Increased prevalence of heterozygous 21-OH germline mutations in patients with adrenal incidentalomas

Intrafamilial Phenotypic Variability and Consequences of Non-Compliance with Treatment in Congenital Adrenal Hyperplasia and Congenital Hypothyroidism within a Single Family

BACKGROUND

Coexistence of congenital adrenal hyperplasia (CAH) and congenital hypothyroidism (CH) due to TG mutation in the same non-consanguineous family is rare.

CASE SERIES

We report 4 siblings born to unrelated parents, the father being an asymptomatic carrier of homozygous p.V281L and heterozygous p.I172N CYP21A2 mutations. Sibling 1 had salt-wasting CAH (CYP21A2 genotype Intron 2 splice/p.I172N and p.V281L). She also had CH (TG genotype p.R296/ p.T1416Rfs*30) and learning difficulties. Poor compliance and morbid obesity resulted in short stature, precocious puberty, hirsutism, amenorrhoea, insulin insensitivity and a possible adrenal adenoma. Sibling 3 (CYP21A2 and TG genotype similar to sibling 1) is a boy presenting with salt-wasting CAH, CH, and developmental delay. He was overweight and underwent precocious puberty. Although siblings 2 and 4 (both females) share the same CYP21A2 genotype (Intron 2 splice/p.V281L), the former only had biochemical evidence of CAH, while the latter presented at 9.8 years of age with a history of pubarche at 7 years and advanced bone age.

CONCLUSIONS

We report the unusual occurrence of 2 rare autosomal recessive diseases, CAH and CH. Our cases highlight the phenotypic variability of CAH and CH due to TG mutations, even within a single family, and illustrate the importance of optimal disease control.
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Clinical perspectives in congenital adrenal hyperplasia due to 11β-hydroxylase deficiency

Congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency is a rare autosomal recessive genetic disorder. It is caused by reduced or absent activity of 11β-hydroxylase (CYP11B1) enzyme and the resultant defects in adrenal steroidogenesis. The most common clinical features of 11 beta-hydroxylase deficiency are ambiguous genitalia, accelerated skeletal maturation and resultant short stature, peripheral precocious puberty and hyporeninemic hypokalemic hypertension. The biochemical diagnosis is based on raised serum 11-deoxycortisol and 11-deoxycorticosterone levels together with increased adrenal androgens. More than 100 mutations in CYP11B1 gene have been reported to date. The level of in-vivo activity of CYP11B1 relates to the degree of severity of 11 beta-hydroxylase deficiency. Clinical management of 11 beta-hydroxylase deficiency can pose a challenge to maintain adequate glucocorticoid dosing to suppress adrenal androgen excess while avoiding glucocorticoid-induced side effects. The long-term outcomes of clinical and surgical management are not well studied. This review article aims to collate the current available data about 11 beta-hydroxylase deficiency and its management.

Biochemical and genetic diagnosis of 21-hydroxylase deficiency

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is caused by mutations in the CYP21A2 gene and is often fatal in its classic forms if not treated with glucocorticoids. In contrast, non-classic CAH (NCCAH), with a prevalence from 0.1 % up to a few percentages in certain ethnic groups, only results in mild partial cortisol insufficiency and patients survive without treatment. Most NCCAH cases are never identified, but unnecessary suffering due to hyperandrogenism, especially in females, can be avoided by a correct diagnosis. A 17-hydroprogesterone (17OHP) level above 300 nmol/L indicates classic CAH while 30-300 nmol/L in adult males or females (follicular phase or if anovulatoric) indicates NCCAH. The gold standard for diagnosing NCCAH is the ACTH stimulation test. Deletion, large gene conversions, and nine microconversion-derived mutations are the most common CYP21A2 mutations. However, almost 200 rare mutations have been described. Since there is a good genotype-phenotype relationship, genotyping provides valuable diagnostic, as well as prognostic information. Neonatal screening for CAH is now performed in an increasing number of countries with the main goal of reducing mortality and morbidity due to salt-losing adrenal crises in the newborn period. In addition, screening may shorten the time to diagnosis in virilized girls. Neonatal screening misses some patients with milder classic CAH and most NCCAH cases. In conclusion, diagnosing classic CAH is life-saving, but diagnosing NCCAH is also important to prevent unnecessary suffering.

Nonclassic congenital adrenal hyperplasia due to 21-hydroxylase deficiency: clinical presentation, diagnosis, treatment, and outcome

Nonclassic congenital adrenal hyperplasia (NCAH) is one of the most frequent autosomal recessive disorders in man with a prevalence ranging from 0.1 % in Caucasians up to a few percent in certain ethnic groups. Most cases are never diagnosed due to very mild symptoms, misdiagnosing as polycystic ovary syndrome, or ignorance. In contrast to classic CAH, patients with NCAH present with mild partial cortisol insufficiency and hyperandrogenism and will survive without any treatment. Undiagnosed NCAH may result in infertility, miscarriages, oligomenorrhea, hirsutism, acne, premature pubarche, testicular adrenal rest tumors, adrenal tumors, and voice problems among other symptoms. A baseline measurement of 17-hydroxyprogesterone can be used for diagnosis, but the ACTH stimulation test with measurement of 17-hydroxyprogesterone is regarded as the golden standard. The diagnosis can be verified by CYP21A2 mutation analysis. Treatment is symptomatic and usually with glucocorticoids alone. The lowest possible glucocorticoid dose should be used. Long-term treatment with glucocorticoids will improve the symptoms but will also result in iatrogenic cortisol insufficiency and may also lead to long-term complications such as obesity, insulin resistance, hypertension, osteoporosis, and fractures. Although the complications seen in NCAH patients have been assumed to be related to the glucocorticoid treatment, some may, in fact, be associated with prolonged hyperandrogenism. Different risk factors and negative consequences should be monitored regularly in an attempt to improve the clinical outcome. More research is needed in this relatively common disorder.

CLINICAL OUTCOMES IN ADRENAL INCIDENTALOMA: EXPERIENCE FROM ONE CENTER

OBJECTIVE

To investigate the outcome in patients with adrenal incidentaloma (AI).

METHODS

A retrospective evaluation of 637 patients with AI referred to a tertiary center over 8 years. Radiologic and hormonal evaluations were performed at baseline. Follow-up imaging was carried out if necessary, and hormonal evaluation was performed at 24 months according to national guidelines.

RESULTS

The mean age was 62.7 ± 11.6 years, and the mean AI size was 25.3 ± 17.0 mm at presentation. Hormonal evaluation revealed that 85.4% of all tumors were nonfunctioning adenomas, 4.1% subclinical Cushing syndrome (SCS), 1.4% pheochromocytoma, 1.4% primary hyperaldosteronism, 0.8% Cushing syndrome, 0.6% adrenocortical carcinoma, 0.3% congenital adrenal hyperplasia, 2.2% metastasis to adrenals, and 3.8% other lesions of benign origin. Bilateral tumors were found in 11%, and compared to unilateral tumors, SCS was more prevalent. Only 2 cases were reclassified during follow-up, both as SCS, but neither had had a dexamethasone suppression test performed at initial work-up. In patients diagnosed with an adrenal metastasis, 92.9% were deceased within 2 years. Excluding those with malignant tumors, 12.9% of patients died during the study period of up to 11 years due to other causes than adrenal.

CONCLUSION

Most AIs were benign, but a small fraction of tumors were functional and malignant. The prognosis of patients with adrenal metastasis was extremely poor, but otherwise, the mortality rate was similar to that for the general population. Follow-up of AIs <4 cm with an initial nonfunctional profile and benign radiologic appearance appears unwarranted, but screening for congenital adrenal hyperplasia should be considered.

Common genetic variants of the human steroid 21-hydroxylase gene (CYP21A2) are related to differences in circulating hormone levels

Purpose

Systematic evaluation of the potential relationship between the common genetic variants of CYP21A2 and hormone levels.

Methods

The relationships of CYP21A2 intron 2 polymorphisms and haplotypes with diverse baseline and stimulated blood hormone levels were studied in 106 subjects with non-functioning adrenal incidentaloma (NFAI). The rationale for using NFAI subjects is dual: i) their baseline hormone profiles do not differ from those of healthy subjects and ii) hormone levels after stimulation tests are available.

Results

The carriers (N = 27) of a well-defined CYP21A2 haplotype cluster (c5) had significantly elevated levels of cortisol (p = 0.0110), and 17-hydroxyprogesterone (p = 0.0001) after ACTH stimulation, and 11-deoxycortisol after metyrapone administration (p = 0.0017), but the hormone values were in normal ranges. In addition, the carriers (N = 33) of the C allele of the rs6462 polymorphism had a higher baseline aldosterone level (p = 0.0006). The prevalence of these genetic variants of CYP21A2 did not differ between NFAI and healthy subjects.

Conclusions

The common CYP21A2 variants presumably exert the same effect on hormone levels in the healthy and disease-affected populations. Therefore, they may contribute to complex diseases such as some cardiovascular diseases, and may influence the genotype-phenotype correlation in patients with congenital adrenal hyperplasia (CAH) including the individual need for hormone substitution.

Non-functioning adrenal incidentalomas caused by 21-hydroxylase deficiency or carrier status?

Adrenal incidentalomas (AI) are an escalating clinical issue due to the increasing use of imaging techniques. Occasional patients with AIs have been reported who have subsequently been diagnosed with congenital adrenal hyperplasia (CAH) due to CYP21A2 mutations (21-hydroxylase deficiency) or carrier status. The objective of this investigation was to describe a larger cohort of patients with AI suspected to be caused by 21-hydroxylase deficiency or carrier status. All patients with AI and suspected CYP21A2 mutations during the last decade at a single center in Stockholm, Sweden, were included. Nine patients were identified (54 ± 19-year-old at presentation). Two-thirds were females and two-thirds were from Sweden, while one-third was from the Middle East. Almost all (8/9) had children, but two had experienced fertility problems. Four of six women had symptoms of hyperandrogenism, and three had previously been diagnosed with polycystic ovary syndrome. The majority (7/9) had multiple AIs. In two cases, the initial suspicion had been adrenal cortical cancer, but increased urinary pregnanetriol had lead to the diagnosis of CAH. Basal serum 17-hydroxyprogesterone was 10 (1.75-338) nmol/L. Seven was diagnosed with CAH (six non-classic, one simple virilizing). Two patients were considered to be carriers. However, in four patients, no CYP21A2 mutation was found and thus no confirmation of the diagnosis could be achieved. Patient presented with multiple AIs with hyperandrogenism or a Middle East origin screening for CAH or carrier status may be indicated.

Prostate gland development and adrenal tumor in a female with congenital adrenal hyperplasia: a case report and review from radiology perspective

We describe a case of a female with simple virilizing congenital adrenal hyperplasia (CAH) reared as a male diagnosed at the late age of 64. Computed Tomography (CT) demonstrated a large adrenal mass, bilateral diffuse adrenal enlargement, female pelvic organs as well as a clearly visualized prostate gland. This is to the best of our knowledge the first case of such a sizable prostate gland in a female CAH patient documented on CT. We review the literature regarding aspects where radiologists may encounter CAH and the finding of presence of a prostate gland in female CAH patients.

Inadequate testosterone suppression after medical and subsequent surgical castration in a patient with prostate cancer

Androgen deprivation is a cornerstone in prostate cancer management. We present a 69-year-old man, with a poorly differentiated prostate cancer with skeletal and lymph node metastases. After medical and subsequent surgical castration serum testosterone concentrations remained inappropriately high (4.9 and 4.5 nmol/L; castration range < 0.5). For cancer staging a CT was performed which showed bilateral adrenal enlargement. Endocrine workup revealed elevated levels of adrenal androgens and adrenal precursors. Mutation analysis confirmed a non-classical 21-hydroxylase deficiency, that is, a mild form of congenital adrenal hyperplasia (CAH). To suppress adrenocorticotrophic hormone and the excess adrenal androgen secretion, treatment with hydrocortisone and prednisolone was started with success. Inadequate testosterone suppression after castration due to previously undiagnosed CAH has not previously been reported. Considering the estimated prevalence of 1% in selected populations, non-classical CAH should be considered when testosterone is not adequately suppressed after castration in men with prostate cancer.

Clinical outcomes in the management of congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a group of disorders affecting adrenal steroid synthesis. The most common form, 21-hydroxylase deficiency, leads to decreased production of cortisol and aldosterone with increased androgen secretion. In classic CAH glucocorticoid treatment can be life-saving, and provides symptom control, but must be given in an unphysiological manner with the risk of negative long-term outcomes. A late diagnosis or a severe phenotype or genotype has also a negative impact. These factors can result in impaired quality of life (QoL), increased cardiometabolic risk, short stature, osteoporosis and fractures, benign tumors, decreased fertility, and vocal problems. The prognosis has improved during the last decades, thanks to better clinical management and nowadays the most affected patients seem to have a good QoL. Very few patients above the age of 60 years have, however, been studied. Classifying patients according to genotype may give additional useful clinical information. The introduction of neonatal CAH screening may enhance long-term results. Monitoring of different risk factors and negative consequences should be done regularly in an attempt to improve clinical outcomes further.

Adrenal myelolipomas in patients with congenital adrenal hyperplasia: review of the literature and a case report

OBJECTIVE

To review the association between congenital adrenal hyperplasia (CAH) and adrenal myelolipomas and report a case of bilateral, giant adrenal myelolipomas in a patient with untreated CAH due to 21-hydroxylase deficiency.

METHODS

We describe the patient's clinical presentation, imaging findings, and laboratory test results and review the relevant English-language literature concerning patients with both CAH and myelolipomas.

RESULTS

A 45-year-old man with untreated CAH due to 21-hydroxylase deficiency presented with increasing abdominal girth and abdominal pain. Computed tomography of the abdomen demonstrated very low-density adrenal masses (22 × 11 cm on the left side and 6 × 5.5-cm on the right side) consistent with adrenal myelolipomas. The left adrenal myelolipoma was resected (24.4 × 19.0 × 9.5 cm; 2557 g). The mass was composed of mature adipose tissue with areas of hematopoietic cells of myeloid, erythroid, and megakaryocytic cell lines. Islands of adrenal cortical cells were scattered between the adipose and hematopoietic tissue. Including the present case, we identified 31 patients with both CAH and myelolipomas who have been described in the English-language literature. The details of these cases were reviewed.

CONCLUSIONS

Persons with CAH may be at increased risk of developing adrenal myelolipomas, particularly if their CAH is poorly controlled. How and whether chronic exposure of the adrenal glands to high corticotropin levels increases the risk of developing myelolipomas remains a matter of speculation.

Phenotypic profiling of parents with cryptic nonclassic congenital adrenal hyperplasia: findings in 145 unrelated families

OBJECTIVE

To comprehensively phenotype parents identified with nonclassic congenital adrenal hyperplasia (NCCAH) by family genetic studies, termed here as cryptic NCCAH and to define the incidence of cryptic NCCAH in the parents of a large cohort of patients with 21-hydroxylase deficiency.

DESIGN

Genotyping was performed on 249 parents of 145 unrelated congenital adrenal hyperplasia (CAH) patients. Parents with two CYP21A2 mutations underwent extensive evaluation.

RESULTS

Of the 249 parents, ten (4%; seven females and three males) were identified as having cryptic NCCAH. The majority was of ethnicities previously reported to have a higher incidence of NCCAH. Cosyntropin stimulation performed in eight parents provided biochemical confirmation (17-hydroxyprogesterone range 56-364 nmol/l) and cortisol response was ≤500 nmol/l in three parents (38%). Of the seven women (27-54 years) with cryptic NCCAH, four had prior infertility, two reported irregular menses, two had treatment for hirsutism, one had androgenic alopecia. Men were asymptomatic. All cryptic NCCAH parents reported normal puberty and had normal height. Adrenal hypertrophy and a small adrenal myelolipoma were observed in two parents; testicular adrenal rest tissue was not found.

CONCLUSIONS

Parents diagnosed with NCCAH by genetic testing are mostly asymptomatic. Temporary female infertility and suboptimal cortisol response were commonly observed. Ongoing glucocorticoid therapy is not indicated in adults with CAH identified by family genotype studies unless symptomatic, but glucocorticoid stress coverage should be considered in select cases. Parents of a child with CAH have a 1:25 risk of having NCCAH; if the mother of a child with CAH has infertility, evaluation for NCCAH is indicated.

Pathogenesis of benign adrenocortical tumors

Most adrenocortical tumors (ACT) are benign unilateral adrenocortical adenomas, often discovered incidentally. Exceptionally, ACT are bilateral. However bilateral ACT have been very helpful to progress in the pathophysiology of ACT. Although most ACT are of sporadic origin, they may also be part of syndromic and/or hereditary disorders. The identification of the genetics of familial diseases associated with benign ACT has been helpful to define somatic alterations in sporadic ACT: for example, identification of PRKAR1A mutations in Carney complex or alterations of the Wnt/β-catenin pathway in Familial Adenomatous Polyposis Coli. Components of the cAMP signaling pathway-for example, adrenocorticotropic-hormone receptors and other membrane receptors, Gs protein, phosphodiesterases and protein kinase A-can be altered to various degrees in benign cortisol-secreting ACT. These progress have been important for the understanding of the pathogenesis of benign ACT, but already have profound implications for clinical management, for example in unraveling the genetic origin of disease in some patients with ACT. They also have therapeutic consequences, and should help to develop new therapeutic options.

Two adults with adrenal myelolipoma and 21-hydroxylase deficiency

We present incidentally discovered adrenal myelolipomas in two adult males with untreated congenital adrenal hyperplasia (CAH). The patients had simple virilizing form of CAH due to mutations in the CYP21 gene coding for 21-hydroxylase; one was heterozygous for the I172N mutation and the other compound heterozygous for the I172N and I2splice mutations. The masses were not removed since myelolipomas are considered benign tumors, and the tumor size did not increase during four- and nine-year observation periods. An adrenal myelolipoma is an important exception to the rule that large tumours should be removed. Untreated CAH with prolonged excessive ACTH stimulation might contribute to the growth of adrenal masses. CAH should be considered as a differential diagnosis of patients with adrenal masses or adrenal myelolipomas.

A male case of nonclassical 21-hydroxylase deficiency first manifested in his sixties with adrenocortical incidentaloma

Nonclassical form of 21-hydroxylase deficiency (NC 21OHD) as a frequent variant on the milder end of the disease spectrum has been widely acknowledged, but its potential contribution to adrenocortical tumorigenesis has not been fully elucidated. We report a 66-year old male case of bilateral adrenocortical incidentaloma, associated with partial 21OHD without any episodes of hypoadrenocorticism in his past history. He was demonstrated to be a compound heterozygous mutant of CYP21A2 gene (IVS2-13A/C>G/I172N). The two tumors in the left adrenal, which were interpreted as myelolipoma by imaging studies, were followed by sequential observation, whereas the contralateral large solid tumor associated with inhomogeneous radiological appearance was subsequently removed. The resected tumor was diagnosed an adrenocortical adenoma, which was devoid of P450c21 immunoreactivity. 21OHD is often associated with benign adrenocortical tumors, but bilateral adrenal tumors with heterogeneous components in both adrenals have not been reported to the best of our knowledge.

The role of 21-hydroxylase in the pathogenesis of adrenal masses: review of the literature and focus on our own experience

An exaggerated response of 17- hydroxyprogesterone (17-OHP) to exogenous ACTH stimulation has been found in 30 to 70% of patients with incidentally discovered adrenal tumors, supporting the concept that congenital 21- hydroxylase deficiency may be a predisposing factor for adrenocortical tumorigenesis. Decreased expression of 21-hydroxylase gene has been observed in sporadic non-functioning adrenocortical adenomas and adrenocortical carcinomas, in agreement with the reduced steroidogenic activity found in these types of tumors. Screening studies for the presence of mutations in CYP21A2 gene, encoding 21-hydroxylase, in patients with sporadic adrenocortical tumors yielded discordant results. Overall, a higher frequency of germline 21-hydroxylase mutation carriers has been found among patients with adrenal tumors, including incidentalomas, than in the general population. However, the presence of mutations did not correlate with endocrine test results and tumor mass features, suggesting that 21-hydroxylase deficiency does not represent a relevant mechanism in adrenal tumorigenesis. Mechanisms leading to reduced 21-hydroxylase expression and activity are still unknown.

Molecular genetics of adrenocortical tumours, from familial to sporadic diseases

Adrenal masses can be detected in up to 4% of the population, and are mostly of adrenocortical origin. Adrenocortical tumours (ACTs) may be responsible for excess steroid production and, in the case of adrenocortical cancers, for morbidity or mortality due to tumour growth. Our understanding of the pathogenesis of ACTs is more limited than that for other tumours. However, studies of the genetics of ACTs have led to major advances in this field in the last decade. The identification of germline molecular defects in the hereditary syndrome responsible for ACTs has facilitated progress. Indeed, similar molecular defects have since been identified as somatic alterations in sporadic tumours. The familial diseases concerned are Li-Fraumeni syndrome, which may be due to germline mutation of the tumour-suppressor gene TP53 and Beckwith-Wiedemann syndrome, which is caused by dys-regulation of the imprinted IGF-II locus at 11p15. ACTs also occur in type 1 multiple endocrine neoplasia (MEN 1), which is characterized by a germline mutation of the menin gene. Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD) has been observed in Carney complex patients presenting inactivating germline PRKAR1A mutations. Interestingly, allelic losses at 17p13 and 11p15 have been demonstrated in sporadic adrenocortical cancer and somatic PRKAR1A mutations have been found in secreting adrenocortical adenomas. More rarely, mutations in Gs protein (gsp) and the gene for ACTH receptor have been observed in ACTs. The genetics of another group of adrenal diseases that can lead to adrenal nodular hyperplasia -- congenital adrenal hyperplasia (CAH) and glucocorticoid-remediable aldosteronism (GRA) -- have also been studied extensively. This review summarizes recent advances in the genetics of ACTs, highlighting both improvements in our understanding of the pathophysiology and the diagnosis of these tumours.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) due to deficiency of 21-hydroxylase is a disorder of the adrenal cortex characterised by cortisol deficiency, with or without aldosterone deficiency, and androgen excess. Patients with the most severe form also have abnormalities of the adrenal medulla and epinephrine deficiency. The severe classic form occurs in one in 15,000 births worldwide, and the mild non-classic form is a common cause of hyperandrogenism. Neonatal screening for CAH and gene-specific prenatal diagnosis are now possible. Standard hormone replacement fails to achieve normal growth and development for many children with CAH, and adults can experience iatrogenic Cushing's syndrome, hyperandrogenism, infertility, or the development of the metabolic syndrome. This Seminar reviews the epidemiology, genetics, pathophysiology, diagnosis, and management of CAH, and provides an overview of clinical challenges and future therapies.

An 88-year-old woman diagnosed with adrenal tumor and congenital adrenal hyperplasia: connection or coincidence?

An 88-yr-old woman presented with a 3x4x5 cm adrenal incidentaloma. Apart from partial cortisol deficiency there were no clinical or laboratory signs of abnormal hormone production. Because of suspicion of carcinoma, a urinary steroid profile was carried out which indicated 21-hydroxylase deficiency with elevated pregnantriol. Biopsy of the tumor showed benign adenoma tissue. The genetic analysis showed two mutations in the CYP21-gene, V281L and 1172N consistent with mild non-classic congenital adrenal hyperplasia (CAH). The patient showed a general improvement with a low prednisolone dose. Previous reports have shown increased prevalence of CAH in patients with adrenal tumors although, to our knowledge, no one has reported the combination in a patient as old as in ours. Thus, clinical signs and symptoms of CAH should be looked for in patients with adrenal incidentalomas, even in the very old ones, and if suspicion further diagnostic work-up should be carried out to provide adequate treatment and follow-up.

Functional and nonfunctional adrenocortical tumors demonstrate a high responsiveness to low-dose adrenocorticotropin

Aldosterone-producing adenomas (APAs) demonstrate exquisite sensitivity to endogenous ACTH. We previously showed an ACTH receptor overexpression in APAs compared with the other adrenal tumors. To evaluate the meaning of such findings, we investigated the response of aldosterone, cortisol, and 17OH progesterone (17OHP) to 1 microg ACTH in 42 patients with adrenocortical tumors (23 NHAs, 9 APAs, and 10 CPAs) and 10 normal subjects (C). All 52 subjects were responsive to ACTH, and hormone peak levels were reached at 30 min. The aldosterone peak level was significantly higher in APAs [mean +/- SEM: 84.3 +/- 13.1 ng/dl (2335.1 +/- 362.9 pmol/liter)] than in other tumors and control (C). Cortisol peak levels was higher in CPAs [37.1 +/- 3.9 microg/dl (1023.9 +/- 107.6 nmol/liter)] than in NHAs (P < 0.01), in C (P < 0.01) and in APAs (P = n.s.). 17OHP peak levels were significantly higher in patients with adrenocortical tumors toward C. In summary: 1) low-dose ACTH induces an important stimulation in all tumors, suggesting preservation of high responsiveness to ACTH; 2) this is especially true for aldosterone in APA and could be of primary importance when performing diagnostic tests for hyperaldosteronism; and 3) 17OHP-hyperresponsiveness to low-dose ACTH is the most common alteration both in functional and nonfunctional tumors.