP and are in doubt should consult health-care professionals as soon as possible.

They should submit the medicines to the Chinese Medicine Division of DH at 16/F, AIA Kowloon Tower, Landmark East, 100 How Ming Street, Kwun Tong, during office hours for disposal.

Source: HKSAR Government

From http://7thspace.com/headlines/453015/suspected_case_of_cushings_syndrome_with_history_of_taking_medicines_prescribed_by_registered_chinese_medicine_practitioner.html

Polycystic ovarian syndrome and Cushing’s syndrome: A persistent diagnostic quandary

European Journal of Obstetrics & Gynecology and Reproductive Biology, 02/10/2014  Clinical Article

Brzana J, et al. – This study aims to retrospectively review institutional records of female patients of reproductive age with Cushing’s disease (CD) and determine if and how many had been previously diagnosed as having solely PCOS. To determine whether clinical patterns might be useful in identifying appropriate candidates for hypercortisolism screening in women suspected of PCOS. Prolonged exposure to hypercortisolism has been linked with increased mortality and morbidity. Tests for hypercortisolism in all the PCOS cases authors report led to an appropriate CD diagnosis. Future research should focus on when and which (if not all) women with suspected PCOS should be tested for hypercortisolism.

Methods

  • The study included 50 patients with pathologically proven CD at Oregon Health & Science University, Northwest Pituitary Center between 2006 and 2011.
  • Physical, clinical, and biochemical features for hypercortisolism were compared.

Results

  • Of 50 patients with pathologically proven CD, 26 were women of reproductive age.
  • Of these, half had previously been diagnosed with and treated initially solely for PCOS.
  • Hirsutism and menstrual abnormalities were more common in the group with an initial PCOS diagnosis than in the group with an initial CD diagnosis.

From http://www.mdlinx.com/endocrinology/newsl-article.cfm/5055779/ZZ4747461521296427210947/?news_id=2364&newsdt=021014&subspec_id=1509&utm_source=Focus-On&utm_medium=newsletter&utm_content=Top-New-Article&utm_campaign=article-section