Cardiometabolic Disease Burden and Steroid Excretion in Benign Adrenal Tumors : A Cross-Sectional Multicenter Study.

BACKGROUND: Benign adrenal tumors are commonly discovered on cross-sectional imaging. Mild autonomous cortisol secretion (MACS) is regularly diagnosed, but its effect on cardiometabolic disease in affected persons is ill defined. OBJECTIVE: To determine cardiometabolic disease burden and steroid excretion in persons with benign adrenal tumors with and without MACS. DESIGN: Cross-sectional study. SETTING: 14 endocrine secondary and tertiary care centers (recruitment from 2011 to 2016). PARTICIPANTS: 1305 prospectively recruited persons with benign adrenal tumors. MEASUREMENTS: Cortisol excess was defined by clinical assessment and the 1-mg overnight dexamethasone-suppression test (serum cortisol: <50 nmol/L, nonfunctioning adrenal tumor [NFAT]; 50 to 138 nmol/L, possible MACS [MACS-1]; >138 nmol/L and absence of typical clinical Cushing syndrome [CS] features, definitive MACS [MACS-2]). Net steroid production was assessed by multisteroid profiling of 24-hour urine by tandem mass spectrometry. RESULTS: Of the 1305 participants, 49.7% had NFAT (n = 649; 64.1% women), 34.6% had MACS-1 (n = 451; 67.2% women), 10.7% had MACS-2 (n = 140; 73.6% women), and 5.0% had CS (n = 65; 86.2% women). Prevalence and severity of hypertension were higher in MACS-2 and CS than NFAT (adjusted prevalence ratios [aPRs] for hypertension: MACS-2, 1.15 [95% CI, 1.04 to 1.27], and CS, 1.37 [CI, 1.16 to 1.62]; aPRs for use of ≥3 antihypertensives: MACS-2, 1.31 [CI, 1.02 to 1.68], and CS, 2.22 [CI, 1.62 to 3.05]). Type 2 diabetes was more prevalent in CS than NFAT (aPR, 1.62 [CI, 1.08 to 2.42]) and more likely to require insulin therapy for MACS-2 (aPR, 1.89 [CI, 1.01 to 3.52]) and CS (aPR, 3.06 [CI, 1.60 to 5.85]). Urinary multisteroid profiling revealed an increase in glucocorticoid excretion from NFAT over MACS-1 and MACS-2 to CS, whereas androgen excretion decreased. LIMITATIONS: Cross-sectional design; possible selection bias. CONCLUSION: A cardiometabolic risk condition, MACS predominantly affects women and warrants regular assessment for hypertension and type 2 diabetes. PRIMARY FUNDING SOURCE: Diabetes UK, the European Commission, U.K. Medical Research Council, the U.K. Academy of Medical Sciences, the Wellcome Trust, the U.K. National Institute for Health Research, the U.S. National Institutes of Health, the Claire Khan Trust Fund at University Hospitals Birmingham Charities, and the Mayo Clinic Foundation for Medical Education and Research.

ENDOSCOPIC ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION IN THE DIAGNOSIS OF ADRENAL METASTASIS IN A HIGH-RISK POPULATION.

OBJECTIVE: While the left adrenal gland is readily accessible via endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), data regarding the utility of EUS-FNA in the diagnosis of adrenal lesions remain limited. We aimed to ( 1) describe the clinical context, adverse event rate, and diagnostic performance of EUS-FNA, and ( 2) compare the safety profile and diagnostic accuracy of EUS-FNA with percutaneous adrenal biopsy. METHODS: Single-center, retrospective cohort study. Medical records of patients who underwent adrenal EUS-FNA from 2005-2016 were reviewed. Biopsy outcomes were evaluated using a predefined reference standard. Results were compared to patients who underwent percutaneous biopsy (n = 419; 1994-2014) at the same institution. RESULTS: A total of 121 patients underwent EUS-FNA of 122 adrenal lesions (left [n = 121]; right [n = 1]; mean lesion size, 1.8 cm). Cytology was positive for malignancy in 35 (29%), suspicious for malignancy in 1 (1%), atypical in 1 (1%), negative for malignancy in 81 (66%), and nondiagnostic in 4 (3%). No adverse events were reported. EUS-FNA diagnosed metastasis with a sensitivity of 100%, specificity of 97.4%, positive predictive value of 91.7%, and negative predictive value of 100%. When compared to percutaneous biopsy, lesion size (1.8 cm vs. 3.7 cm; P<.001) and biopsy site (99% vs. 62% left adrenal; P<.001) were significantly different. EUS-FNA adverse event rate was lower than percutaneous biopsy (0% vs. 4%; P = .024), but nondiagnostic rates were similar (3.3% vs. 4.8%; P = .48). CONCLUSION: EUS-FNA is a sensitive technique to sample adrenal lesions in patients at high risk for adrenal metastasis with fewer adverse events compared to percutaneous biopsy. ABBREVIATIONS: CI = confidence interval CT = computed tomography EUS-FNA = endoscopic ultrasound-guided fine-needle aspiration NPV = negative predictive value PPV = positive predictive value TUS = transabdominal ultra-sound.

Challenges in the postsurgical recovery of cushing syndrome: glucocorticoid withdrawal syndrome.

Glucocorticoid withdrawal syndrome is a challenging clinical phenomenon that can complicate the postsurgical recovery of Cushing syndrome. It is characterized by physical tolerance and dependence to supraphysiologic glucocorticoid exposure during active Cushing syndrome followed by the abrupt decline in cortisol levels after surgical treatment. The symptoms of glucocorticoid withdrawal often overlap with those of postoperative adrenal insufficiency and can be difficult for patients to cope with and for clinicians to treat. This mini review will discuss the clinical characteristics, pathophysiology, and management of glucocorticoid withdrawal syndrome while highlighting recent data in the field.

Clinical and Imaging Presentations are Associated with Function in Incidental Adrenocortical Adenomas - a Retrospective Cohort Study.

OBJECTIVE: To assess whether clinical and imaging characteristics predict hormonal subtype, growth, and adrenalectomy for incidental adrenal cortical adenomas (ACA). DESIGN: Single center cohort study. METHODS: Consecutive adult patients with incidental ACA diagnosed between 2000 and 2016. RESULTS: Of 1516 patients with incidental ACA (median age 59 years, 62% women), 699 (46%) had nonfunctioning adenomas (NFA), 482 (31%) had mild autonomous cortisol secretion (MACS), 62 (4%) had primary aldosteronism (PA), 39 (3%) had Cushing syndrome (CS), 18 (1%) had PA and MACS (PA-MACS), and 226 (15%) had incomplete workup. Age, sex, tumor size, and tumor laterality, but not unenhanced computed tomography Hounsfield units (HU), were associated with hormonal subtypes. In a multivariable analysis, ≥1cm growth was associated with younger age (odds ratio per 5-year increase, OR=0.8, P=0.0047) and longer imaging follow-up (OR=1.2 per year, P<.0001). Adrenalectomy was performed in 355 (23%) patients, including 38% of MACS and 15% of NFA. Adrenalectomy for NFA and MACS was more common in younger patients (OR=0.79 per 5-year increase, P=0.002), larger initial tumor size (OR=2.3 per 1-cm increase, P<.0001), ≥1cm growth (OR=15.3, P<.0001), and higher post-dexamethasone cortisol (OR=6.6 for >5 vs <1.8 mcg/dL, P=0.002). CONCLUSIONS: Age, sex, tumor size, and laterality were associated with ACA hormonal subtype and can guide diagnosis and management. Tumor growth was more common with younger age and longer follow-up. Unenhanced HU did not predict hormonal subtype or growth. Adrenalectomy for MACS and NFA was mainly performed in younger patients with larger tumor size, growth, and elevated post-dexamethasone cortisol.

A New Approach - Home Waking Salivary Cortisone to Screen for Adrenal Insufficiency.

Adrenal insufficiency is a common and potentially life-threatening endocrine disorder that can be drug induced or endogenous and of adrenal (primary) or pituitary/hypothalamic (secondary/tertiary) origin.1,2 Of particular concern in drug-induced disease is the patient with glucocorticoid- or opioid-induced adrenal insufficiency. Adrenal insufficiency of any cause is typically diagnosed biochemically with a subnormal morning serum cortisol (the circadian, awakening peak) and serum dehydroepiandrosterone sulfate, followed by or simultaneously with an assessment of the acute (30 and 60 minutes) serum cortisol response to injected synthetic corticotropin (ACTH[1-24]), if clinically indicated.

Determinants of muscle function and health-related quality of life in patients with endogenous hypercortisolism: a cross-sectional study.

OBJECTIVE: Prospective data on determinants of muscle strength impairment and quality of life in patients with various subtypes and severity of endogenous hypercortisolism are lacking. DESIGN: Single-center cross-sectional study, 2019 to 2022. METHODS: Patients with Cushing syndrome (CS) and mild autonomous cortisol secretion (MACS) were assessed with clinical and biochemical severity scores, muscle function (nondominant hand grip strength and sit-to-stand test), and quality of life (Short Form-36 [SF36] and CushingQoL). Referent subjects were recruited from the local population undergoing abdominal imaging for reasons other than suspected adrenal disorder. RESULTS: Of 164 patients, 81 (49%) had MACS, 14 (9%) had adrenal CS, 60 (37%) had pituitary CS, and 9 (5%) had ectopic CS. Median age was 53 years (interquartile range: 42-63 years), and 126 (77%) were women. The SF36 mental component score was similarly low in patients with MACS vs CS, but physical component score was lower in CS when compared to MACS (mean of 34.0 vs 40.5, P = .001). Compared to MACS, patients with CS had lower scores on the standardized CushingQoL (mean of 47.1 vs 34.2, P < .001). Compared to referent subjects, patients with MACS demonstrated reduced muscle strength, similar to patients with CS (mean sit to stand Z-score of -0.47 vs -0.54, P = .822). Clinical severity (r = -0.22, P = .004) but not biochemical severity was associated with sit-to-stand test performance. CONCLUSIONS: Both patients with overt CS and MACS demonstrate reduced muscle strength and low quality of life. The clinical severity score utilized is associated with both physical and psychosocial components of CushingQoL and with the physical component of SF36.

Risk of dementia and psychiatric or sleep disorders after diagnosis of adrenal adenomas: a population-based cohort study.

OBJECTIVE: Adrenal adenomas are commonly encountered in clinical practice. To date, population-based data on their impact on cognition, mental health, and sleep are lacking. We aimed to study possible associations between adrenal adenomas and dementia, psychiatric or sleep disorders. DESIGN: Population-based cohort study, Olmsted County, MN, 1995-2017. METHODS: Patients with adrenal adenoma and absent overt hormone excess were age- and sex-matched 1:1 to a referent person without adrenal adenoma. Outcomes were baseline and incident diagnoses of dementia, psychiatric or sleep disorders, assessed using ICD codes. RESULTS: Of 1004 patients with adrenal adenomas, 582 (58%) were women, and median age at diagnosis was 63 years. At baseline, and after adjusting for age, sex, education, BMI, and tobacco use, patients with adenoma had higher odds of depression (adjusted odds ratio, aOR: 1.3, 95% CI, 1.1-1.6), anxiety (aOR: 1.4, 95% CI, 1.1-1.8), and substance abuse (aOR: 2.4, 95% CI, 1.7-3.4) compared to referents. During a median follow-up of 6.8 years, and after adjusting for age, sex, socioeconomic status, BMI, tobacco, and substance abuse, patients demonstrated a higher risk of psychiatric and sleep disorders [adjusted hazard ratio (95% CI)]: depression [1.7 (1.3-2.2)], anxiety [1.4, CI (1.1-1.7)], insomnia [1.4 (1.0-1.9)], sleep-related breathing disorders [1.5 (1.1-1.9)], hypersomnias [2.1 (1.0-4.2)], parasomnias [2.1 (1.0-4.2)], and sleep-related movement disorders [1.5 (1.0-2.1)], but not dementia. CONCLUSIONS: Patients with adenomas demonstrate a higher incidence of psychiatric and sleep disorders, possibly due to the underlying subtle increase in cortisol secretion.

Glucocorticoid withdrawal syndrome following surgical remission of endogenous hypercortisolism: a longitudinal observational study.

OBJECTIVE: Glucocorticoid withdrawal syndrome (GWS) is a scarcely studied phenomenon that complicates the recovery following surgical remission of hypercortisolism. We aimed to characterize the presence and trajectory of glucocorticoid withdrawal symptoms in the postoperative period and to determine presurgical predictors of GWS severity. DESIGN: Longitudinal observational study. METHODS: Glucocorticoid withdrawal symptoms were prospectively evaluated weekly for the first 12 weeks following surgical remission of hypercortisolism. Quality of life (CushingQoL and Short-Form-36) and muscle function (hand grip strength and sit-to-stand test) were assessed at the baseline and at 12 weeks after surgery. RESULTS: Prevalent symptoms were myalgias and arthralgias (50%), fatigue (45%), weakness (34%), sleep disturbance (29%), and mood changes (19%). Most symptoms persisted, while myalgias, arthralgias, and weakness worsened during weeks 5-12 postoperatively. At 12 weeks after surgery, normative hand grip strength was weaker than at baseline (mean Z-score delta -0.37, P = .009), while normative sit-to-stand test performance improved (mean Z-score delta 0.50, P = .013). Short-Form-36 Physical Component Summary score worsened (mean delta -2.6, P = .015), but CushingQoL score improved (mean delta 7.8, P < .001) at 12 weeks compared to baseline. Cushing syndrome (CS) clinical severity was predictive of postoperative GWS symptomology. CONCLUSION: Glucocorticoid withdrawal symptoms are prevalent and persistent following surgical remission of hypercortisolism with baseline CS clinical severity predictive of postoperative GWS symptom burden. Differential changes observed in muscle function and quality of life in the early postoperative period may reflect the competing influences of GWS and recovery from hypercortisolism.

High prevalence of frailty in patients with adrenal adenomas and adrenocortical hormone excess: a cross-sectional multi-centre study with prospective enrolment.

OBJECTIVE: Frailty, characterized by multi-system decline, increases vulnerability to adverse health outcomes and can be measured using Frailty Index (FI). We aimed to assess the prevalence of frailty in patients with adrenal disorders (based on hormonal sub-type) and examine association between FI and performance-based measures of physical function. DESIGN: Multi-centre, cross-sectional study (March 2019-August 2022). METHODS: Adult patients with adrenal disorders (non-functioning adrenal adenomas [NFA], mild autonomous cortisol secretion [MACS], Cushing syndrome [CS], primary aldosteronism [PA]) and referent subjects without adrenal disorders completed a questionnaire encompassing 47 health variables (comorbidities, symptoms, daily living activities). FI was calculated as the average score of all variables and frailty defined as FI ≥ 0.25. Physical function was assessed with hand grip, timed up-and-go test, chair rising test, 6-minute walk test, and gait speed. RESULTS: Compared to referent subjects (n = 89), patients with adrenal disorders (n = 520) showed increased age, sex, and body mass index-adjusted prevalence of frailty (CS [odds ratio-OR 19.2, 95% confidence interval-CI 6.7-70], MACS [OR 12.5, 95% CI 4.8-42.9], PA [OR 8.4, 95% CI 2.9-30.4], NFA [OR 4.5, 95% CI 1.7-15.9]). Prevalence of frailty was similar to referent subjects when post-dexamethasone cortisol was <28 nmol/L and was higher when post-dexamethasone cortisol was 28-50 nmol/L (OR 4.6, 95% CI 1.7-16.5). FI correlated with all measures of physical function (P < .001). CONCLUSIONS: Whilst frailty prevalence was highest in patients with adrenocortical hormone excess, even patients with NFA demonstrated an increased prevalence compared to the referent population. Future longitudinal studies are needed to evaluate the impact of various management strategies on frailty.

The metabolic phenotype of patients with primary aldosteronism: impact of subtype and sex - a multicenter-study of 3566 Caucasian and Asian subjects.

Background: Accumulating evidence suggests that primary aldosteronism (PA) is associated with several features of the metabolic syndrome, in particular with obesity, type 2 diabetes mellitus, and dyslipidemia. Whether these manifestations are primarily linked to aldosterone-producing adenoma (APA) or bilateral idiopathic hyperaldosteronism (IHA) remains unclear. The aim of the present study was to investigate differences in metabolic parameters between APA and IHA patients and to assess the impact of treatment on these clinical characteristics. Methods: We conducted a retrospective multicenter study including 3566 patients with APA or IHA of Caucasian and Asian origin. We compared the prevalence of metabolic disorders between APA and IHA patients at the time of diagnosis and 1-year post-intervention, with special references to sex differences. Furthermore, correlations between metabolic parameters and plasma aldosterone, renin, or plasma cortisol levels after 1 mg dexamethasone (DST) were performed. Results: As expected, APA patients were characterized by higher plasma aldosterone and lower serum potassium levels. Only female IHA patients demonstrated significantly worse metabolic parameters than age-matched female APA patients, which were associated with lower cortisol levels upon DST. One-year post-intervention, female adrenalectomized patients showed deterioration of their lipid profile, when compared to patients treated with mineralocorticoid receptor antagonists. Plasma aldosterone levels negatively correlated with the BMI only in APA patients. Conclusions: Metabolic alterations appear more prominent in women with IHA. Although IHA patients have worse metabolic profiles, a correlation with cortisol autonomy is documented only in APAs, suggesting an uncoupling of cortisol action from metabolic traits in IHA patients.

Risk of bone fractures after the diagnosis of adrenal adenomas: a population-based cohort study.

OBJECTIVE: Several small studies reported increased prevalence and incidence of asymptomatic vertebral fractures in patients with non-functioning adrenal adenomas and adenomas with mild autonomous cortisol secretion. However, the risk of symptomatic fractures at vertebrae, and at other sites remains unknown. Our objective was to determine the prevalence and incidence of symptomatic site-specific fractures in patients with adrenal adenomas. DESIGN: Population-based cohort study, Olmsted County, Minnesota, USA, 1995-2017. METHODS: Participants were the patients with adrenal adenoma and age/sex-matched referent subjects. Patients with overt hormone excess were excluded. Main outcomes measures were prevalence and incidence of bone fractures. RESULTS: Of 1004 patients with adrenal adenomas, 582 (58%) were women, and median age at diagnosis was 63 years (20-96). At the time of diagnosis, patients had a higher prevalence of previous fractures than referent subjects (any fracture: 47.9% vs 41.3%, P = 0.003, vertebral fracture: 6.4% vs 3.6%, P = 0.004, combined osteoporotic sites: 16.6% vs 13.3%, P = 0.04). Median duration of follow-up was 6.8 years (range: 0-21.9 years). After adjusting for age, sex, BMI, tobacco use, prior history of fracture, and common causes of secondary osteoporosis, patients with adenoma had hazard ratio of 1.27 (95% CI: 1.07-1.52) for developing a new fracture during follow up when compared to referent subjects. CONCLUSIONS: Patients with adrenal adenomas have higher prevalence of fractures at the time of diagnosis and increased risk to develop new fractures when compared to referent subjects.

Cardiometabolic Outcomes and Mortality in Patients with Adrenal Adenomas in a Population-based Setting.

CONTEXT: While adrenal adenomas have been linked with cardiovascular morbidity in convenience samples of patients from specialized referral centers, large-scale population-based data are lacking. OBJECTIVE: To determine the prevalence and incidence of cardiometabolic disease and assess mortality in a population-based cohort of patients with adrenal adenomas. DESIGN: Population-based cohort study. SETTING: Olmsted County, Minnesota, USA. PATIENTS: Patients diagnosed with adrenal adenomas without overt hormone excess and age- and sex-matched referent subjects without adrenal adenomas. MAIN OUTCOME MEASURE: Prevalence, incidence of cardiometabolic outcomes, mortality. RESULTS: (Adrenal adenomas were diagnosed in 1004 patients (58% women, median age 63 years) from 1/01/1995 to 12/31/2017. At baseline, patients with adrenal adenomas were more likely to have hypertension [adjusted odds ratio (aOR) 1.96, 95% CI 1.58-2.44], dysglycemia (aOR 1.63, 95% CI 1.33-2.00), peripheral vascular disease (aOR 1.59, 95% CI 1.32-2.06), heart failure (aOR 1.64, 95% CI 1.15-2.33), and myocardial infarction (aOR 1.50, 95% CI 1.02-2.22) compared to referent subjects. During median follow-up of 6.8 years, patients with adrenal adenomas were more likely than referent subjects to develop de novo chronic kidney disease [adjusted hazard ratio (aHR) 1.46, 95% CI 1.14-1.86], cardiac arrhythmia (aHR 1.31, 95% CI 1.08-1.58), peripheral vascular disease (aHR 1.28, 95% CI 1.05-1.55), cardiovascular events (aHR 1.33, 95% CI 1.01-1.73), and venous thromboembolic events (aHR 2.15, 95% CI 1.48-3.13). Adjusted mortality was similar between the 2 groups. CONCLUSION: Adrenal adenomas are associated with an increased prevalence and incidence of adverse cardiometabolic outcomes in a population-based cohort.

Diagnostic Accuracy of Dehydroepiandrosterone Sulfate and Corticotropin in Autonomous Cortisol Secretion.

Autonomous cortisol secretion (ACS) affects up to 50% of patients with adrenal adenomas. Despite the limited evidence, clinical guidelines recommend measurement of serum concentrations of dehydroepiandrosterone-sulfate (DHEA-S) and corticotropin (ACTH) to aid in the diagnosis of ACS. Our objective was to determine the accuracy of serum concentrations of DHEA-S and ACTH in diagnosing ACS. We conducted a retrospective single center study of adults with adrenal adenoma evaluated between 2000-2020. Main outcome measure was diagnostic accuracy of DHEA-S and ACTH. ACS was defined as post-dexamethasone cortisol >1.8 mcg/dL. Of 468 patients, ACS was diagnosed in 256 (55%) patients with a median post-DST cortisol of 3.45 mcg/dL (range, 1.9-32.7). Patients with ACS demonstrated lower serum concentrations of DHEA-S (35 vs. 87.3 mcg/dL, p < 0.0001) and ACTH (8.3 vs. 16 pg/mL, p < 0.0001) compared to patients with non-functioning adrenal tumors (NFAT). Serum DHEA-S concentration <40 mcg/dL diagnosed ACS with 84% specificity and 81% PPV, while serum ACTH concentration <10 pg/mL diagnosed ACS with 75% specificity and 78% PPV. The combination of serum concentrations of DHEA-S <40 mcg/dL and ACTH <10 pg/mL diagnosed ACS with the highest accuracy with 92% specificity and 87% PPV. Serum concentrations of DHEA-S and ACTH provide additional value in diagnosing ACS.

Adrenal biopsy: performance and use.

The widespread use of cross-sectioning abdominal imaging in recent years has led to the increased detection of adrenal masses. In each case, determining whether a newly identified adrenal mass is benign or malignant is essential for management, but can be challenging. A significant proportion of adrenal lesions remain indeterminate after initial evaluation due to limitations of current imaging modalities. Adrenal biopsy can be considered for further diagnostic workup in select cases, particularly in patients with an active or previously diagnosed extra-adrenal malignancy. In this review, we describe the various types of image-guided adrenal biopsy, including percutaneous and endoscopic techniques, highlight the utility of adrenal biopsy in various clinical scenarios, and, examine the diagnostic performance and adverse event rate of the procedure. Finally, we outline a suggested algorithm for the use of adrenal biopsy in the evaluation of an adrenal mass.

Cushing syndrome: uncovering Carney complex due to novel PRKAR1A mutation.

Carney complex (CNC) is a rare multiple neoplasia syndrome characterized by spotty pigmentation of the skin and mucosa in association with various non-endocrine and endocrine tumors, including primary pigmented nodular adrenocortical disease (PPNAD). A 20-year-old woman was referred for suspected Cushing syndrome. She had signs of cortisol excess as well as skin lentigines on physical examination. Biochemical investigation was suggestive of corticotropin (ACTH)-independent Cushing syndrome. Unenhanced computed tomography scan of the abdomen did not reveal an obvious adrenal mass. She subsequently underwent bilateral laparoscopic adrenalectomy, and histopathology was consistent with PPNAD. Genetic testing revealed a novel frameshift pathogenic variant c.488delC/p.Thr163MetfsX2 (ClinVar Variation ID: 424516) in the PRKAR1A gene, consistent with clinical suspicion for CNC. Evaluation for other clinical features of the complex was unrevealing. We present a case of PPNAD-associated Cushing syndrome leading to the diagnosis of CNC due to a novel PRKAR1A pathogenic variant. Learning points: PPNAD should be considered in the differential for ACTH-independent Cushing syndrome, especially when adrenal imaging appears normal. The diagnosis of PPNAD should prompt screening for CNC. CNC is a rare multiple neoplasia syndrome caused by inactivating pathogenic variants in the PRKAR1A gene. Timely diagnosis of CNC and careful surveillance can help prevent potentially fatal complications of the disease.