Homozygous TMEM127 mutations in 2 patients with bilateral pheochromocytomas.

Pheochromocytoma (PCC) and paraganglioma (PGL) are rare neuroendocrine tumors that are hereditary in up to 50% of patients. The gene encoding transmembrane-protein-127 (TMEM127) is one of the PCC/PGL-susceptibility genes with an autosomal dominant inheritance pattern. Here, we report 2 patients with bilateral PCC who both harbored a homozygous TMEM127-mutation. In a 31-year-old mentally retarded patient, the homozygous c.410-2A > G mutation was discovered during an update of DNA analysis. A 26-year-old mentally retarded patient was found to have a homozygous c.3G > A mutation. The parents of both patients were consanguineous. We reviewed previously reported clinical features of TMEM127 mutation carriers and compared our findings with case descriptions of homozygous mutations in other PGL/PCC-susceptibility genes. Homozygosity for an autosomal dominant inherited disorder is an extremely rare phenomenon and has, to our knowledge, not been reported before for the gene encoding TMEM127. In the present cases, the clinical picture does not seem to be very different from heterozygous TMEM127 mutation carriers, except for a relatively large tumor size and more pronounced plasma metanephrine concentration. It is unclear whether the mental retardation is causally related to homozygosity of the TMEM127 mutations. Updating genetic screening in patients in whom PCC/PGL has been diagnosed in the past should be considered as it might provide clinically relevant information.

The penetrance of paraganglioma and pheochromocytoma in SDHB germline mutation carriers.

Germline mutations in succinate dehydrogenase B (SDHB) predispose to hereditary paraganglioma (PGL) syndrome type 4. The risk of developing PGL or pheochromocytoma (PHEO) in SDHB mutation carriers is subject of recent debate. In the present nationwide cohort study of SDHB mutation carriers identified by the clinical genetics centers of the Netherlands, we have calculated the penetrance of SDHB associated tumors using a novel maximum likelihood estimator. This estimator addresses ascertainment bias and missing data on pedigree size and structure. A total of 195 SDHB mutation carriers were included, carrying 27 different SDHB mutations. The 2 most prevalent SDHB mutations were Dutch founder mutations: a deletion in exon 3 (31% of mutation carriers) and the c.423+1G>A mutation (24% of mutation carriers). One hundred and twelve carriers (57%) displayed no physical, radiological or biochemical evidence of PGL or PHEO. Fifty-four patients had a head and neck PGL (28%), 4 patients had a PHEO (2%), 26 patients an extra-adrenal PGL (13%). The overall penetrance of SDHB mutations is estimated to be 21% at age 50 and 42% at age 70 when adequately corrected for ascertainment. These estimates are lower than previously reported penetrance estimates of SDHB-linked cohorts. Similar disease risks are found for different SDHB germline mutations as well as for male and female SDHB mutation carriers.

The IGF2 methylation score for adrenocortical cancer: an ENSAT validation study.

Adrenocortical carcinoma (ACC) is diagnosed using the histopathological Weiss score (WS), but remains clinically elusive unless it has metastasized or grows locally invasive. Previously, we proposed the objective IGF2 methylation score as diagnostic tool for ACC. This multicenter European cohort study validates these findings. Patient and tumor characteristics were obtained from adrenocortical tumor patients. DNA was isolated from frozen specimens, where after DMR2, CTCF3, and H19 were pyrosequenced. The predictive value of the methylation score for malignancy, defined by the WS or metastasis development, was assessed using receiver operating characteristic curves and logistic and Cox regression analyses. Seventy-six ACC patients and 118 patients with adrenocortical adenomas were included from seven centers. The methylation score and tumor size were independently associated with the pathological ACC diagnosis (OR 3.756 95% CI 2.224-6.343; OR 1.467 95% CI 1.202-1.792, respectively; Hosmer-Lemeshow test P = 0.903), with an area under the curve (AUC) of 0.957 (95% CI 0.930-0.984). The methylation score alone resulted in an AUC of 0.910 (95% CI 0.866-0.952). Cox regression analysis revealed that the methylation score, WS and tumor size predicted development of metastases in univariate analysis. In multivariate analysis, only the WS predicted development of metastasis (OR 1.682 95% CI 1.285-2.202; P < 0.001). In conclusion, we validated the high diagnostic accuracy of the IGF2 methylation score for diagnosing ACC in a multicenter European cohort study. Considering the known limitations of the WS, the objective IGF2 methylation score could potentially provide extra guidance on decisions on postoperative strategies in adrenocortical tumor patients.

Congenital adrenal hyperplasia as a cause of adrenal incidentaloma.

Congenital adrenal hyperplasia (CAH) can present as a benign adrenal tumour, which should be treated medically. The diagnosis of CAH must be considered in a patient presenting with adrenal incidentaloma in order to avoid unnecessary adrenalectomy. Urinary steroid profiling is a useful diagnostic tool to identify the presence of CAH.

Preoperative pharmacological management of phaeochromocytoma.

Phaeochromocytoma is a rare catecholamine-secreting neuroendocrine tumour with a high cardiovascular morbidity and mortality if left untreated. Surgical resection is the only curative therapy. During surgery there is a high risk of massive release of catecholamines, which can result in potentially fatal hypertensive crises and cardiac arrhythmias. Administration of vasoactive drugs such as (non)selective alpha- and beta-antagonists and calcium channel blocking agents have reduced the operation risk. Guidelines for the preoperative medical management of the patient with a phaeochromocytoma are mainly based on retrospective studies and case reports. We reviewed the relevant literature on this subject. In addition, we compared the several preoperative treatment protocols of the eight university medical centres in the Netherlands.

Synchronous vs. Metachronous Metastases in Adrenocortical Carcinoma: an Analysis of the Dutch Adrenal Network.

Adrenal Cortical Carcinoma (ACC) is a rare malignancy with an incidence of 1.0 per million per year in the Netherlands. Median survival varies according to the European Network for the Study of Adrenal Tumours (ENS@T) tumour stage. It is unknown whether time until development of metastases is of influence on prognosis. To asses this, data were retrospectively obtained from centres of the Dutch Adrenal Network. Patients who presented with ACC between January 1, 2004 and October 31, 2013 were included. Date of detection of metastases, number of metastases and affected organs were registered. One hundred sixty patients were included in the analysis. Synchronous metastases were defined as diagnosis of metastasis ≤6 months after the initial diagnosis of ACC. Overall survival rate was calculated from the date of diagnosis of metastasis until death from any cause. At first presentation, 50 patients (31 %) had ACC with metastases (ENS@T stage IV). Another 67 (42 %) developed metastases during follow-up. Amongst the 117 patients with metastases, 84 (72 %) patients had synchronous metastases and 33 (28 %) developed metachronous metastases. Diagnosis of synchronous metastases (p = 0.046), more than one affected organ (p < 0.001) and four or more metastases (p < 0.001) were found to be associated with reduced overall survival. Limitations included retrospective design and limited details regarding pathological data. We conclude that synchronous metastases of ACC are associated with a poorer prognosis compared to metachronous metastases of ACC. The clinical characteristics associated with prognosis in this study support the view to refine the prognostic classification for patients with stage IV ACC.

[Tissue-specific changes in cortisol metabolism and their potential role in the metabolic syndrome]. / Weefselspecifieke veranderingen in het cortisolmetabolisme en hun mogelijke rol in het metabool syndroom.

The intracellular enzyme IIbeta-hydroxysteroid dehydrogenase (IIbetaHSD) catalyses the interconversion between the biologically-active cortisol and inactive cortisone. There are two distinct isozymes: IIbetaHSD type I behaves predominantly as a reductase in vivo and activates cortisone into cortisol, whereas IIbetaHSD type 2 functions as a dehydrogenase and inactivates cortisol into cortisone. At tissue level, IIbetaHSD type I amplifies the effect ofglucocorticoids, whereby free cortisol is generated from the relative excess of circulating free cortisone. Both animal and human studies have demonstrated that alterations in IIbetaHSD type I activity in adipose tissue and liver are associated with the metabolic syndrome, thus possibly reflecting a tissue-specific (omental) Cushing's syndrome. Pharmacological inhibition of IIbettaHSD type I activity provides an interesting mechanism for the development of novel therapeutic agents for type-2 diabetes mellitus.

Diagnostic Value of Urinary Steroid Profiling in the Evaluation of Adrenal Tumors.

Radiological examination may unexpectedly reveal an adrenal mass. Current algorithms for differentiating between benign and malignant lesions mainly rely on size and densitometry on unenhanced CT, which have limited specificity. We examined the diagnostic value of urinary steroid profiling by gas chromatography/mass-spectrometry (GC/MS) in differentiating between benign and malignant adrenal tumors. A retrospective study in two referral centers for patients with adrenal disease was performed. All urinary steroid profiles ordered for evaluation of an adrenal tumor between January 2000 and November 2011 were examined. Patients were diagnosed with adrenal cortical carcinoma (ACC), adrenal cortical adenoma (ACA), or other adrenal mass. Results of hormonal measurements, imaging studies, pathology reports, and clinical outcome were retrieved from medical records. The diagnostic value of individual urinary steroid metabolites was determined by receiver operating characteristics analysis. Cut-off values were compared to reference values from an age and gender-standardized population of healthy controls. Eighteen steroid metabolites were excreted in significantly higher concentrations in patients with ACC (n = 27) compared to patients with ACA (n = 107) or other adrenal conditions (n = 18). Tetrahydro-11-deoxycortisol (THS) at a cut-off value of 2.35 µmol/24 h differentiated ACC from other adrenal disorders with 100% sensitivity and 99% specificity. Elevated urinary excretion of THS was associated with a very high sensitivity and specificity to differentiate between an ACC and a benign adrenal mass. Urinary steroid profiling might be a useful diagnostic test for the evaluation of patients with an adrenal incidentaloma.

Clinical and biochemical changes following 131I therapy for hyperthyroidism in patients not pretreated with antithyroid drugs.

BACKGROUND: Radioiodine therapy (131I) for the treatment of hyperthyroidism has been shown to be effective and safe. Despite the extensive experience with radioiodine therapy, the necessity for pretreatment with antithyroid drugs is controversial. Pretreatment is partly based on the concept that antithyroid drugs deplete the thyroidal hormonal stores, thereby reducing the risk of a radioiodine-induced aggravation of hyperthyroidism or thyroid storm. Few data are available on the frequency of clinically significant exacerbations of hyperthyroidism following 131I therapy without prior treatment with antithyroid drugs. The aim of the present study was to determine prospectively the early clinical and biochemical changes after 131I therapy in patients who were not pretreated with antithyroid drugs. METHODS: Patients with Graves' disease (n = 21), toxic multinodular goiter (n = 11) or toxic adenoma (n = 2) were studied before and after 131I therapy. Clinical and biochemical parameters of thyroid function were investigated before and 1, 2, 8, 11, 18 and 25 days after 131I treatment. Patients were given no antithyroid drugs prior to 131I therapy, all patients received beta-blocking agents for symptomatic relief. RESULTS: In 19 of 34 patients, a transient increase in thyroid hormone levels was observed, predominantly in the first week following 131I therapy. None of these patients experienced worsening of thyrotoxic symptoms. This transient increase in thyroid hormone levels was demonstrated in all patients with toxic multinodular goiter, whereas it was found in only six of 21 patients with Graves' disease. This difference could not readily be explained by differences in pretreatment thyroid hormone levels, administered dose or effectively absorbed dose of 131I. CONCLUSIONS: 131I treatment of hyperthyroidism without pretreatment with antithyroid drugs may cause a transient increase in thyroid hormone levels. Clinically significant exacerbations of hyperthyroidism were, however, not observed in our study population. Increased hormone levels following 131I therapy were more often seen in patients with toxic multinodular goiter than in patients with Graves' disease.

[11 beta-hydroxysteroid-dehydrogenase: characteristics and the clinical significance of a key enzyme in cortisol metabolism]. / 11 beta-hydroxysteroïddehydrogenase: eigenschappen en klinische betekenis van een sleutelenzym in het cortisolmetabolisme.

The enzyme 11 beta HSD catalyzes the interconversion of the biologically active cortisol and the biologically inactive cortisone. There are two distinct isozymes: 11 beta HSD type 1 is mainly expressed in liver and is a bidirectional enzyme, with both dehydrogenase and reductase activity. 11 beta HSD type 2 is mainly expressed in kidney and is a unidirectional enzyme with only dehydrogenase activity. 11 beta HSD type 2 protects the mineralocorticoid receptor from being activated by cortisol. Thus, specificity of this receptor in vivo is enzyme and not receptor mediated. The syndrome of apparent mineralocorticoid excess is caused by a congenital deficiency of 11 beta HSD type 2. Liquorice-induced hypertension is an example of an acquired defect in dehydrogenase activity of 11 beta HSD, caused by glycyrrhetinic acid. 11 beta HSD may play a role in the pathogenesis of 'essential' hypertension, obesity and type 1 diabetes mellitus. Angiotensin-converting enzyme inhibitors enhance dehydrogenase activity of 11 beta HSD, which may contribute to their natriuretic effect.

[Diagnostic image (50) Positive Pemberton's sign]. / Diagnose in beeld (50). Positief teken van Pemberton.

A 32-year-old woman had a progressive euthyroid goitre and dyspnoea. Pemberton's sign was found to be positive: elevation of both arms resulted in an inspiratory stridor and venous congestion. Symptoms and signs resolved after total thyroidectomy.

[Elevated hormone levels without endocrinopathy: hypercortisoluria and hypoglycemia as facticious disorders]. / Hormonale overmaat zonder endocrinopathie: hypercortisolurie en hypoglykemie als nagebootste stoornissen.

A 29-year-old female patient with weight gain and intermittent hypertension was suspected of having Cushing's syndrome due to conspicuous hypercortisoluria. Specific laboratory tests demonstrated that the urine samples contained prednisolone, which had resulted in a false positive elevation of urine-free cortisol measurements. The patient admitted to having taken prednisolone tablets and also to having added them to several urine collections. In a 21-year-old male patient with unexplained hypoglycaemia, hypoglycaemia was recorded during a 72-hour fast together with an elevated level of plasma insulin and a low level of plasma C-peptide. The presence of insulin autoantibodies could be excluded, making a diagnosis of factitious hypoglycaemia highly likely. Both patients were confronted with the factitious disorder and received psychiatric counselling, after which no further problems arose. Where excessive hormone levels occur, the possibility of a factitious disorder needs to be considered. In such cases, specific supplementary laboratory tests may prove helpful.

Intestinal pseudo-obstruction as a complication of paragangliomas: case report and literature review.

Intestinal pseudo-obstruction is a rare and relatively unknown complication of phaeochromocytoma÷ paraganglioma (PCC÷PGL). Its pathophysiology can be explained by the hypersecretion of catecholamines, which may reduce the peristaltic activity of the gastrointestinal tract. Clinically, this can result in chronic constipation, intestinal pseudo-obstruction or even intestinal perforation. We conducted a comprehensive literature search and retrieved 34 cases of pseudo-obstruction caused by either benign or malignant PCC÷PGL. We also included a case from our centre that has not been described earlier. We conclude that intestinal pseudo-obstruction is a rare but potentially life-threatening complication of PCC÷PGL. Intravenous administration of phentolamine is the most frequently described treatment when surgical resection of the PCC÷PGL is not feasible.

A liquid chromatography tandem mass spectrometry assay for plasma renin activity using online solid-phase extraction.

BACKGROUND: The plasma renin activity (PRA) assay measures the ability of renin to generate angiotensin I (AngI) from angiotensinogen. It is used to monitor mineralocorticoid therapy and to screen hypertensive individuals for primary aldosteronism (PA). METHODS: Samples were incubated in the presence of protease inhibitors for 6.5 and 24 h. The reaction was stopped by the addition of 2% ammonium hydroxide. AngI was then quantified by liquid chromatography tandem mass spectrometry using online solid-phase extraction (XLC-MS/MS). RESULTS: This method requires a sample volume of 50 µL and has an inter-assay precision <14% across the working range. A 6.5-h incubation gave a lower limit of quantification (LLOQ) of 0.3 nmol/L/h and this can be reduced to 0.08 nmol/L/h using a 24-h incubation. Comparison to a radioimmunoassay revealed excellent correlation (r(2) = 0.98), but a 37% negative bias. We also found that renin is stable in whole blood for up to 24 h at room temperature. In contrast, storage at 4°C should be avoided as prorenin cryoactivation can affect the PRA result in some patient groups. CONCLUSIONS: We have developed and fully validated a semi-automated XLC-MS/MS method for the measurement of PRA. In addition, a reference range specific to this assay has been defined. We have also demonstrated that renin is stable for up to 24 h at room temperature. This will enable this assay to be extended to samples taken in primary care, potentially increasing the number of hypertensive patients who can be screened for PA.

A rare cause of congenital adrenal hyperplasia: Antley-Bixler syndrome due to POR deficiency.

Cytochrome P450 oxidoreductase (POR) deficiency is a recently discovered new variant of congenital adrenal hyperplasia. Distinctive features of POR deficiency are the presence of disorders of sexual development in both sexes, glucocorticoid deficiency and skeletal malformations similar to those observed in the Antley-Bixler syndrome.

Incidence of venous thromboembolism in patients with Cushing's syndrome: a multicenter cohort study.

CONTEXT: Venous thrombosis has frequently been reported in patients with endogenous Cushing's syndrome (CS). OBJECTIVE: The aim of this study was to evaluate the incidence of venous thromboembolism (VTE) in patients with CS prior to treatment and after surgery. DESIGN AND SETTING: We conducted a multicenter cohort study at all university medical centers in The Netherlands. PATIENTS: Consecutive patients diagnosed with endogenous CS of benign origin between January 1990 and June 2010 were eligible for inclusion. Patients surgically treated for nonfunctioning pituitary adenoma served as controls for the incidence of postoperative VTE in ACTH-dependent CS. MAIN OUTCOME MEASURES: We documented all objectively confirmed VTE during 3 yr prior to, and 3 yr after treatment onset. The incidences of VTE were expressed as incidence rates. RESULTS: A total of 473 patients (mean age 42 yr, 363 women) were included (360 ACTH-dependent pituitary CS). The total number of person-years was 2526. Thirty-seven patients experienced VTE during the study period, resulting in an incidence rate of 14.6 [95% confidence interval (CI) 10.3-20.1] per 1000 person-years. The incidence rate for first-ever VTE prior to treatment was 12.9 (95% CI 7.5-12.6) per 1000 person-years (17 events). The risk of postoperative VTE, defined as risk within 3 months after surgery, was 0% for ACTH-independent and 3.4% (95% CI 2.0-5.9) for ACTH-dependent CS (12 events in 350 patients); most events occurred between 1 wk and 2 months after surgery. Compared with the controls, the risk of postoperative VTE in patients undergoing transsphenoidal surgery was significantly greater (P = 0.01). CONCLUSIONS: Patients with CS are at high risk of VTE, especially during active disease and after pituitary surgery. Guidelines on thromboprophylaxis are urgently needed.