Clinical Characteristics and Postoperative Outcomes of Primary Aldosteronism in the Elderly

CONTEXT

Primary aldosteronism (PA) in the elderly has increased in importance in association with population aging.

OBJECTIVE

To investigate the characteristics and outcomes of elderly patients with PA undergoing adrenalectomy.

PATIENTS AND METHODS

Using a database of patients with PA who underwent adrenal venous sampling (AVS), we compared elderly patients (≥65 years old) with nonelderly patients (<65 years old) in terms of characteristics, subtype classification in ACTH-stimulated AVS, and outcomes after adrenalectomy.

RESULTS

The elderly group had a higher prevalence of comorbidities than the nonelderly group. The proportion of the unilateral subtype [defined as a lateralization index (LI) >4] was comparable between the age groups. In patients who received adrenalectomy, biochemical cure was comparable between the groups, whereas persistent hypertension was more common in the elderly group. The prevalences of hyperkalemia and renal impairment (chronic kidney disease stage 3b or higher) were higher in the elderly group. Multiple regression analysis showed that the duration of hypertension predicted persistent hypertension and hyperkalemia and that preoperative estimated glomerular filtration rate predicted renal impairment in the elderly group. LI >4 in AVS was an independent predictor of biochemical cure after adrenalectomy in the elderly group but not in the nonelderly group. Age was negatively associated with biochemical cure in patients with LI ≤4.

CONCLUSION

Adrenalectomy contributes to biochemical improvement in elderly patients if determined in accordance with AVS. The treatment strategy should be determined considering the high postoperative incidence of persistent hypertension and hyperkalemia in elderly patients with a long history of hypertension or renal impairment in those with reduced renal function.

Epidermal growth factor receptor/extracellular signal-regulated kinase pathway enhances mineralocorticoid receptor transcriptional activity through protein stabilization

Activation of mineralocorticoid receptor (MR) is evoked by aldosterone, and it induces hypertension and cardiovascular disease when it's concomitant with excessive salt loading. We have proposed the notion of "MR-associated hypertension", in which add-on therapy of MR blockers is effective even though serum aldosterone level is within normal range. To elucidate its underlying molecular mechanism, we focused on the effect of epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinase (ERK) activation on MR activity. Epidermal growth factor (EGF) administration increased MR transcriptional activity through EGFR/ERK pathway and increased protein level by counteracting MR ubiquitylation in vitro. EGF administration in vivo also increased MR protein level and target gene expression in kidney, which were decreased by EGFR inhibitor. In addition, the administration of EGFR inhibitor lowered systolic blood pressure and MR activity in DOCA/salt-treated mice. In conclusion, EGFR/ERK pathway activation is considered as one of the underlying mechanisms of aberrant MR activation and EGFR/ERK pathway blockade could be an alternative approach for the prevention of MR-related cardiovascular events.

Pulmonary nocardiosis mimicking small cell lung cancer in ectopic ACTH syndrome associated with transformation of olfactory neuroblastoma: a case report

Background

Pulmonary nocardiosis frequently develops as an opportunistic infection in cell-mediated immunosuppressive patients, and sometimes requires differentiation from pulmonary malignancy. Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a neoplastic disorder which leads to impaired cell-mediated immunity, and is commonly associated with small cell lung cancer (SCLC). Because pulmonary infection and causative malignancy can appear as pulmonary lesions with EAS, differentiation of these diseases remains a critical issue for physicians.

Case presentation

A 52-year-old woman with progressive lower limb paralysis and general fatigue was referred to us. She had been diagnosed with olfactory neuroblastoma (ONB) and treated with surgery and radiation therapy 10 years before the referral and had required stereotactic radiosurgery and chemotherapy 4 years later for a relapse of the ONB. On referral, she presented with Cushing’s syndrome with elevated cortisol and ACTH levels. Potassium supplement improved her symptoms; however, a month later, she was urgently hospitalized due to acute pleuritic chest pain on inspiration. Chest computed tomography revealed left lower lobular consolidations and a contralateral nodule in the right middle lobe. The clinical history and laboratory work-up suggested that her Cushing’s syndrome had most likely arisen from EAS. Additionally, the lungs were suspected as the ACTH source due to high levels of progastrin-releasing peptide and progressive pulmonary consolidation with a contralateral nodule, suggesting SCLC. However, histological examination from bronchoscopy revealed no evidence of malignancy, and Nocardia cyriacigeorgica was isolated from bronchoalveolar lavage fluid. Sulfamethoxazole/trimethoprim improved her pulmonary lesions. Somatostatin receptor scintigraphy revealed strong tracer uptake in the ONB lesions, indicating that the origin of the EAS was the olfactory tumor. However, histological examination of ONB specimens resected 10 years earlier showed no intracytoplasmic immunopositivity for ACTH.

Conclusions

We highlight a rare case of pulmonary nocardiosis, which was associated with EAS mimicking SCLC, and was related to ONB transformation. Nocardiosis has to be considered even though anamnestic, clinical, and radiological aspects suggest the presence of metastasis. Additionally, physicians should carefully monitor patients with ONB for the development of Cushing’s symptoms because the tumor can transform into an ACTH-producing form, even after long-term follow-up.

Intestinal Mineralocorticoid Receptor Contributes to Epithelial Sodium Channel-Mediated Intestinal Sodium Absorption and Blood Pressure Regulation

Background

Mineralocorticoid receptor (MR) has pathological roles in various cell types, including renal tubule cells, myocytes, and smooth muscle cells; however, the role of MR in intestinal epithelial cells (IECs) has not been sufficiently evaluated. The intestine is the sensing organ of ingested sodium; accordingly, intestinal MR is expected to have essential roles in blood pressure (BP) regulation.

Methods and Results

We generated IEC‐specific MR knockout (IEC‐MR‐KO) mice. With a standard diet, fecal sodium excretion was 1.5‐fold higher in IEC‐MR‐KO mice, with markedly decreased colonic expression of β‐ and γ‐epithelial sodium channel, than in control mice. Urinary sodium excretion in IEC‐MR‐KO mice decreased by 30%, maintaining sodium balance; however, a low‐salt diet caused significant reductions in body weight and BP in IEC‐MR‐KO mice, and plasma aldosterone exhibited a compensatory increase. With a high‐salt diet, intestinal sodium absorption markedly increased to similar levels in both genotypes, without an elevation in BP. Deoxycorticosterone/salt treatment elevated BP and increased intestinal sodium absorption in both genotypes. Notably, the increase in BP was significantly smaller in IEC‐MR‐KO mice than in control mice. The addition of the MR antagonist spironolactone to deoxycorticosterone/salt treatment eliminated the differences in BP and intestinal sodium absorption between genotypes.

Conclusions

Intestinal MR regulates intestinal sodium absorption in the colon and contributes to BP regulation. These regulatory effects are associated with variation in epithelial sodium channel expression. These findings suggest that intestinal MR is a new target for studying the molecular mechanism of hypertension and cardiovascular diseases.

Correlation Between Lateralization Index of Adrenal Venous Sampling and Standardized Outcome in Primary Aldosteronism

Objectives

The aim of this study was to investigate the impact of adrenal venous sampling (AVS) lateralization cutoffs on surgical outcomes.

Patients and Methods

Cosyntropin-stimulated AVS was used to guide surgical management of 377 patients with primary aldosteronism (PA) who were evaluated 6 months after surgery.

Main Outcome Measures

The proportion of patients that achieved clinical benefit and complete biochemical success based on the AVS aldosterone lateralization index (LI) was determined.

Results

Clinical benefit was achieved in 29 of 47 patients with an LI between 2 and 4, in 66 of 101 with an LI between 4 and 10, and in 158 of 203 with an LI > 10 (P < 0.01 for trend). Complete biochemical success was achieved in 27 of 42 with an LI between 2 and 4, in 60 of 76 with an LI between 4 and 10, and in 127 of 155 with an LI > 10 (P = 0.024 for trend). After adjustment for confounders and using those patients with an LI between 2 and 4 as a reference, a clinical benefit was associated only with those with an LI > 10 (OR, 2.30; 95% CI, 1.03 to 5.16), whereas complete biochemical success was associated with those with an LI between 4 and 10 (OR, 2.83; 95% CI, 1.14 to 7.01) or LI > 10 (OR, 3.55; 95% CI, 1.47 to 8.55).

Conclusions

Difference of clinical outcome was relatively small when strict LI diagnostic threshold was used; biochemical cure was sufficiently achieved when an LI > 4 was used. Our study by standardized outcome measures validated that an LI > 4 may be appropriate for determining unilateral disease in PA.

Accuracy of adrenal computed tomography in predicting the unilateral subtype in young patients with hypokalaemia and elevation of aldosterone in primary aldosteronism

CONTEXT

The current Endocrine Society Guideline suggests that patients aged <35 years with marked primary aldosteronism (PA) and unilateral adrenal lesions on adrenal computed tomography (CT) scan may not need adrenal vein sampling (AVS) before proceeding to unilateral adrenalectomy. This suggestion is, however, based on the data from only one report in the literature.

OBJECTIVE

We sought to determine the accuracy of CT findings in young PA patients who had unilateral adrenal disease on CT with hypokalaemia and elevation of aldosterone.

DESIGN AND PATIENTS

We retrospectively studied 358 PA patients (n = 30, aged <35 years; n = 39, aged 35-40 years; n = 289, aged ≥40 years) with hypokalaemia and elevation of aldosterone and unilateral disease on CT who had successful AVS.

MAIN OUTCOME MEASURE

Accuracy of CT findings is determined by AVS findings and/or surgical outcomes in patients aged <35 years.

RESULTS

Concordance of the diagnosis between CT and AVS was 90% (27/30) in patients aged <35 years, 79% (31/39) in patients aged 35-40 years and 69% (198/289) in those aged ≥40 years (trend for P < .01). Surgical benefit was confirmed in three patients aged <35 years and in three patients aged 35-40 years with the available surgical data who had discordance between CT and AVS findings. Collectively, the diagnostic accuracy of CT findings was 100% (30/30) if aged <35 years and 87% (34/39) if aged 35-40 years.

CONCLUSION

Primary aldosteronism patients aged <35 years with hypokalaemia and elevation of aldosterone and unilateral disease on adrenal CT could be spared AVS.

The Occurrence of Apparent Bilateral Aldosterone Suppression in Adrenal Vein Sampling for Primary Aldosteronism

Context

In adrenal venous sampling (AVS) for patients with primary aldosteronism (PA), apparent bilateral aldosterone suppression (ABAS), defined as lower aldosterone/cortisol ratios in the bilateral adrenal veins than that in the inferior vena cava, is occasionally experienced. ABAS is uninterpretable with respect to lateralization of excess aldosterone production. We previously reported that ABAS was not a rare phenomenon and was significantly reduced after adrenocorticotropic hormone (ACTH) administration.

Objective

To validate the effects of ACTH administration and adding sampling positions in the left adrenal vein on the prevalence of ABAS in the larger Japan Primary Aldosteronism Study.

Patients

The data from 1689 patients with PA who underwent AVS between January 2006 and October 2016 were studied. All patients in the previous study, the West Japan Adrenal Vein Sampling study, were excluded.

Outcome Measurements

The prevalence of ABAS was investigated at two sampling positions in the left adrenal vein, the central vein and the common trunk, without and with ACTH administration.

Results

The prevalence of ABAS with ACTH administration was significantly lower than that without ACTH administration [without ACTH vs with ACTH: 79/440 (18.0%) vs 45/591 (7.6%); P < 0.001]. With ACTH administration, the prevalence of ABAS was not different between the sampling position, at the central vein and at the common trunk [33/591 (5.6%) vs 32/591 (5.4%); P = 1.00].

Conclusions

The effectiveness of ACTH administration for the reduction of ABAS in AVS regardless of the sampling position in the left adrenal vein was confirmed in the larger cohort.

Significance of Computed Tomography and Serum Potassium in Predicting Subtype Diagnosis of Primary Aldosteronism

CONTEXT

The number of centers with established adrenal venous sampling (AVS) programs for the subtype diagnosis of primary aldosteronism (PA) is limited.

OBJECTIVE

Aim was to develop an algorithm for AVS based on subtype prediction by computed tomography (CT) and serum potassium.

DESIGN

A multi-institutional retrospective cohort study in Japan.

PATIENTS

A total of 1591 patients with PA were classified into four groups according to CT findings and potassium status. Subtype diagnosis of PA was determined by AVS.

MAIN OUTCOME MEASURE

Prediction value of the combination of CT findings and potassium status for subtype diagnosis.

RESULTS

The percentages of unilateral hyperaldosteronism on AVS were higher in patients with unilateral disease on CT than those with bilateral normal results on CT (50.8% vs 14.6%, P < 0.01), and these percentages were higher in those with hypokalemia than those with normokalemia (58.4% vs 11.5%, P < 0.01). The prevalence and odds ratio for unilateral hyperaldosteronism on AVS were as follows: bilateral normal on CT with normokalemia, 6.2% (reference); unilateral disease on CT with normokalemia, 23.8% and 4.8 [95% confidence interval (CI), 3.1 to 7.2]; bilateral normal on CT with hypokalemia, 38.1% and 9.4 (95% CI, 6.2 to 14.1), and unilateral disease on CT with hypokalemia, 70.6% and 36.4 (95% CI, 24.7 to 53.5).

CONCLUSIONS

Patients with PA with bilateral normal results on CT and normokalemia likely have a low prior probability of a lateralized form of AVS and could be treated medically, whereas those with unilateral disease on CT and hypokalemia have a high probability of a lateralized form of AVS.

Two-stage resection of a bilateral pheochromocytoma and pancreatic neuroendocrine tumor in a patient with von Hippel-Lindau disease: A case report

INTRODUCTION

von Hippel-Lindau disease (vHL disease) is a hereditary disease in which tumors and cysts develop in many organs, in association with central nervous system hemangioblastomas, pheochromocytomas, and pancreatic tumors. We herein report a case of vHL disease (type 2A) associated with bilateral pheochromocytomas, pancreatic neuroendocrine tumors (PNET), and cerebellar hemangioblastomas treated via pancreatectomy after adrenalectomy.

CASE PRESENTATION

A 51-year-old woman presented with a cerebellar tumor, bilateral hypernephroma, and pancreatic tumor detected during a medical checkup. 18F-fluorodeoxyglucose positron emission tomography-computed tomography revealed a bilateral adrenal gland tumor and a tumor in the head of the pancreas, while an abdominal computed tomography examination revealed a 30-mm tumor with strong enhancement in the head of the pancreas. Cranial magnetic resonance imaging showed a hemangioblastoma in the cerebellum. Therefore, a diagnosis of vHL disease (type 2A) was made. Her family medical history included renal cell carcinoma in her father and bilateral adrenal pheochromocytoma and spinal hemangioblastoma in her brother. A detailed examination of endocrine function showed that the adrenal mass was capable of producing catecholamine. Treatment of the pheochromocytoma was prioritized, and therefore, laparoscopic left adrenalectomy and subtotal resection of the right adrenal gland were performed. Once the postoperative steroid levels were replenished, subtotal stomach-preserving pancreatoduodenectomy was performed for the PNET. After a good postoperative course, the patient was discharged in remission on the 11th day following surgery. Histopathological examination findings indicated NET G2 (MIB-1 index 10-15%) pT3N0M0 Stage II A and microcystic serous cystadenoma throughout the resected specimen. The patient is scheduled to undergo treatment for the cerebellar hemangioblastoma.

CONCLUSION

A two-staged resection is a safe and effective treatment option for bilateral pheochromocytoma and PNET associated with vHL disease.

Association between severity of obstructive sleep apnea and glycated hemoglobin level in Japanese individuals with and without diabetes

Aim of this study was to examine the association between the severity of obstructive sleep apnea (OSA) and dysglycemia in Japanese individuals with and without type 2 diabetes (T2DM). We enrolled 115 individuals diagnosed with OSA with an apnea hypopnea-index (AHI) ≥ 20 in whom continuous positive airway pressure (CPAP) therapy was introduced (N = 115, 44 with T2DM, age 62 ± 11 years, BMI 27.0 ± 4.4 kg/m² and AHI median 36.1; interquartile range 27.2-48.1). During admission, the severity of OSA was evaluated by polysomnography, and its association with glycated hemoglobin (HbA1c) level was examined. Continuous glucose monitoring (CGM) was also conducted during the admission in 94 individuals. Apnea-hypopnea index (AHI), non-rapid eye movement (REM) AHI, minimum peripheral capillary oxygen saturation (SpO₂) and percentage of sleep time (%TST) with SpO₂ < 90% were significantly associated with HbA1c level in total and non-diabetic individuals (all p < 0.05) but not in those with T2DM, the majority of whom were treated with anti-diabetic medications. The associations of the non-REM AHI and %TST with SpO₂ < 90% with HbA1c level remained significant after adjustment for age, sex and BMI in non-diabetic and T2DM subjects treated with dietary therapy only. Mean glucose level, but not SD or coefficient of variation of glucose, assessed by CGM was significantly associated with AHI and non-REM AHI in non-diabetic subjects after adjustment for age, sex and BMI. In conclusion, the severity of OSA was associated with increased HbA1c level independently of BMI in Japanese individuals, especially in those without diabetes.

Prevalence of Cardiovascular Disease and Its Risk Factors in Primary Aldosteronism: A Multicenter Study in Japan

There have been several clinical studies examining the factors associated with cardiovascular disease (CVD) in patients with primary aldosteronism (PA); however, their results have left it unclear whether CVD is affected by the plasma aldosterone concentration or hypokalemia. We assessed the PA database established by the multicenter JPAS (Japan Primary Aldosteronism Study) and compared the prevalence of CVD among patients with PA with that among age-, sex-, and blood pressure-matched essential hypertension patients and participants with hypertension in a general population cohort. We also performed binary logistic regression analysis to determine which parameters significantly increased the odds ratio for CVD. Of the 2582 patients with PA studied, the prevalence of CVD, including stroke (cerebral infarction, cerebral hemorrhage, or subarachnoid hemorrhage), ischemic heart disease (myocardial infarction or angina pectoris), and heart failure, was 9.4% (stroke, 7.4%; ischemic heart disease, 2.1%; and heart failure, 0.6%). The prevalence of CVD, especially stroke, was higher among the patients with PA than those with essential hypertension/hypertension. Hypokalemia (K⁺ ≤3.5 mEq/L) and the unilateral subtype significantly increased adjusted odds ratios for CVD. Although aldosterone levels were not linearly related to the adjusted odds ratio for CVD, patients with plasma aldosterone concentrations ≥125 pg/mL had significantly higher adjusted odds ratios for CVD than those with plasma aldosterone concentrations <125 pg/mL. Thus, patients with PA seem to be at a higher risk of developing CVD than patients with essential hypertension. Moreover, patients with PA presenting with hypokalemia, the unilateral subtype, or plasma aldosterone concentration ≥125 pg/mL are at a greater risk of CVD and have a greater need for PA-specific treatments than others.

High Glucose Stimulates Mineralocorticoid Receptor Transcriptional Activity Through the Protein Kinase C β Signaling

Activation of mineralocorticoid receptor (MR) is shown in resistant hypertension including diabetes mellitus. Although protein kinase C (PKC) signaling is involved in the pathogenesis of diabetic complications, an association between PKC and MR is not known. Activation of PKCα and PKCβ by TPA (12-O-Tetradecanoylphorbol 13-acetate) increased MR proteins and its transcriptional activities in HEK293-MR cells. In contrast, a high glucose condition resulted in PKCβ but not PKCα activation, which is associated with elevation of MR protein levels and MR transcriptional activities. Reduction of endogenous PKCβ by siRNA decreased those levels. Interestingly, high glucose did not affect MR mRNA levels, but rather decreased ubiquitination of MR proteins. In db/db mice kidneys, levels of phosphorylated PKCβ2, MR and Sgk-1 proteins were elevated, and the administration of PKC inhibitor reversed these changes compared to db/+ mice. These data suggest that high glucose stimulates PKCβ signaling, which leads to MR stabilization and its transcriptional activities.

A case of familial dysalbuminemic hyperthyroxinemia (FDH) in Japan: FDH as a possible differential diagnosis of syndrome of inappropriate secretion of thyroid-stimulating hormone (SITSH)

Familial dysalbuminemic hyperthyroxinemia (FDH) is an autosomal dominant condition and is the most commonly inherited euthyroid hyperthyroxinemia in Caucasians. However, it is extremely rare in Asian populations. A 30-year-old Japanese woman, who was incidentally found to have apparent thyroid dysfunction, was admitted to our hospital in 2004. She had extremely elevated serum free thyroxine (FT₄), moderately elevated free triiodothyronine (FT₃), and normal thyroid-stimulating hormone (TSH). Clinical thyroid examination revealed no abnormalities other than small goiter. Anti-thyroglobulin antibody titer was positive, but titers of other anti-thyroid antibodies, including antithyroid peroxidase antibody, TSH receptor antibodies, and thyroid-stimulating antibody, were negative. Levels of FT₃, FT₄, and TSH were similar when measured by three different laboratory kits, and FT₄ was still high when measured by equilibrium dialysis. By affinity chromatography, FT₄, TT₄, and albumin were extracted to the same fraction, and the levels of FT₄ and TT₄ were extremely high. By combination of reversed phase liquid chromatography and mass spectrometry techniques, the amino acid sequence of human serum albumin was determined. The patient was found to be a heterozygote for p.R218P mutation in the gene for human serum albumin and was diagnosed as FDH. This patient, who harbored the p.R218P mutation in the albumin gene, is the fifth case report of FDH in Japan. This condition is characterized by extremely high serum FT₄ and moderately high serum FT₃ levels. Although rare, FDH should be considered in the differential diagnosis for syndrome of inappropriate secretion of TSH (SITSH) in Japan.

Clinical significance of 'cardiometabolic memory': a systematic review of randomized controlled trials

'Cardiometabolic memory' has been proposed based on clinical evidence to explain how, even after the cessation of a clinical trial, the superiority of one treatment over the outcome persists. To understand the cardiometabolic memory phenomenon, we performed a systematic review of randomized controlled trials (RCTs) using PubMed in August 2016. The search terms 'randomized controlled trial', 'post-trial follow-up' and 'diabetes, hypertension or dyslipidemia' were used, and articles published after the year 2000 were searched. We judged the memory phenomenon to be positive when the cardiovascular outcome at the end of the post-trial follow-up period in the intervention group was significantly superior even though the favorable control of a risk factor (blood glucose, blood pressure or lipid level) during the trial period was lost after the cessation of the intervention. Among 907 articles retrieved in the initial screening, 21 articles were judged as describing a positive memory phenomenon. Eight, six and seven of the articles concerned diabetes, hypertension and dyslipidemia, respectively. Transient intensive glucose lowering rather easily induced memory for the suppression of diabetic microangiopathies, while memory for the suppression of macroangiopathies tended to be first evident in the post-trial follow-up period. Transient intensive blood pressure lowering was generally effective in the formation of memory for the suppression of cardiovascular events and had an especially strong impact on risk reduction of chronic heart failure. Transient intensive LDL cholesterol lowering clearly had a long-term beneficial effect on risk reduction of cardiovascular events. Our systematic review revealed the clinical relevance of cardiometabolic memory.

Calibration and evaluation of routine methods by serum certified reference material for aldosterone measurement in blood

We attempted to study the standardization of aldosterone measurement in blood. The serum certified reference material (serum CRM) was established by spiking healthy human serum with pure aldosterone. ID-LC/MS/MS as a reference measurement procedure was performed by using the serum CRM. LC-MS/MS as a comparison method (CM) was routinely used for clinical samples, and the values with and without calibration by the serum CRM were compared. The serum CRM demonstrated similar reactivity with peripheral blood plasma as clinical samples in routine methods (RM) of RIA, ELISA, and CLEIA. In comparison between RM and CM, the results in regression analysis indicated that the range of the correlation coefficient (r) was 0.913 - 0.991, the range of y intercept was 0.9 - 67.3 pg/mL and the range of slope was 0.869 - 1.174. The values by RM in 100 - 150 pg/mL for the diagnostic level, had a significant calibration effect, and the relative difference between calibrated value in RM and result by CM was within ±20%. Furthermore, the calibrated value using the serum CRM was 10,187 pg/mL, which corresponds to measured value of 14,000 pg/mL using RIA for the adrenal venous sampling. Measured values between plasma and serum as a sample for the aldosterone measurement from clinical samples showed no significant differences. In conclusion, we succeeded to prepare the certified reference material of aldosterone for RM. Then, we can accurately calculate corrected values by using our equation for four RMs of determination of aldosterone.

Adrenal Insufficiency under Standard Dosage of Glucocorticoid Replacement after Unilateral Adrenalectomy for Cushing's Syndrome

Glucocorticoid replacement is needed for patients after adrenal surgery for Cushing's syndrome; however, the adequate dosage is not easily determined. The patient was a 62-year-old woman who has had hypertension for 5 years and presented with heart failure due to hypertrophic cardiomyopathy. She consulted with us because of general fatigue, facial edema, and muscle weakness and was diagnosed with Cushing's syndrome. A laparoscopic left adrenalectomy was performed, standard dosage of postoperative replacement was administered, and she was discharged with 30 mg/day of hydrocortisone (cortisol). However, she suffered from loss of appetite and was transferred to an emergency unit with the symptoms of adrenal insufficiency on postoperative day 15. After initial hydrocortisone replacement with 200 mg/day, the dosage was gradually decreased during hospitalization; however, reduction of hydrocortisone dosage lower than 60 mg/day was difficult because of nausea and fatigue. Her circadian cortisol profile after hydrocortisone administration showed delayed and lowered peaks, which suggested that hydrocortisone absorption in the intestine was impaired. Therefore, complicated heart failure may have led to the adrenal insufficiency in the patient. In such cases, we should consider postoperative administration of more than the standard dosage of hydrocortisone to avoid adrenal insufficiency after surgery for Cushing's syndrome.

The learning curve of laparoendoscopic single-site adrenalectomy: an analysis of over 100 cases

BACKGROUND

Recently, laparoendoscopic single-site adrenalectomy (LESS-A) has been developed as an alternative treatment for adrenal tumors. Although LESS-A is more technically complex than conventional laparoscopic adrenalectomy, its learning curve and the factors associated with poor surgical outcomes are poorly understood. We analyzed the learning curve of LESS-A and attempted to identify risk factors associated with worse surgical outcomes.

METHODS

We identified 103 patients who underwent LESS-A [performed by the same surgeon (A.M.)] from 2009 to 2015. The learning curve was analyzed using the moving average method (the 10-case moving average), and we assessed potential risk factors for a prolonged pneumoperitoneum time.

RESULTS

The learning curve stabilized at 30 cases. The cases were divided into two groups, the learning stage (LS) (cases 1-29) and master stage (MS) (cases 30-103) groups. The percentage of females and the frequency of previous abdominal surgery were higher in the LS group (p = 0.022 and 0.001, respectively). In the LS group, the mean pneumoperitoneum time was 92 ± 35 min, which was significantly longer than the equivalent value for the MS group (55 ± 18 min, p < 0.001). In the LS group, univariate analysis revealed that tumor size (≥50 mm) and the visceral fat area (VFA)/total fat area (TFA) ratio (≥0.49) were significantly associated with a prolonged pneumoperitoneum time (p = 0.046 and 0.046, respectively). In the multivariate analysis, tumor size and the VFA/TFA ratio were confirmed to be associated with a prolonged pneumoperitoneum time (p = 0.029 and 0.029, odds ratio 20.83 and 20.83, respectively). On the other hand, none of the examined factors were found to be associated with a prolonged pneumoperitoneum time in the MS group.

CONCLUSIONS

LESS-A was performed safely in most cases. However, surgeons who are learning the LESS-A procedure need to pay attention to tumor size and visceral obesity.

Case Report: Nodule Development From Subcapsular Aldosterone-Producing Cell Clusters Causes Hyperaldosteronism

CONTEXT

We previously reported that the human adrenal cortex remodels to form subcapsular aldosterone-producing cell clusters (APCCs). Some APCCs were recently found to carry aldosterone-producing adenoma (APA)-associated somatic mutations in ion channel/pump genes, which implied that APCCs produce aldosterone autonomously and are an origin of APA. However, there has been no report describing an APCC-to-APA transitional lesion.

CASE DESCRIPTION

A histological examination revealed unilateral multiple adrenocortical micronodules in the adrenals of two patients with primary aldosteronism (PA). Based on immunohistochemistry for aldosterone synthase, some of the micronodules were identified as possible APCC-to-APA transitional lesions (pAATLs; a tentative term used in this manuscript), which consisted of a subcapsular APCC-like portion and an inner micro-APA-like (mAPA-like) portion without an apparent histological border. Genomic DNA samples prepared from pAATL histological sections were analyzed by next-generation sequencing for the known APA-associated mutations. The mAPA-like portions from two of the three large pAATLs examined harbored mutations (KCNJ5 [p.G151R] in pAATL 3 and ATP1A1 [p.L337M] in pAATL 7), whereas their corresponding APCC-like portions did not, suggesting their role in the formation of mAPA. Another lesion carried novel mutations in ATP1A1 (p.Ile322_Ile325del and p.Ile327Ser) in both the mAPA-like and APCC-like portions, thereby supporting these portions having a clonal origin.

CONCLUSION

A novel aldosterone-producing pathology, pAATL that causes unilateral PA, was detected in the adrenals of two patients. Next-generation sequencing analyses of the large pAATLs suggested that the introduction of APA-associated mutations in the ion channel/pump genes may be involved in the development of mAPA from existing APCCs.

Effect of KCNJ5 mutations on gene expression in aldosterone-producing adenomas and adrenocortical cells

CONTEXT

Primary aldosteronism is a heterogeneous disease that includes both sporadic and familial forms. A point mutation in the KCNJ5 gene is responsible for familial hyperaldosteronism type III. Somatic mutations in KCNJ5 also occur in sporadic aldosterone producing adenomas (APA).

OBJECTIVE

The objective of the study was to define the effect of the KCNJ5 mutations on gene expression and aldosterone production using APA tissue and human adrenocortical cells.

METHODS

A microarray analysis was used to compare the transcriptome profiles of female-derived APA samples with and without KCNJ5 mutations and HAC15 adrenal cells overexpressing either mutated or wild-type KCNJ5. Real-time PCR validated a set of differentially expressed genes. Immunohistochemical staining localized the KCNJ5 expression in normal adrenals and APA.

RESULTS

We report a 38% (18 of 47) prevalence of KCNJ5 mutations in APA. KCNJ5 immunostaining was highest in the zona glomerulosa of NA and heterogeneous in APA tissue, and KCNJ5 mRNA was 4-fold higher in APA compared with normal adrenals (P < 0.05). APA with and without KCNJ5 mutations displayed slightly different gene expression patterns, notably the aldosterone synthase gene (CYP11B2) was more highly expressed in APA with KCNJ5 mutations. Overexpression of KCNJ5 mutations in HAC15 increased aldosterone production and altered expression of 36 genes by greater than 2.5-fold (P < 0.05). Real-time PCR confirmed increases in CYP11B2 and its transcriptional regulator, NR4A2.

CONCLUSIONS

KCNJ5 mutations are prevalent in APA, and our data suggest that these mutations increase expression of CYP11B2 and NR4A2, thus increasing aldosterone production.