SUN-917 Aggressive De Novo MEN1 Variant in a Child with Metastatic Pancreatic Acth and Crh Co-Secreting Neuroendocrine Tumor: Diagnosis and 10-Year Follow Up

Background: In Multiple Endocrine Neoplasia type 1 (MEN1) only about 2% of pituitary adenomas are ACTH-secreting. Cushing Syndrome due to ectopic ACTH or CRH secretion from neuroendocrine tumors (NETs), carcinoid tumors, or pheochromocytomas is very rare, though patients with MEN1 are at increased risk for these three types of tumors, as well as autonomous adrenal secretion of cortisol. The 10-year follow up of a previously-reported case of a child with MEN1 and metastatic pancreatic ACTH/CRH-secreting NET is presented. Clinical Case: A previously-reported (J Clin Endocrinol Metab, 2015) now 21 yo female presented to the National Institutes of Health (NIH) at 11 yo with persistent hypercortisolemia despite transsphenoidal surgery for suspected Cushing Disease. However, the resected tissue revealed pituitary hyperplasia, and she remained hypercortisolemic. A CRH test was consistent with an ectopic source, and abdominal CT, PET scan, and Octreotide scan revealed a mass in the pancreatic tail. The patient underwent partial pancreatectomy at 11 yo with the resected tissue staining positive for ACTH and CRH. However, she remained hypercortisolemic, so bilateral adrenalectomy was performed. At 12 yo metastases were found, so Octreotide therapy was initiated. She continued to have elevated ACTH levels > 1000 pg/mL (5-46). Additionally, a pituitary adenoma was noted at 12 yo, which has since increased in size. The patient also developed mild primary hyperparathyroidism, first noted at 19 yo. Sequencing of MEN1 for the patient and her parents revealed a de novo heterozygous c.1546dupC variant, consistent with sporadic MEN1. The patient also had a chromosome 8p23.2 duplication that was present in unaffected relatives. Conclusion: While 2% of patients with MEN1 may develop Cushing Syndrome due to an ACTH-secreting pituitary adenoma, it is also important to consider ectopic secretion of ACTH/CRH from MEN1-associated NETs, carcinoid tumors, or pheochromocytomas, as well as autonomous adrenal secretion of cortisol. Given the early age and severe presentation of MEN1 features in this patient, the c.1546dupC heterozygous variant of MEN1, which has been previously reported in multiple other cases of MEN1, may represent a higher-risk causative variant of MEN1. Alternatively, expression of this variant may have been affected by the concurrent presence of an otherwise apparently benign chromosomal variant. References: A. Karageorgiadis, G. Papadakis, J. Biro, M. Keil, C. Lyssikatos, M. Quezado, M. Merino, D. Schrump, E. Kebebew, N. Patronas, M. Hunter, M. Alwazeer, L. Karaviti, A. Balazs, M. Lodish, and C. Stratakis. Ectopic Adrenocorticotropic Hormone and Corticotropin-Releasing Hormone Co-Secreting Tumors in Children and Adolescents Causing Cushing Syndrome: A Diagnostic Dilemma and How to Solve It. Clin Endocrinol Metab, January 2015, 100(1):141–148

Serotonergic effects on feeding, but not hypothalamus-pituitary-adrenal secretion, are altered in ovine pregnancy

In ovine pregnancy, as in human pregnancy, hypothalamus-pituitary-adrenal activity is chronically increased. These studies were designed to test the hypotheses that expression of serotonergic genes and responsiveness to serotonin are increased in pregnancy. We tested the stimulatory effect of an acute, intracerebroventricular injection of the serotonin reuptake inhibitor fluoxetine on plasma ACTH and cortisol in ewes during late pregnancy or postpartum. We also tested the effect of lower-dose, longer-term stimulation by intracerebroventricular infusion of fluoxetine in pregnant and nonpregnant ewes over 6 days. Overall, we found that the stimulatory effect of fluoxetine on ACTH and cortisol was not significantly different between late-gestation and nonpregnant ewes, although the effect of acute fluoxetine administration was inversely related to plasma progesterone concentrations. Also, there were no differences in hypothalamic expression of the glucocorticoid and mineralocorticoid receptors, corticotropin-releasing hormone, AVP, the serotonin reuptake transporter, or the serotonin [5-hydroxytryptamine (5-HT)] receptors 5-HT1A and 5-HT2A with pregnancy or fluoxetine treatment. However, chronic fluoxetine infusion reduced food intake in the nonpregnant, but not pregnant, ewes. Expression of proopiomelanocortin mRNA in the hypothalamus was reduced in pregnant compared with nonpregnant ewes. Our results indicate that pregnancy does not increase responsiveness of ACTH and cortisol to serotonergic stimulation but, rather, that progesterone reduces the ACTH response. In addition, we found a reduced ability of serotonin to inhibit feeding in the pregnant ewes, consistent with a reduction in anorexic mechanisms in the pregnant state.

Extra-adrenal glucocorticoids and mineralocorticoids: evidence for local synthesis, regulation, and function

Glucocorticoids and mineralocorticoids are steroid hormones classically thought to be secreted exclusively by the adrenal glands. However, recent evidence has shown that corticosteroids can also be locally synthesized in various other tissues, including primary lymphoid organs, intestine, skin, brain, and possibly heart. Evidence for local synthesis includes detection of steroidogenic enzymes and high local corticosteroid levels, even after adrenalectomy. Local synthesis creates high corticosteroid concentrations in extra-adrenal organs, sometimes much higher than circulating concentrations. Interestingly, local corticosteroid synthesis can be regulated via locally expressed mediators of the hypothalamic-pituitary-adrenal (HPA) axis or renin-angiotensin system (RAS). In some tissues (e.g., skin), these local control pathways might form miniature analogs of the pathways that regulate adrenal corticosteroid production. Locally synthesized glucocorticoids regulate activation of immune cells, while locally synthesized mineralocorticoids regulate blood volume and pressure. The physiological importance of extra-adrenal glucocorticoids and mineralocorticoids has been shown, because inhibition of local synthesis has major effects even in adrenal-intact subjects. In sum, while adrenal secretion of glucocorticoids and mineralocorticoids into the blood coordinates multiple organ systems, local synthesis of corticosteroids results in high spatial specificity of steroid action. Taken together, studies of these five major organ systems challenge the conventional understanding of corticosteroid biosynthesis and function.

Corticotrope hypersecretion coupled with cortisol hypo-responsiveness to stimuli is present in patients with autoimmune endocrine diseases: evidence for subclinical primary hypoadrenalism?

Objective: In autoimmune polyglandular syndrome types 1, 2, and 4 primary adrenal insufficiency is present, but its diagnosis is often late. We investigated the function of the hypothalamic–pituitary–adrenal axis in a group of patients with autoimmune diseases (AP) without any symptoms and signs of hypoadrenalism. Design: In 10 AP and 12 normal subjects (NS), we studied cortisol (F), aldosterone (A), and DHEA responses to 0.06 μg adrenocorticotropin (ACTH) (1–24) followed by 250 μg, ACTH and F responses to human corticotropin-releasing hormone (hCRH; 100 μg) and insulin tolerance test (ITT) (0.1 UI/kg). Results: Basal F, A, DHEA, as well as urinary free cortisol and plasma renin activity levels in AP and NS were similar, whereas ACTH levels in AP were higher (P<0.05) than in NS. NS showed F, A, and DHEA response to both consecutive ACTH doses. In AP, the F, A, and DHEA responses to 250 μg ACTH were similar to those in NS, whereas the 0.06 μg ACTH dose did not elicit any significant response. The ACTH responses to hCRH and ITT in AP were higher (P<0.05) than in NS. The F response to hCRH in AP was lower (P<0.05) than in NS, whereas the F response to ITT in AP did not significantly differ from NS. Conclusions: Enhancement of both basal and stimulated corticotrope secretion coupled with reduced adrenal sensitivity to low ACTH dose is present in AP patients without symptoms and signs of hypoadrenalism. This functional picture suggests that normal adrenal secretion is maintained due to corticotrope hyperfunction, suggesting the existence of some subclinical primary hypoadrenalism.

Discovering the role of the adrenal gland in the control of body function

This essay looks at the historical significance of three APS classic papers that are freely available online: Cannon WB and de la Paz D. Emotional stimulation of adrenal secretion. Am J Physiol 28: 64-70, 1911 ( http://ajplegacy.physiology.org/cgi/reprint/28/1/64 ). Cannon WB. The emergency function of the adrenal medulla in pain and the major emotions. Am J Physiol 33: 356-372, 1914 ( http://ajplegacy.physiology.org/cgi/reprint/33/2/356 ). Cannon WB. Studies on the conditions of activity in endocrine glands. V. The isolated heart as an indicator of adrenal secretion induced by pain, asphyxia and excitement. Am J Physiol 50: 399-432, 1919 ( http://ajplegacy.physiology.org/cgi/reprint/50/3/399 ).