Undetectable Plasma ACTH Research Articles

Ovarian steroid cell tumor, not otherwise specific, causes Cushing syndrome in 6 years old girl: A case report

We report a case of 6 years old girl with ovarian Steroid Cell Tumor, Not Otherwise Specific (SCT-NOS). She was admitted to the hospital with increased weight gain, hypertrichosis, and cushingoid facies in form of prominent cheecks, moon facies with dorsocervical fat pad, obese built, acanthosis nigricans on back of neck and marked hirsutism. Initial workup showed raised level if cortisol with loss of diurnal rhythm, and undetectable Plasma ACTH levels, increased testosterone levels. Ultrasound revealed left sided adnexal mass having no flow inside, which was later confirmed on CT as neoplastic lesion of left ovary measuring 6.9 X 8.1 X 4.9 cm. The patient underwent left oophorectomy and pathological examination showed steroid cell tumour, limited to ovary and negative for malignancy. She was kept on IV hydrocortisone preop and post operatively and antihypertensives. After tumor resection her testosterone and cortisol returned to normal levels. Keywords: steroid cell tumor; not otherwise specific; cushing syndrome; ovarian mass.

Deksametazon Süpresyon Testlerinin Hiperkortizolizm Ayırıcı Tanısında Kullanımı

Dexamethasone suppression tests (DST) are practical, cheap and safe tests which are used to evaluate endogenous hypercortisolism. They are based on the principle that glucocorticoids exogenously given at supraphysiological doses suppress the production of CRH, ACTH and cortisol by binding to central glucocorticoid receptors. Lack of suppression of cortisol production suggest endogenous hypercortisolism. Additionally, DST may be used in the diagnosis of glucocorticoid remediable hyperaldosteronism. Due to strong glucocorticoid activity, lack of mineralocorticoid activity and lack of cross-reaction with the measurement of cortisol, dexamethasone is the preferred drug for the tests. As a screening tool in endogenous hypercortisolism, overnight 1 mg DST is used. If screening test is negative, hypercortisolism is excluded; but if the test is positive, 2-day 2 mg DST should be performed to confirm the diagnosis of Cushing’s syndrome. If endogenous hypercortisolism is confirmed, plasma ACTH should be measured. Undetectable plasma ACTH level suggest ACTH-independent Cushing’s syndrome, but inappropriately normal or high plasma ACTH level suggest ACTH-dependent Cushing’s syndrome. High dose DST (overnight 8 mg or 2-day 8 mg) should be performed to discriminate pituitary or extra-pituitary cause in the patients with ACTH-dependent Cushing’s syndrome. In the presence of pituitary Cushing’s disease, because of relatively preserved negative feedback mechanism, high dose dexamethasone may suppress ACTH. In ectopic ACTH secretion, due to lack of a normal negative feedback mechanism, ACTH cannot be suppressed by high dose dexamethasone. Extraordinarily, ectopic ACTH production in some neuroendocrine tumors may be suppressed by high dose dexamethasone, but no suppression may be observed in some patients with pituitary Cushing’s disease. When applying DST, serum and plasma samples should be collected in appropriate route, and they should be transferred by true collection tubes and in right storage conditions.

Severe Hypoglycemia due to Isolated ACTH Deficiency in Children: A New Case Report and Review of the Literature

Isolated ACTH deficiency causes life-threatening severe hypoglycemia. A 7-year-old girl with hypoglycemia due to this rare disorder is described. Our patient had undetectable plasma ACTH repeatedly and cortisol 0 mcg/dl before and after ACTH 1-24 stimulation. There was no evidence of other pituitary hormone deficiency. Glucocorticoid replacement therapy resulted in resolution of all symptoms and normalization of blood glucose. Previously published data on isolated ACTH deficiency in children is summarized. Review of the literature showed that the prevalence of this condition could be underestimated in the neonatal period and in Prader-Willi syndrome. Isolated ACTH deficiency occurs in older children as well as in neonates.

A Case of Adrenocorticotropin-independent Bilateral Adrenal Macronodular Hyperplasia (AIMAH) with Primary Hyperparathyroidism (PHPT)

We report a rare case of ACTH-independent macronodular adrenal hyperplasia (AIMAH) with primary hyperparathyroidism (PHPT). A 57-year-old woman was admitted to our hospital for further examination of secondary hypertension and bilateral adrenal macrotumors. Midnight serum cortisol elevation with undetectable plasma ACTH, increased 24-hour urinary free cortisol excretion, and loss of the normal circadian rhythm in cortisol secretion established the diagnosis of Cushing's syndrome. Total resection of the enlarged left adrenal gland was performed with subsequent steroid replacement. Her general condition improved but serum calcium level increased 3 weeks after surgery. PHPT was diagnosed on the basis of endocrinological examination, although imaging studies failed to detect parathyroid lesion. In summary, we believe this to be the first report of a case of AIMAH with PHPT.

Clinical features, diagnosis, treatment and molecular studies in paediatric Cushing's syndrome due to primary nodular adrenocortical hyperplasia

Primary nodular adrenocortical hyperplasia (PNAH) is a well recognized, but infrequently studied cause of paediatric Cushing's syndrome (CS). To assess presentation, diagnosis, radiological imaging, treatment and molecular analysis of patients with childhood-onset CS due to PNAH. Four males and two females (median age 12.9 years, range 10.9-16.9 years) were studied. All had growth failure (mean height SDS -1.2; range -2.5-0.0), weight gain [mean body mass index (BMI) SDS 3.5; range 2.5-4.6] and clinical virilization, while five had hypertension [mean systolic blood pressure (SBP) 130 mmHg, diastolic blood pressure (DBP) 83 mmHg]. One patient had generalized lentigines, one had a tibial chondromyxomatous cyst and two had facial freckling. One patient had a family history of primary nodular adrenocortical disease. The diagnosis of CS was based on elevation of sleeping midnight serum cortisol and urinary free cortisol excretion, and impaired suppression of cortisol on both low- and high-dose dexamethasone suppression tests (DST). All patients had undetectable plasma ACTH with absent responses of both plasma ACTH and serum cortisol to an intravenous (i.v.) corticotrophin-releasing hormone (CRH) test. Computed tomography or magnetic resonance imaging showed normal or small adrenals, with nodules in two patients. All patients underwent bilateral adrenalectomy, performed by open (n = 2) or laparoscopic surgery (n = 4) at a mean of 0.4 years (range 0.2-0.8 years) from diagnosis. Hypercortisolaemia was treated preoperatively by metyrapone alone 0.50-0.75 g/day (n = 4), metyrapone 0.75-1.50 g/day + o'p'DDD/mitotane 1-2 g/day (n = 1), or ketoconazole (n = 1). Adrenal histology showed nodular cortical hyperplasia with shrinkage of intervening cortical tissue and pigmentation, present in four patients. Molecular analysis of the type 1-alpha regulatory subunit of protein kinase A (PRKAR1A) gene revealed a novel germline mutation in one patient. Postadrenalectomy, three patients, had catch-up growth with height velocities increasing from 3.0, 3.9 and 2.5-8.9, 8.3 and 9.0 cm/years, respectively. All six are well at a follow-up (mean 4.0 years; range 0.5-10.8 years). PNAH was associated with cushingoid features, virilization and hypertension with a lack of cortisol suppression on high DST, undetectable plasma ACTH and absent cortisol and ACTH responses to CRH. Adrenals were normal or small on imaging. PRKAR1A gene analysis may be helpful in the assessment of these patients.

Advances in the diagnosis and treatment of Cushing's syndrome

Excess endogenous glucocorticoid production, whether ACTH-dependent or ACTH-independent, results in the classic clinical and biochemical picture of Cushing's syndrome. The diagnosis requires demonstration of an increased cortisol secretion rate, best achieved using determination of urinary free cortisol as an index. In mild cases, distinction from the hypercortisolism of pseudo-Cushing states may prove difficult. If the physician is in doubt, a dexamethasone/CRH test should be performed. Primary adrenal Cushing's syndrome can be diagnosed on the basis of undetectable plasma ACTH and the results of adrenal imaging procedures. ACTH-dependent Cushing's syndrome can be differentiated using an oCRH test and imaging procedures. In the presence of a discrete pituitary lesion on imaging, a standard oCRH test with results consistent with such a lesion is sufficient to proceed to transsphenoidal surgery. In the absence of such a lesion or if the oCRH test is equivocal, simultaneous BIPSS with oCRH administration should be performed to distinguish between a pituitary or ectopic source. Surgical ablation is the treatment of choice for all types of Cushing's syndrome. In the 5% of cases with Cushing's disease in whom transsphenoidal surgery fails and in the 5% of cases in whom the disease recurs, repeat transsphenoidal surgery or radiation therapy in association with mitotane treatment are reasonable alternatives. Bilateral adrenalectomy effectively cures hypercortisolism if resection of the ACTH-secreting tumour is unsuccessful and radiation/medical therapy fails.

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.