Immunoglobulins of patients with Cushing's syndrome due to pigmented adrenocortical micronodular dysplasia stimulate in vitro steroidogenesis

Effects of Chronic ACTH Excess on Human Adrenal Cortex

Chronic ACTH excess leads to chronic cortisol excess, without escape phenomenon, resulting in Cushing's syndrome. Excess adrenal androgens also occur: in females, they will overcompensate the gonadotrophic loss, inducing high testosterone; in males, they will not compensate it, inducing low testosterone. Chronic ACTH excess leads to chronic adrenal mineralocorticoid excess and low aldosterone levels: after an acute rise, aldosterone plasma levels resume low values after a few days when ACTH is prolonged. Two other mineralocorticoids in man, cortisol and 11 deoxycorticosterone (DOC), at the zona fasciculata, will not escape the long-term effect of chronic ACTH excess and their secretion rates will remain elevated in parallel. Over all, the concomitant rise in cortisol and 11 DOC will more than compensate the loss of aldosterone, and eventually create a state of chronic mineralocorticoid excess, best evidenced by the accompanying suppression of the renin plasma levels, a further contribution to the suppression of aldosterone secretion. Prolonged in vivo stimulation with ACTH leads to an increase in total adrenal protein and RNA synthesis. Cell proliferation is indicated by an increase in total DNA the resulting adrenocortical hyperplasia participates in the amplified response of the chronically stimulated gland, and the weight of each gland can be greatly increased. The growth-stimulatory effect of ACTH in vivo most likely proceeds through the activation of a local and complex network of autocrine growth factors and their own receptors; a number of compounds, including non-ACTH proopiomelanocortin peptides such as γ3-MSH, have been shown to exert some adrenocortical growth effect.

CT and MR Imaging of the Adrenal Glands in ACTH-independent Cushing Syndrome

Adrenocorticotropic hormone (ACTH)-independent hypercortisolism accounts for 15%-20% of cases of Cushing syndrome and always arises from primary adrenal disease. Computed tomographic (CT) and magnetic resonance (MR) imaging findings in 37 patients with primary adrenal Cushing syndrome were analyzed and correlated with pathologic findings. Hyperfunctioning adenomas (n = 24), together with functioning carcinomas (n = 10), accounted for 92% of cases. Adenomas had a significantly smaller mean size (3.5 vs 14.5 cm) and lower mean unenhanced CT attenuation value (11 vs 28 HU) than did carcinomas. The presence of necrosis, hemorrhage, and calcification favored a diagnosis of carcinoma. Six of 10 carcinoma patients had metastases at presentation. Two adenomas were seen within a myelolipoma, which was recognized at both CT and MR imaging due to its fat content, and two adenomas were of uncertain malignant potential. Bilateral disease--primary pigmented nodular adrenal dysplasia (PPNAD) (n = 2) and ACTH-independent macronodular adrenal hyperplasia (AIMAH) (n = 1)--had characteristic imaging features. In PPNAD, multiple tiny (2-5-mm) nodules were visible bilaterally, with no overall glandular enlargement and normal intervening adrenal tissue. In AIMAH, both glands were grossly enlarged and contained nodules up to 3 cm in diameter. Familiarity with the range of imaging appearances of the adrenal glands in primary adrenal Cushing syndrome may help establish the underlying diagnosis.

Autoimmune adrenal insufficiency and autoimmune polyendocrine syndromes: autoantibodies, autoantigens, and their applicability in diagnosis and disease prediction

Recent progress in the understanding of autoimmune adrenal disease, including a detailed analysis of a group of patients with Addison's disease (AD), has been reviewed. Criteria for defining an autoimmune disease and the main features of autoimmune AD (history, prevalence, etiology, histopathology, clinical and laboratory findings, cell-mediated andhumoral immunity, autoantigens and their autoepitopes, genetics, animal models, associated autoimmune diseases, pathogenesis, natural history, therapy) have been described. Furthermore, the autoimmune polyglandular syndromes (APS) associated with AD (revised classification, animal models, genetics, natural history) have been discussed. Of Italian patients with primary AD (n = 317), 83% had autoimmune AD. At the onset, all patients with autoimmune AD (100%) had detectable adrenal cortex and/or steroid 21-hydroxylase autoantibodies. In the course of natural history of autoimmune AD, the presence of adrenal cortex and/or steroid 21-hydroxylase autoantibodies identified patients at risk to develop AD. Different risks of progression to clinical AD were found in children and adults, and three stages of subclinical hypoadrenalism have been defined. Normal or atrophic adrenal glands have been demonstrated by imaging in patients with clinical or subclinical AD. Autoimmune AD presented in four forms: as APS type 1 (13% of the patients), APS type 2 (41%), APS type 4 (5%), and isolated AD (41%). There were differences in genetics, age at onset, prevalence of adrenal cortex/21-hydroxylase autoantibodies, and associated autoimmune diseases in these groups. "Incomplete" forms of APS have been identified demonstrating that APS are more prevalent than previously reported. A varied prevalence of hypergonadotropic hypogonadism in patients with AD and value of steroid-producing cells autoantibodies reactive with steroid 17alpha-hydroxylase or P450 side-chain cleavage enzyme as markers of this disease has been discussed. In addition, the prevalence, characteristic autoantigens, and autoantibodies of minor autoimmune diseases associated with AD have been described. Imaging of adrenal glands, genetic tests, and biochemical analysis have been shown to contribute to early and correct diagnosis of primary non-autoimmune AD in the cases of hypoadrenalism with undetectable adrenal autoantibodies. An original flow chart for the diagnosis of AD has been proposed.

Cushing's syndrome

During the past 30 years, there have been advances in understanding of the pathogenesis of Cushing's syndrome and in differential diagnosis of its various forms. Improved diagnostic tests and procedures have increased the ability to recognise even mild hypercortisolism and have provided the means to obtain an accurate diagnosis. Despite these advances, the occurrence of unusual clinical presentations and laboratory shortcomings may produce diagnostic problems and challenge clinical intuition. This article reviews recent pathogenic views, new tests, and new diagnostic problems in the evaluation of Cushing's syndrome. Atypical clinical presentations of hypercortisolism and some laboratory shortcomings that may confuse the diagnosis of Cushing's syndrome are also reported.

Paradoxical response to dexamethasone in the diagnosis of primary pigmented nodular adrenocortical disease

BACKGROUND

Primary pigmented nodular adrenocortical disease causes the Cushing syndrome in children and young adults and is most frequently associated with the Carney complex.

OBJECTIVE

To evaluate diagnostic tests for primary pigmented nodular adrenocortical disease.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care center.

PATIENTS

21 patients with primary pigmented nodular adrenocortical disease. The control groups consisted of 9 patients with macronodular adrenocortical disease and 15 patients with primary unilateral adrenocortical disease (single adenomas).

MEASUREMENTS

Clinical characteristics, radiologic imaging, and a 6-day Liddle test with determination of urinary free cortisol and 17-hydroxycorticosteroid excretion.

RESULTS

Adrenal imaging and other tests were of limited value for the diagnosis of primary pigmented nodular adrenocortical disease. The Liddle test, however, distinguished patients with this disorder from those with other primary adrenocortical lesions. An increase of 50% or more in urinary free cortisol levels on day 6 of the Liddle test identified 9 of 13 patients (69.2% [95% CI, 46.6% to 91.8%]) with primary pigmented nodular adrenocortical disease, excluded all patients with macronodular adrenocortical disease, and was present in only 3 of the 15 patients with single adrenocortical adenomas (20% [CI, 0% to 40.2%]). An increase in urinary free cortisol excretion of 100% or more on day 6 of the Liddle test identified only patients with primary pigmented nodular adrenocortical disease.

CONCLUSIONS

Patients with primary pigmented nodular adrenocortical disease responded to dexamethasone with a paradoxical increase in glucocorticoid excretion during the Liddle test. This feature distinguishes such patients from those who have the Cushing syndrome caused by other primary adrenal disorders and may lead to timely detection of the Carney complex (a potentially fatal disorder) in asymptomatic patients.

Myelolipoma: A New Adrenal Finding in Carney's Complex?

Pigmented nodular cortical hyperplasia. a rare cause of Cushing's syndrome, is characterized by resistance to inhibition with dexamethasone and normal sized adrenal glands with multiple, small, pigmented nodules. The disorder may be a component of a syndrome inherited as an autosomal dominant pattern that includes intra- and extracardiac myxomas, lentiginous lesions, blue nevi, other functional endocrire tumors, and perppheral nerve tumors (Carney's complex). We report a patient in whom bilateral myelolipomas were found, in addition to the usual features of this complex. A 29-yr old man was admitted to the hospital for Cushing's syndrome of probably more than 15 yr duration. Physical examination showed diffuse facial hyperchromatic macules. 02-05 cm, predominantly around the lips and on the palmar surfaces of the fingers. Results with dexamethasone suppression nocturnal testing (1 and 8 mg) were compatible with an adrenal adenoma. The computed tomography (CT) of the sella turcica was normal. Adrenal CT showed a tumor in the left gland with a double component one solid and another suggestive of fat, consistent with an angiomyelolipoma. Following 5 wk treatment with ketoconazole, 800 mg per day po, serum cortisol decreased to 5.9 Ag/dL. morning and evening, respectively. Bilateral adrenalectomy was performed. Pathologic examination revealed pigmented nodular cortical hyperplasia and a dominant myelolipoma in the left adrenal. A microscopic myelolipoma was identified in the right adrenal. An echocardiogram showed a mass on the posterior wall of the left ventricle which was a myxoma. Study of the patient's family disclosed two sisters with facial lentigines. Echocardiograms were performed on all available first degree relatives: all were normal. Nocturnal inhibition with dexamethasone revealed that one of the patient's sisters with lentigines also had hypercortisolism. Myelolipoma has been reported in association to Cushing syndrome in humans and experimentally after pituitary extracts in animals. The relationship between this finding and the Carney's complex remain elusive.

Cushing's syndrome

Cushing's syndrome is usually caused by the secretion of corticotropin or cortisol by a pituitary or adrenal tumor, respectively, or by ectopic secretion of corticotropin. It is possible to determine the specific abnormality in most patients, but it can sometimes be difficult to decide whether the patient has hypercortisolism and whether it is primary or due to major depressive disorder or to the stress of other diseases. Determining the cause of the hypercortisolism involves performing multiple tests in a logical sequence; the results should all be consistent with the same diagnosis. Treatment should aim to cure the hypercortisolism and to eliminate any tumor that threatens the patient's health, while minimizing the chance of an endocrine deficiency or long-term dependence on medications.

Cushing's syndrome due to primary pigmented nodular adrenocortical disease--a case report reviews of the literature

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of Cushing's syndrome in infants, children and young adults. It is characterized by non-adrenocorticotropic hormone-dependent hypersecretion of cortisol by multiple, pigmented nodules of hyperplastic adrenocortical cells. Biochemically, PPNAD is characterized by elevated levels of plasma and urinary cortisol that are not suppressed by high doses of dexamethasone (8mg/d for 2 days). Pathologically, the adrenal glands contain multiple dark brown or black nodules and the intervening cortical tissue is atrophic. Recognition of this diagnosis, although rare, is important, as bilateral adrenalectomy is the treatment of choice. We experienced a case of Cushing's syndrome due to primary pigmented nodular adrenocortical disease and report it with reviews of the literature.

Food-dependent Cushing's syndrome mediated by aberrant adrenal sensitivity to gastric inhibitory polypeptide

BACKGROUND

Some patients with Cushing's syndrome have nodular adrenal hyperplasia. In most the disease is corticotropin-dependent, but in others it is corticotropin-independent. The cause of the adrenal hyperplasia in the latter patients is not known.

METHODS

We studied a 49-year-old woman with Cushing's syndrome and nodular adrenal hyperplasia in whom food stimulated cortisol secretion. Plasma cortisol concentrations were measured in response to the ingestion of mixed meals, glucose, protein, and fat and after the administration of various gastrointestinal and other types of hormones. We also studied the ability of the long-acting somatostatin analogue octreotide to prevent the food-induced increase in plasma cortisol concentrations and to ameliorate the clinical manifestations of Cushing's syndrome in this patient.

RESULTS

The patient's fasting plasma cortisol concentrations were subnormal, ranging from 3.0 to 7.5 micrograms per deciliter (83 to 207 nmol per liter), and they increased to as high as 16.5 micrograms per deciliter (455 nmol per liter) after a mixed meal. Her urinary cortisol excretion ranged from 164 to 250 micrograms per day (453 to 690 nmol per day) and could not be suppressed by a large dose of dexamethasone. Plasma corticotropin concentrations were virtually undetectable at all times. The ingestion of glucose, protein, and fat increased plasma cortisol concentrations to 3.6, 2.2, and 4 times the base-line value, respectively; the meal-induced and glucose-induced increases were inhibited by octreotide. The infusion of gastric inhibitory polypeptide (GIP) increased the patient's plasma cortisol concentration to 3.7 times the base-line value, but had no effect in normal subjects. The patient's fasting plasma GIP concentrations were normal both before and after a meal, and there was a close correlation between her plasma cortisol and GIP concentrations. Treatment with octreotide decreased urinary cortisol excretion and ameliorated the clinical manifestations of Cushing's syndrome.

CONCLUSIONS

The development of aberrant adrenal sensitivity to GIP can result in food-dependent adrenal hyperplasia and therefore in Cushing's syndrome.

Macronodular adrenal hyperplasia causing Cushing's syndrome: report of two cases and an overview

Of the various entities producing adrenal hyperfunction, nodular adrenal hyperplasia is rarely described, however, recent reports have established it as a distinct cause of Cushing's syndrome. Although the etiology of this disease remains uncertain, two distinct forms are recognised, namely: macronodular hyperplasia and micronodular dysplasia. Establishing the diagnosis preoperatively is difficult but essential to ensure the correct treatment is performed. Two cases of macronodular hyperplasia are reported herein followed by a review of the available literature on this subject.

The Cushing syndromes

The 10 years since this journal's last review of CS have seen extraordinary advances in our understanding of many aspects of its causes, diagnosis, and treatment. The spectrum of what are now called the Cushing syndromes has expanded considerably to include CD, multiple sources of ectopic ACTH secretion, and an apparent autoimmune cause. Improved assays of ACTH and the availability of CRF have provided new insight into the physiology and pathophysiology of the HPA axis and new tools for diagnosis of CS, especially in combination with selective catheterization and sampling. New imaging technology has improved our visualization of pituitary adenomas and has provided powerful methods for identifying tumors ectopically secreting ACTH and primary adrenal tumors. Finally, the refinement of transsphenoidal surgery and its success in treating CD have provided a safe and effective therapy for this disease. For those occasional patients who require medical therapy, drugs are available that decrease steroid biosynthesis. We now have a much better understanding of a fascinating disease process and are able to diagnose and treat it more correctly. One is impatient to see which new pieces of this puzzle will fall into place over the next ten years.

Receptor autoimmunity in endocrine disorders

The discovery in 1956 of the long-acting thyroid stimulator of Graves' disease, now known as thyroid-stimulating antibodies, was seminal. A new mechanism for disease was revealed that appears applicable to virtually all endocrine systems, involving the growth as well as the function of endocrine cells. An endocrine gland may fail through at least three autoimmune mechanisms: destruction, atrophy, and inhibition of function. Destruction is probably irreversible but is not usually distinguishable clinically from receptor blockade causing atrophy or from metabolic unresponsiveness. The contribution made by receptor autoimmunity to endocrine diseases other than thyroid disease is at present unclear, but with immunologic manipulation it is potentially reversible, improving the replicative capacity of the gland, its metabolic responsiveness, or both.

Multiple endocrine neoplasia: how many syndromes?

The phrase multiple endocrine neoplasia (MEN) generally denotes an association of tumors so specific as to constitute a syndrome. Three well-recognized such syndromes exist. All are autosomal dominant traits and all have been tentatively mapped to specific chromosomes. Other purported endocrine tumor syndromes have been suggested either as new entities or as subtypes of the existing MEN syndromes. The evidence in favor of these contentions is examined critically. Only one "new" association, that of pheochromocytomas and islet cell tumors, seems reasonable, and even in this setting, some relatives have had manifestations of von Hippel-Lindau syndrome. There is no compelling reason why such conditions as von Hippel-Lindau syndrome, peripheral neurofibromatosis, McCune-Albright syndrome, and others should be reclassified as MEN syndromes, although awareness of their collective endocrine abnormalities is clinically important.

Sexual precocity induced by ovarian follicular cysts. Is autoimmunity involved?

A 2-year-old girl presented with gonadotrophin-independent precocious puberty due to ovarian follicles. Central precocious puberty was excluded by several GnRH-tests and overnight LH sampling. There were no signs of McCune-Albright syndrome. An ovarian tumour was excluded by laparotomy and biopsies. Abdominal sonography demonstrated follicles occurring mostly in the left, sometimes in the right, ovary. Immunoglobulin G (IgG) purified from the patient's serum was capable of stimulating DNA synthesis in granulosa cells of rat ovarian segments kept in organ culture. Since FSH had a similar in-vitro action it is hypothesized that this patient's IgG mimics the action of FSH.

Primary adrenocortical micronodular dysplasia: enzyme histochemical and ultrastructural studies of two cases with a review of the literature

The adrenal glands from two patients with primary adrenocortical micronodular dysplasia (PAMD) were studied (no. 1, a 23-year-old man with cardiac myxomas and sarcoidosis; no. 2, a 16-year-old girl). The PAMD cells showed intense activity of 3 beta-hydroxysteroid dehydrogenase (3 beta DH), succinate DH, glucose-6-phosphate DH, alkaline phosphatase (AlPase), and other DHs and lysosomal hydrolases, giving a characteristic staining pattern. The staining patterns correlated well with ultrastructural findings. The larger adrenals (no. 1: 16.6 g) were associated with larger black nodules and internodular cortex (INC) with fairly well-retained enzyme activities, and contained cell clusters and single cells with intense AlPase activity with the appearance of PAMD nodules in the buds. The smaller adrenals (no. 2: 5.4 g) were associated with smaller black/yellow nodules, and had INC with weaker enzyme activity. Analysis of descriptions of INC in 25 previously reported cases revealed that the larger adrenals (more than 10 g) had less atrophic INC than the smaller ones. The characteristic enzyme pattern in PAMD cells explains the paradox that PAMD adrenals smaller than normal can cause Cushing's syndrome, and may be useful for investigating neoplastic and non-neoplastic counterparts in other adrenal lesions. The relationship between PAMD cells and INC is not simply one of autonomy versus atrophy, and both cell types may be stimulated by a certain common trophic factor. Thus, PAMD belongs to the category of hyperplasia.

Primary pigmented micronodular disease of the adrenals

Primary pigmented micronodular disease is a peculiar form of ACTH-independent Cushing's syndrome characterized by the familial occurrence, the frequent association with malformations and the pathological adrenocortical picture consisting in micronodules with cellular deposition of lipofuscinic pigment. We describe here a case occurring in a 14-year-old girl.

Receptors in disease: an overview

Hormones and certain other signal molecules bind to plasma membrane or intracellular receptors producing signals that initiate their physiological effects. Recent understanding of receptors has resulted in recognition of several categories of receptor-related abnormalities. (a) Congenital receptor abnormalities such as receptor deficiency syndrome. LDL receptor defect in familial hypercholesteremia and primary androgen resistance are examples. (b) Postreceptor coupling abnormalities such as pseudohypoparathyroidism type Ia where there are reduced levels of guanine nucleotide receptor cyclase coupling protein. (c) Acquired receptor abnormalities, such as presence of circulating antireceptor antibodies. Such antibodies have been implicated in the pathophysiology of many diseases including Graves' disease and myasthenia gravis.

Autoimmune involvement in Cushing syndrome due to primary adrenocortical nodular dysplasia

Cushing syndrome due to primary adrenocortical nodular dysplasia was diagnosed in two patients, aged 3 years 9 months and 9.5 years. Subsequently, adrenalectomy was performed and followed by steroid replacement. In both cases, the adrenals were normal or only slightly enlarged and showed adrenocortical nodular dysplasia histologically. Small lymphocytic infiltrates consisting of T-cells and class II MHC positive macrophages were present in adrenal specimens of both the patients. Samples of protein A sepharose purified serum immunoglobulins from both children stimulated adrenocortical DNA synthesis and cortisol production in cultured guinea-pig adrenal segments in vitro in a dose dependent fashion. Adrenal stimulating immunoglobulins were also demonstrated in serum specimens of both patients' mothers. However, none of them had overt signs of adrenal disease. Our data support the view that autoimmune mechanisms may be involved in primary adrenocortical nodular dysplasia.

Familial Cushing's syndrome due to nodular adrenocortical dysplasia is an inherited disease of immunological origin

Circulating immunoglobulins may be involved in the pathogenesis of familial Cushing's syndrome due to nodular adrenocortical dysplasia. The disease may also be part of a complex including cutaneous and cardiac myxomas, spotty pigmentation of the skin, and other signs of endocrine overactivity. In the present study of two sisters treated by complete adrenalectomy for Cushing's syndrome due to nodular adrenocortical dysplasia, and of their first-degree relatives, no evidence of associated disorders was present. However, the serum of both girls and of their mother contained immunoglobulins capable of stimulating adrenal DNA synthesis and cortisol production in vitro. The study supports the theory that familial Cushing's syndrome due to adrenocortical dysplasia is an inherited disease of immunological origin.

Primary adrenal causes of Cushing's syndrome. Diagnosis and surgical management

Cushing's syndrome is rare with only 20% of patients having a primary adrenal cause of hypercortisolism. We have developed a strategy to evaluate patients with suspected Cushing's syndrome and to localize the pathologic condition responsible for the hypercortisolism. This report reviews the last 11 consecutive patients who had a primary adrenal cause of hypercortisolism. Each patient had elevated 24-hour urine free cortisol and 17-hydroxycorticosteroid excretion consistent with hypercortisolism. All but one patient had undetectable plasma ACTH levels. No patient suppressed urinary steroid levels with high-dose dexamethasone and only one patient increased plasma ACTH or cortisol levels with oCRH, findings that were consistent with a pituitary-independent form of hypercortisolism. No patient had a pituitary tumor detected by computed tomography or magnetic resonance imaging, and eight patients had adrenal tumors accurately imaged. MRI of the adrenal glands correctly diagnosed adenoma in 5 of 6 patients with adenomas, carcinoma in 1 patient, and ACTH-producing pheochromocytoma in 1 patient. One tumor classified as carcinoma by MRI appeared on pathologic examination to be an adenoma. Three patients underwent petrosal sinus sampling for measurement of ACTH before and after oCRH administration, and each had petrosal sinus ACTH levels equal to peripheral levels, consistent with a primary adrenal cause of hypercortisolism. Two of these patients had typical bilateral pigmented micronodular adrenocortical disease and the third patient had macronodular adrenocortical hyperplasia. Each of the 11 patients was cured of hypercortisolism by unilateral or bilateral adrenalectomy and no patient has developed recurrent disease during the 7 to 29 month follow-up period. New modalities including the ovine CRH test, MRI, and petrosal sinus sampling have improved the evaluation of certain patients with Cushing's syndrome.