Work-up and management of paediatric Cushing's syndrome

Neurosurgical aspects and clinical outcomes on the treatment of Cushing disease in pediatric patients: Case series and literature review

Background

Cushing disease (CD) is a state of hypercortisolism caused by an adrenocorticotropic hormone-(ACTH) producing pituitary adenoma which rarely occurs in pediatric patients. The outstanding features are weight gain and growth retardation. However, the insidious onset and rarity of the disease in children and adolescents often result in delayed diagnosis.

Case Description

We present five patients <14 years of age who underwent neurosurgical treatment for CD at the Department of Neurosurgery of a public referral hospital in Lima, Peru. Age at diagnosis ranged from 5.5 to 12.5 years with a history of disease from 9 months to 3.5 years of moderate to severe stunting and obesity, among other features of Cushing syndrome (CS). Although biochemical tests and cerebral imaging were crucial for the diagnosis, confirmation was made by bilateral petrosal sinuous sampling. Regarding treatment, three patients underwent transcranial surgery, one patient underwent endoscopic transsphenoidal surgery, and one patient underwent microscopic transsphenoidal surgery. None of the patients underwent radiotherapy or pharmacological treatment. Only one patient had a recurrence and achieved remission until an endoscopic transsphenoidal approach was performed. Short- and long-term endocrinologic follow-up is also described in detail.

Conclusion

CD is a heterogeneous disorder that requires multidisciplinary diagnosis and management. Transsphenoidal selective adenomectomy is the optimal treatment because of its higher remission rates. However, technical and anatomic aspects should be considered in pediatric patients.

Approach to Diagnosing a Pediatric Patient With Severe Insulin Resistance in Low- or Middle-income Countries

Diabetes mellitus (DM) in children is most often caused by impaired insulin secretion (type 1 DM). In some children, the underlying mechanism for DM is increased insulin resistance, which can have different underlying causes. While the majority of these children require insulin dosages less than 2.0 U/kg/day to achieve normoglycemia, higher insulin requirements indicate severe insulin resistance. Considering the therapeutic challenges in patients with severe insulin resistance, early diagnosis of the underlying cause is essential in order to consider targeted therapies and to prevent diabetic complications. Although rare, several disorders can attribute to severe insulin resistance in pediatric patients. Most of these disorders are diagnosed through advanced diagnostic tests, which are not commonly available in low- or middle-income countries. Based on a case of DM with severe insulin resistance in a Surinamese adolescent who was later confirmed to have autosomal recessive congenital generalized lipodystrophy, type 1 (Berardinelli-Seip syndrome), we provide a systematic approach to the differential diagnosis and work-up. We show that a thorough review of medical history and physical examination generally provide sufficient information to diagnose a child with insulin-resistant DM correctly, and, therefore, our approach is especially applicable to low- or middle-income countries.

An Optimized Pathway for the Differential Diagnosis of ACTH-Dependent Cushing's Syndrome Based on Low-Dose Dexamethasone Suppression Test

CONTEXT

Traditionally, low-dose dexamethasone suppression test (LDDST) was used to confirm the diagnosis of Cushing's syndrome (CS), and high-dose dexamethasone suppression test (HDDST) was used to differentiate Cushing's disease (CD) and ectopic adrenocorticotropin (ACTH) syndrome (EAS), but some studies suggested that HDDST might be replaced by LDDST. For the differential diagnosis of CS, dexamethasone suppression test was usually combined with other tests such as bilateral petrosal sinus sampling (BIPSS) and pituitary magnetic resonance imaging, but the optimal pathway to incorporate these tests is still controversial.

OBJECTIVES

To develop an optimized pathway for the differential diagnosis of CD and EAS based on LDDST.

DESIGN AND SETTING

Single-center retrospective study (2011-2019).

PATIENTS

Two hundred sixty-nine CD and 29 EAS patients with pathological diagnosis who underwent consecutive low- and high-dose DST.

RESULTS

For the differential diagnosis of CD and EAS, the area under curve (AUC) of LDDST using urine free cortisol (0.881) was higher than that using serum cortisol (0.685) (p < 0.001) in head-to-head comparison among a subgroup of 108 CD and 10 EAS. The AUC of LDDST (0.883) was higher than that of HDDST (0.834) among all the included patients. With the cutoff of <26%, the sensitivity and specificity of LDDST were 39.4% and 100%. We designed a new pathway in which BIPSS was only reserved for those patients with unsuppressed LDDST and adenoma <6mm, yielding an overall sensitivity of 97.7% and specificity of 86.7%.

CONCLUSION

LDDST had similar value to HDDST in differentiating CD and EAS using the specific cutoff point. The pathway that combined LDDST and BIPSS could differentiate CD and EAS accurately.

Bronchial Carcinoid Tumour as a Rare Cause of Cushing’s Syndrome in Children: A Case Report and Review of Literature

Cushing’s syndrome (CS) is rare in childhood and adolescence. The most common paediatric cause of CS is exogenous administration of glucocorticoids; either topical, inhaled or oral corticosteroids. Endogenous causes can be classified into adrenocorticotropic hormone (ACTH) independent and ACTH dependent causes. Herein, we report our experience of managing a 12 year old girl who presented with features of CS and was found to have an ectopic, ACTH-secreting bronchial carcinoid tumour, which was resected surgically. Our patient was managed successfully by multidisciplinary approach and has recovered from hypertension and Cushing’s habitus. The English language literature was searched from 2019 back, using PubMed, Google and Google Scholar. Keywords used for the search were; “Ectopic ACTH syndrome (EAS) in children”, “bronchial carcinoid in children” and “Cushing’s Syndrome in children”. Children with bronchial carcinoid tumours causing EAS were identified. Case variables such as age, sex, type of carcinoid, investigations, surgery, recurrences and outcome were reviewed. Fourteen cases of paediatric bronchial carcinoid producing ACTH were found with a mean age of 15.8 years and female preponderance. Most of the patients had a right lung lesion and histological appearance was typical of carcinoid tumour. Bronchial carcinoid is extremely rare in children and only 4% are associated with CS. The postoperative treatment of CS is challenging with a high prevalence of hypertension, increased body mass index and visceral fat mass, impaired cognitive function and decreased quality of life. A careful follow up is indispensable for monitoring recurrence of carcinoid and complete remission of CS.

Cushing’s Disease due to ACTH Secreting Pituitary Microadenoma: A Single Institutional Experience of Four Cases

ACTH secreting pituitary adenomas are rare occurrences in autoptical, surgical and neuroradiological series. We herewith describe a series of four patients of Cushing’s disease due to ACTH secreting pituitary microadenoma. All patients presented with signs and symptoms of hypercortisolism. Hormonal testing and bilateral inferior petrosal sinus sampling were indicative of pituitary-dependent Cushing’s syndrome. Dynamic sellar MRI was suggestive of asymmetric pituitary, with suspect pituitary microadenoma in all cases. Three patients were operated for endoscopic endonasal transsphenoidal surgery, while one patient refused surgery and was managed with ketoconazole. During postoperative period, remission of hypercortisolism was ensured in two patients, while one patient continued to have raised levels of cortisol. One patient with raised levels of cortisol during postoperative period was prescribed Ketoconazole for 6 months. Histopathology confirmed the presence of pituitary adenoma. Adenoma displayed ACTH immunoreactivity. Our cases indicate that ACTH secreting pituitary microadenoma may occur in patients with Cushing’s disease. Careful radiological, surgical and pathological examination is necessary to recognize this condition and avoid surgical failure.

PRIMARY PIGMENTED NODULAR ADRENOCORTICAL DISEASE (PPNAD) PRESENTING AS CUSHING SYNDROME IN A CHILD AND REVIEW OF LITERATURE

Cushing syndrome in the paediatric age group is very difficult to diagnose due to atypical presenting features in children. Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent Cushing syndrome in children and it has characteristic gross and microscopic pathologic features. We report a case of PPNAD in a 16-year-old boy who was evaluated in our hospital with chief complaints of poor height velocity and rapid weight gain for 2-3 years before presentation. Proper evaluation showed ACTH-independent Cushing syndrome with normal imaging. Total bilateral adrenalectomy was performed followed by hormones replacement. 6 months after surgery, significant acceleration of height velocity was noticed. Patient also lost body weight and developed secondary sexual characteristics.

Detection of new potentially pathogenic mutations in two patients with primary pigmented nodular adrenocortical disease (PPNAD) - case reports with literature review

INTRODUCTION

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare form of ACTH-independent Cushing's syndrome (CS). Half of patients with PPNAD are sporadic cases and the other half familial.

MATERIAL AND METHODS

We present two patients with PPNAD confirmed by genetic analysis.

RESULTS

In both patients there were no abnormal findings on diagnostic imaging of both adrenals and heart. Patients underwent bilateral two-stage adrenalectomy. Histopathological examination confirmed PPNAD. Genetic testing showed the following mutations in the PRKAR1A gene coding for the regulatory subunit type 1A of the protein kinase A enzyme: c.125dupG (patient 1) and c.15dupT (patient 2). Both these defects lead to inactivation of the PRKAR1A protein and are consequently causative of PPNAD in these patients.

CONCLUSIONS

The novel mutations presented in this article are considered to be pathogenic for PPNAD.

Management of Cushing syndrome in children and adolescents: experience of a single tertiary centre

The diagnosis and management of paediatric Cushing syndrome (CS) is highly challenging. This study aims to characterise its presentation, diagnosis, management and outcome by a retrospective case review of 30 patients (14 females) followed at a single tertiary paediatric endocrinology centre over a 30-year period. At presentation, median age was 8.9 years (0.2-15.5) and the commonest manifestations were weight gain (23/30), hirsutism (17/30), acne (15/30) and hypertension (15/30). Growth retardation was present in 11/30. Median body mass index (BMI) was +2.1 standard deviation score (SDS) (-6.5 to +4.6). Urinary free cortisol (UFC) was abnormal in 17/18 (94 %), midnight cortisol in 27/27 (100 %) and low-dose dexamethasone suppression (LDDS) test in 20/20 (100 %). High-dose dexamethasone suppression (HDDS) test was abnormal in 6/6 (100 %) of adrenal tumours, 1/10 (10 %) of Cushing disease (CD) and 1/2 (50 %) of ectopic tumours. Bilateral inferior petrosal sinus sampling (IPSS) identified five CD cases and one ectopic tumour. All patients underwent surgery and subsequently required cortisol replacement. Final diagnoses were 16 CD, 11 adrenal disease, 2 ectopic ACTH-secreting lesions and 1 case of unidentified aetiology. One year post-diagnosis, median BMI was 0.5 SDS (-2.5 to +3.7), hypertension was present in 4/14 (28 %), and 43 % (12/30) of individuals were off hydrocortisone.

CONCLUSION

The prevalence of the clinical manifestations differs from that reported in other series. Screening tests were highly sensitive, with UFC, midnight cortisol and LDDS performing well. One year post-treatment, BMI and BP normalised in the majority of patients and almost half of them were able to discontinue replacement hydrocortisone.

WHAT IS KNOWN

•Cushing syndrome is an extremely rare entity in the paediatric and adolescent age groups, so not many cohort studies have been published in this population. •Several tests can be employed to firstly diagnose hypercortisolaemia and secondly identify the source of origin of it. The efficacy and safety of these tests in children is still uncertain. What is New: •This study includes cases due to the different aetiologies of endogenous hypercortisolaemia (pituitary, adrenal and ectopic hypercortisolaemia) allowing us to compare the differences in presentation, diagnosis, management and long-term outcome between the groups. •There is a difference in the prevalence of Cushing syndrome symptoms and in the performance of the tests in our cohort compared to previously published studies in the literature.

A patient with Cushing disease lateralizing a pituitary adenoma by inferior petrosal sinus sampling using desmopressin: a case report

A 14-year-old girl was referred for evaluation of the etiology of Cushing syndrome. During the previous 2 years, she had experienced weight gain, secondary amenorrhea, growth retardation, and back pain. Random serum cortisol level, 24-hour urinary free cortisol excretion, and overnight and low-dose dexamethasone suppression tests suggested Cushing syndrome. Midnight adrenocorticotropic hormone (ACTH) level and high-dose dexamethasone suppression test confirmed Cushing disease. Pituitary magnetic resonance imaging was suspicious for microadenoma. To eliminate ectopic ACTH syndrome, and lateralize the pituitary tumor, inferior petrosal sinus sampling (IPSS) was performed by desmopressin use to stimulate ACTH. Finally, the patient was diagnosed with Cushing disease due to ACTH-secreting pituitary microadenoma, lateralized to the left side; subsequently underwent transsphenoidal surgery. Here we report a case of a 14-year-old girl diagnosed with Cushing disease with a pituitary tumor lateralized by IPSS using desmopressin, which is very rare in pediatric Cushing disease.

Death in pediatric Cushing syndrome is uncommon but still occurs

Cushing syndrome (CS) in children is rare. Delayed diagnosis and treatment of CS may be associated with increased morbidity and, unfortunately, mortality. We performed a retrospective review of all patients with CS under the age of 18 years referred to the National Institutes of Health (NIH) from 1998 to 2013 in order to describe deceased patients among cases of pediatric CS referred to the National Institutes of Health (NIH). The deaths of four children (three females and one male), aged 7.5-15.5 years (mean age 11.2 years) with length of disease 2-4 years, were recorded among 160 (2.5 %) children seen at or referred to the NIH over the last 15 years. All died at different institutions, prior to coming to the NIH (two) or after leaving NIH (two). Presenting symptoms included increasing weight and decreasing height gain, facial plethora, dorsocervical fat pad (webbed neck), striae, headache, vision disturbances, and depression and other mood or behavior changes; there were no differences between how these patients presented and the others in our cohort. The causes of CS in the deceased patients were also not different, in fact, they spanned the entire spectrum of CS: pituitary disease (one), ectopic corticotropin production (one), and primary adrenal hyperplasia (one). In one patient, the cause of CS could not be verified. Three died of sepsis and one due to residual disease and complications of the primary tumor.

CONCLUSIONS

Despite the advances in early diagnosis and treatment of pediatric CS, a 2.5 % mortality rate was identified in a large cohort of patients with this condition referred to an experienced, tertiary care referral center (although these deaths occurred elsewhere). Pediatricians need to recognize the possibility of death, primarily due to sepsis, in a patient with pediatric CS and treat accordingly.

Poor head growth as a presenting sign of a cortisol-secreting adrenal adenoma in a 2-year-old boy

Typical signs of glucocorticoid excess in children are weight gain and poor linear growth. We describe a 2-year-old boy with a cortisol-secreting adenoma who presented with a dramatic decline in head growth. This case underscores concern of adverse effects of excess glucocorticoid on brain growth in very young children.

Gallium-68 DOTA-TATE Positron Emission Tomography/Computed Tomography: Scintigraphic Changes of Adrenal Glands Following Management of Ectopic Cushing's Syndrome by Steroidogenesis Inhibitors

In the era of emerging functional imaging techniques, an understanding of the effects of hormonal therapies on the scintigraphic appearance of endocrine organs is desirable to minimize the erroneous scan interpretation. The mechanisms by which changes in the scintigraphic appearance of endocrine organs occur however sometimes remain ambiguous. This case demonstrates the gallium-68 (Ga-68) DOTA-TATE positron emission tomography/computed tomography (CT) appearance of adrenal glands following management with steroidogenesis inhibitors. The potential mechanisms underlying this change are discussed. A 17-year-old boy with adrenocorticotropic hormone (ACTH) dependent Cushing's syndrome secondary to ectopic ACTH secretion underwent pre- and post-metyrapone and dexamethasone treatment Ga-68 DOTA-TATE scans 4 months apart. Pretreatment, both adrenals demonstrated normal symmetrical prominent Ga-68 DOTA-TATE uptake and normal CT appearance. The posttherapy scan revealed marked symmetrical suppression of Ga-68 DOTA-TATE uptake, but with bilateral adrenal hypertrophy on CT.

Approach to the Cushing's disease patient with persistent/recurrent hypercortisolism after pituitary surgery

Although it is the ideal treatment, pituitary surgery is not always successful, and success is not always lasting. Close surveillance, clinical and biological, will detect immediate failure or late recurrence. The reason must be thoroughly explored with the somewhat dogmatic rule that the patient should be offered the best surgery in expert hands, and a repeat surgical attempt must be systematically discussed. When repeat pituitary surgery is not indicated or has failed, then comes the difficult task to choose between a number of options directed toward different targets: directly suppress tumor ACTH by pituitary radiotherapy (conventional or stereotaxic) or with medications (somatostatin analog such as pasireotide, or dopaminergic drug such as cabergoline), directly suppress adrenocortical activity with medications (inhibitors of adrenal steroidogenesis such as ketoconazole or metyrapone, or the adrenolytic Lysodren), or by surgery (bilateral adrenalectomy), and finally oppose peripheral cortisol action with the antiglucocorticoid mifepristone. No single option is ideal, able to provide at the same time a high success rate and a rapid onset of action, to restore a normal pituitary adrenal axis, and to have good tolerability. Close follow-up and thorough evaluation of the cortisolic status will eventually dictate a switch in treatment options and/or combination strategies over time. The tumor status and its possible oncogenic threat, the severity of the hypercortisolism, and the patient perspectives (wish of fertility) are among the major parameters that can help a multidisciplinary approach toward the best option.

Combined treatment with GH and anastrozole in a pubertal boy with Cushing's disease and postsurgical GH deficiency

Growth failure is a characteristic manifestation of pediatric Cushing's disease. Catch-up growth is usually incomplete after cure of the disease, and final height is often compromised. Possible mechanisms for this phenomenon include postoperative persistence of GH hyposecretion and absence of retardation of bone maturation in spite of GH deficiency. This report describes the outcome in the case of a boy with Cushing's disease for whom GH replacement therapy was combined with anastrozole, an aromatase inhibitor, in order to delay skeletal maturation and extend the available time for linear growth. The case of a 14 years 4-months-old pubertal male (Tanner stage III) with GH deficiency after successful surgical treatment of Cushing's disease is presented. His height was 147.2 cm (-2.34 SDS), and his midparental target height 171.2 cm (-0.95 SDS). Bone age was 13.5 years and predicted adult height 163.2 cm (-2.2 SDS). Combined treatment was administered for 2.5 years. GH was maintained up to age 18 years. Anastrozole induced a substantial deceleration of bone age. Near-final height at 18 years was 169.5 cm (-1.07 SDS). Puberty progressed normally. Compared with population reference data, bone mineral density before GH plus anastrozole treatment was -4.07 SDS in the lumbar spine and -1.85 SDS in the femoral neck. These measures increased to -1.95 and -0.89 SDSs respectively, at 18 years, when GH was discontinued. Combined treatment with GH and aromatase inhibitors could be a therapeutic alternative to improve the stature of pubertal boys with Cushing's disease and postsurgical GH deficiency.

Recovery of the hypothalamic-pituitary-adrenal axis in children and adolescents after surgical cure of Cushing's disease

CONTEXT

Recovery of the hypothalamic-pituitary-adrenal axis (HPAA) after transsphenoidal surgery (TSS) for Cushing's disease (CD) in children has not been adequately studied.

OBJECTIVE

Our objective was to assess time to recovery of the HPAA after TSS in children with CD.

DESIGN AND SETTING

This was a case series at the National Institutes of Health Clinical Center.

PATIENTS

Fifty-seven patients with CD (6-18 yr, mean 13.0 ± 3.1 yr) given a standard regimen of glucocorticoid tapering after TSS were studied out of a total of 73 recruited.

INTERVENTIONS

ACTH (250 μg) stimulation tests were administered at approximately 6-month intervals for up to 36 months. Age, sex, pubertal status, body mass index, length of disease, midnight cortisol, and urinary free cortisol at diagnosis were analyzed for effects on recovery.

MAIN OUTCOME MEASURE

The main outcome measure was complete recovery of the HPAA as defined by a cortisol level of at least 18 μg/dl in response to 250 μg ACTH.

RESULTS

Full recovery was reached by 43 (75.4%) of 57 patients, with 29 of the 43 (67.4%) and 41 of the 43 (95.3%) recovering by 12 and 18 months, respectively. The overall mean time to recovery was 12.6 ± 3.3 months. Kaplan-Meier survivor function estimated a 50% chance of recovering by 12 months after TSS and 75% chance of recovering within 14 months. By receiver operating characteristic curve assessment, the cutoff of at least 10-11 μg/dl of cortisol as the peak of ACTH stimulation testing at 6 months after TSS yielded the highest sensitivity (70-80%) and specificity (64-73%) to predict full recovery of the HPAA at 12 months. Two of the four patients that recovered fully within 6 months had recurrent CD.

CONCLUSIONS

Although this is not a randomized study, we present our standardized tapering regimen for glucocorticoid replacement after TSS that led to recovery of the HPAA in most patients within the first postoperative year. Multiple factors may affect this process, but an early recovery may indicate disease recurrence.

Late gestational maternal serum cortisol is inversely associated with fetal brain growth

To analyze the association between fetal brain growth and late gestational blood serum cortisol in normal pregnancy.Blood total cortisol was quantified at delivery in 432 Chinese mother/child pairs. Key inclusion criteria of the cohort were: no structural anomalies of the newborn, singleton pregnancy, no alcohol abuse, no drug abuse or history of smoking no hypertensive disorders and no impairment of glucose tolerance and no use of steroid medication during pregnancy. Differential ultrasound examination of the fetal body was done in early (gestational day 89.95 ± 7.31), middle (gestational day 160.17 ± 16.12) and late pregnancy (gestational day 268.89 ± 12.42). Newborn's cortisol was not correlated with any of the ultrasound measurements during pregnancy nor with birth weight. Multivariable regression analysis, considering timing of the ultrasound examination, the child's sex, maternal BMI, maternal age, maternal body weight at delivery, the timing of cortisol measurement and maternal uterine contraction states, revealed that maternal serum total cortisol was significantly negative correlated with ultrasound parameters describing the fetal brain: late biparietal diameter (R²=0.512, p=0.009), late head circumference (R²=0.498, p=0.001), middle biparietal diameter (R²=0.819, p=0.013), middle cerebellum transverse diameter R²=0.76, p=0.014) and early biparietal diameter(R²=0.819, p=0.013). The same analysis revealed that birth weight as well as ultrasound parameters such as abdominal circumference and femur length were not correlated to maternal cortisol levels. In conclusion, our study demonstrates that maternal cortisol secretion within physiological ranges may be inversely correlated to fetal brain growth but not to birth weight. It remains to be demonstrated whether maternal cortisol secretion negatively influencing fetal brain growth translates to adverse neurological outcomes in later life.

Children with Cushing's syndrome: Primary Pigmented Nodular Adrenocortical Disease should always be suspected

Primary Pigmented Nodular Adrenocortical Disease (PPNAD) is a rare form of bilateral adrenocortical hyperplasia that is inherited in an autosomal dominant manner and leads to ACTH-independent Cushing's syndrome (CS). PPNAD may be isolated or associated with Carney Complex (CNC). For the diagnosis of PPNAD and CNC, in addition to the hormonal and imaging tests, searching for PRKAR1A mutations may be recommended. The aims of the present study are to discuss the clinical and molecular findings of two Brazilian patients with ACTH-independent CS due to PPNAD and to show the diagnostic challenge CS represents in childhood. Description of two patients with CS and the many sequential steps for the diagnosis of PPNAD is provided. Sequencing analysis of all coding exons of PRKAR1A in the blood, frozen adrenal nodules (patients 1 and 2) and testicular tumor (patient 1) is performed. After several clinical and laboratory drawbacks that misled the diagnostic investigation in both patients, the diagnosis of PPNAD was finally established and confirmed through pathology and molecular studies. In patient 1, sequencing of PRKAR1A gene revealed a novel heterozygous 10-bp deletion in exon 3, present in his blood, adrenal gland and testicular tumor. The etiologic diagnosis of endogenous CS in children is a challenge that requires expertise and a multidisciplinary collaboration for its prompt and correct management. Although rare, PPNAD should always be considered among the possible etiologies of CS, due to the high prevalence of this disease in this age group.

Cushing's syndrome secondary to isolated micronodular adrenocortical disease (iMAD) associated with rapid onset weight gain and negative abdominal MRI findings in a 3 year old male

Cushing's syndrome (CS) is uncommon in childhood. CS may be either dependent or independent of adrenocorticotrophic hormone (ACTH). ACTH independent micronodular adrenocortical (MAD) disease may present in the second to third decade of life or between ages 2-3 years. It may occur in isolation, or as a part of the Carney complex and it represents an elusive entity to diagnose. We present a 3 year 7 month old boy with isolated MAD (iMAD). Abdominal CT revealed prominent mildly lobulated anteromedial margin of adrenals with nodular appearance. Cardiac echo, thyroid and testicular ultrasounds performed as a work up for Carney complex were normal. Bilateral adrenalectomy confirmed MAD as the cause of CS.We present the history and identification of a unique case of iMAD.

Cushing's disease

Cushing's syndrome refers to the clinical manifestations induced by chronic exposure to excess glucocorticoids. There are three pathological conditions that can result in the chronic overproduction of endogenous cortisol in man: the most frequent is Cushing's disease where adrenocorticotropic hormone (ACTH) is overproduced by a pituitary corticotroph adenoma, rarely ACTH can be produced in an 'ectopic' manner by a non-pituitary tumour, finally cortisol can be directly over-secreted by one or (rarely) the two adrenals that have become tumourous, either benign or malignant. The positive diagnosis of Cushing's syndrome requires that chronic hypercortisolism is unequivocally demonstrated biologically, using 24-h urinary cortisol, late-evening plasma or salivary cortisol, midnight 1-mg or the classic 48-h-low-dose dexamethasone suppression test, etc., all with essentially the same diagnosis potencies. The search for the responsible tumour then relies on the assessment of the corticotroph function, and imaging: suppressed ACTH plasma levels indicate an 'adrenal' Cushing, and the responsible unilateral adrenocortical tumour is always visible at computed tomography (CT) scan, whereas its benign or malignant nature may be difficult to diagnose before surgery. Imaging can suspect bilateral 'adrenal' Cushing, when the two adrenals are small, as in the primary pigmented nodular adrenal dysplasia associated with Carney complex, or enlarged, as in the ACTH-independent macronodular adrenocortical hyperplasia. Measurable or increased ACTH plasma levels indicate either Cushing's disease or the ectopic ACTH syndrome. When the dynamics of the corticotroph function (high-dose dexamethasone suppression test, the CRH test) are equivocal, and/or the imaging is non-contributive, it may be difficult to distinguish between the two. This is the situation where sampling ACTH plasma levels in the inferior petrosal sinus may be necessary. The best treatment option of Cushing's disease is when the responsible corticotroph adenoma can be entirely removed by the trans-sphenoidal approach, with sufficient skill to preserve the normal anterior pituitary function. When it fails, all other options directed towards the pituitary (radiation therapies), or the adrenals (medications or surgery), have numerous side effects. There is at present no recognised efficient medical treatment towards the corticotroph adenoma -still an orphan disease.