Cushing Syndrome in a Young Woman Due to Primary Pigmented Nodular Adrenal Disease

ObjectiveTo report a case of Cushing syndrome due to apparently sporadic primary pigmented nodular adrenal disease in a young woman.MethodsWe describe the clinical, biochemical, radiologic, and histologic findings of Cushing syndrome due to the rare condition of primary pigmented nodular adrenal disease.ResultsA 30-year-old woman presented with a 2-year history of worsening itch without rash over her shoulders and arms and weight gain, particularly around the abdomen and face. Careful questioning did not elicit any history of exogenous glucocorticoid use (systemic or topical), including hydrocortisone. On examination, the patient had a slightly rounded and plethoric face, a small buffalo hump, central adiposity, and thin skin with a few small striae on her inner thighs. No features of the Carney complex were observed. Investigations showed hypercor- tisolism with suppressed corticotropin and normal adrenal imaging despite documentation of enlarged adrenal glands at removal. High-dose dexamethasone administration was followed by a decrease in urinary free cortisol excretion rather than a paradoxical rise as previously reported in primary pigmented nodular adrenal disease. No mutations were detected in the PRKAR1A gene.ConclusionsPrimary pigmented nodular adrenal disease should be suspected in patients with corticotropinindependent Cushing syndrome who have normal adrenal imaging. The role of genetic testing in apparently sporadic cases is not established, but cumulative experience may be helpful in defining the frequency of PRKAR1A mutations. (Endocr Pract. 2010;16:84-88)     

Human tumors associated with Carney complex and germline PRKAR1A mutations: a protein kinase A disease!

Carney complex (CNC) is a multiple neoplasia syndrome that consists of endocrine (thyroid, pituitary, adrenocortical and gonadal), non-endocrine (myxomas, nevi and other cutaneous pigmented lesions), and neural (schwannomas) tumors. Primary pigmented nodular adrenocortical disease (PPNAD) is the most common endocrine manifestation of CNC and the only inherited form of Cushing syndrome known to date. In the search of genes responsible for CNC, two chromosomal loci were identified; one (17q22-24) harbored the gene encoding the type I-alpha regulatory subunit (RIalpha) of protein kinase A (PKA), PRKAR1A, a critical component of the cAMP signaling pathway. Here we review CNC and the implications of this discovery for the cAMP and/or PKA's involvement in human tumorigenesis.     

Protein kinase a alterations in endocrine tumors

Various molecular and cellular alterations of the cyclic adenosine monophosphate (cAMP) pathway have been observed in endocrine tumors. Since protein kinase A (PKA) is a central key component of the cAMP pathway, studies of the alterations of PKA subunits in endocrine tumors reveal new aspects of the mechanisms of cAMP pathway alterations in human diseases. So far, most alterations have been observed for the regulatory subunits, mainly PRKAR1A and to a lower extent, PRKAR2B. One of the best examples of such alteration today is the multiple neoplasia syndrome Carney complex (CNC). The most common endocrine gland manifestations of CNC are pituitary GH-secreting adenomas, thyroid tumors, testicular tumors, and ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). Heterozygous germline inactivating mutations of the PKA regulatory subunit RIα gene (PRKAR1A) are observed in about two-third of CNC patients, and also in patients with isolated PPNAD. PRKAR1A is considered as a tumor suppressor gene. Interestingly, these mutations can also be observed as somatic alterations in sporadic endocrine tumors. More than 120 different PRKAR1A mutations have been found today. Most of them lead to an unstable mutant mRNA, which will be degraded by nonsense mediated mRNA decay. In vitro and in vivo functional studies are in progress to understand the mechanisms of endocrine tumor development due to PKA regulatory subunits inactivation. PRKAR1A mutations stimulate in most models PKA activity, mimicking in some way cAMP pathway constitutive activation. Cross-talks with other signaling pathways summarized in this review have been described and might participate in endocrine tumorigenesis.     

Cushing's Syndrome and Fetal Features Resurgence in Adrenal Cortex–Specific Prkar1a Knockout Mice

Carney complex (CNC) is an inherited neoplasia syndrome with endocrine overactivity. Its most frequent endocrine manifestation is primary pigmented nodular adrenocortical disease (PPNAD), a bilateral adrenocortical hyperplasia causing pituitary-independent Cushing''s syndrome. Inactivating mutations in PRKAR1A, a gene encoding the type 1 α-regulatory subunit (R1α) of the cAMP–dependent protein kinase (PKA) have been found in 80% of CNC patients with Cushing''s syndrome. To demonstrate the implication of R1α loss in the initiation and development of PPNAD, we generated mice lacking Prkar1a specifically in the adrenal cortex (AdKO). AdKO mice develop pituitary-independent Cushing''s syndrome with increased PKA activity. This leads to autonomous steroidogenic genes expression and deregulated adreno-cortical cells differentiation, increased proliferation and resistance to apoptosis. Unexpectedly, R1α loss results in improper maintenance and centrifugal expansion of cortisol-producing fetal adrenocortical cells with concomitant regression of adult cortex. Our data provide the first in vivo evidence that loss of R1α is sufficient to induce autonomous adrenal hyper-activity and bilateral hyperplasia, both observed in human PPNAD. Furthermore, this model demonstrates that deregulated PKA activity favors the emergence of a new cell population potentially arising from the fetal adrenal, giving new insight into the mechanisms leading to PPNAD.     

Adrenal pathophysiology: lessons from the Carney complex

The Carney complex (CNC) is a dominantly inherited syndrome responsible mainly for spotty skin pigmentation (lentiginosis), endocrine overactivity, and cardiac myxomas. Adrenocorticotropic hormone independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD) is a main characteristic of CNC. PPNAD is a very rare cause of Cushing's syndrome due to a primary bilateral adrenal defect that can be also observed in some patients without other CNC manifestations nor familial history. One of the putative CNC genes, located on 17q22-24, has been identified as the regulatory subunit R1A of protein kinase A (PRKAR1A). Heterozygous inactivating mutations of PRKAR1A have been reported initially in about 45% of the CNC index cases and could be found in about 80% of the CNC families presenting mainly with Cushing's syndrome. PRKAR1A is a key component of the cyclic AMP signaling pathway that has been implicated in endocrine tumorigenesis and could, at least partly, function as a tumor suppressor gene. Interestingly, patients with isolated PPNAD and no familial history of CNC can also present a germline de novo mutation of PRKAR1A. Somatic mutations of PRKAR1A have been found in PPNAD as a mechanism of inactivation of the wild-type allele, in a patient already presenting a germline mutation, and in a subset of sporadic secreting adrenocortical adenomas with clinical, hormonal, and pathological features quite similar to PPNAD. This review will summarize the recent findings on CNC from the perspective of the pathophysiology of adrenal Cushing's syndrome and PPNAD.     

Genetic Basis of Bilateral Macronodular Hyperplasia

Objective: To review the genetic basis of bilateral macronodular hyperplasia (BMAH).Methods: Case presentation, review of literature, table, and bullet point conclusions.Results: BMAH, also known as adrenocorticotropic hormone (ACTH)-independent macronodular hyperplasia (AIMH), can cause Cushing syndrome or mild hypercortisolism. Recent studies have demonstrated that hyperplastic tissue reproduces ectopic ACTH, implying that BMAH is the more proper term, as the syndrome is not ACTH-independent. BMAH was thought to be sporadic, but recent data have shown that there is likely a genetic component in the majority of cases. Mutations in ARMC5, a putative suppressor gene, have been found in many familial cases of BMAH and are thought to be responsible for the disorder. As these nodules inefficiently produce cortisol, large nodules are required to produce a clinical syndrome. ARMC5 likely requires a second somatic mutation to become clinically apparent. Clinical manifestations are not generally noted until the fifth to sixth decades of life.Conclusion: BMAH is an underrecognized genetic condition that can lead to Cushing syndrome and should be screened for in patients and susceptible family members.Abbreviations: ACTH = adrenocorticotropic hormone AIMAH = ACTH-independent macronodular adrenal hyperplasia ARMC5 = armadillo-repeat containing 5 BMAH = bilateral macronodular adrenal hyperplasia CAH = congenital adrenal hyperplasia CT = computed tomography MEN1 = multiple endocrine neoplasia 1 UFC = urinary free cortisol     

An Unusual Variant of Cushing Syndrome

ObjectiveTo discuss the initial clinical manifestations of primary pigmented nodular adrenocortical disease.MethodsWe present a case report of a 4-year-old boy who had the classic clinical features of Cushing syndrome. Results of hormonal investigations are reviewed, and histopathologic findings are illustrated.ResultsInvestigations revealed adrenocorticotropic hormone (corticotropin)-independent Cushing syndrome. Findings on magnetic resonance imaging of the pituitary gland and abdomen were within normal limits. The patient underwent bilateral adrenalectomy. The histopathologic features were consistent with primary pigmented nodular adrenocortical disease.ConclusionPrimary pigmented nodular adrenocortical disease should be suspected in patients with corticotropin- independent Cushing syndrome who have normal findings on adrenal imaging. (Endocr Pract. 2008;14:717-720)     

Pathogenesis of Cushing Disease: An Update on the Genetics of Corticotropinomas

Objective: Cushing disease is a rare severe condition caused by pituitary tumors that secrete adrenocorticotropic hormone (ACTH), leading to excessive endogenous glucocorticoid production. Tumors causing Cushing disease, also called corticotropinomas, are typically monoclonal neoplasms that mainly occur sporadically.Methods: Literature review.Results: Cushing disease is very rarely encountered in genetic familial syndromes. Oncogenes and tumor suppressor genes commonly associated with other tumor types are only rarely mutated in this tumor type. The advent of next-generation sequencing led to the identification of a single mutational hotspot in the ubiquitin-specific protease 8 (USP8) gene in almost half of Cushing disease tumors.Conclusion: The new discoveries showcase a novel mechanism responsible for corticotroph tumorigenesis and ACTH hypersecretion and highlight USP8 and its downstream signaling pathways as potential promising pharmacologic targets for the management of Cushing disease.Abbreviations: ACTH = adrenocorticotropic hormone; BRG1 = Brahma-related gene 1; CABLES1 = CDK5 and ABL1 enzyme substrate 1; CD = Cushing disease; CNC = Carney complex; DICER1 = cytoplasmic endoribonuclease III; EGFR = epidermal growth factor receptor; GR = glucocorticoid receptor; IL = interleukin; MEN = multiple endocrine neoplasia; miRNA = microRNA; POMC = proopiomelanocortin; SSTR = somatostatin receptor; USP8 = ubiquitin-specific protease 8     

Functional Characterization of PRKAR1A Mutations Reveals a Unique Molecular Mechanism Causing Acrodysostosis but Multiple Mechanisms Causing Carney Complex

The main target of cAMP is PKA, the main regulatory subunit of which (PRKAR1A) presents mutations in two genetic disorders: acrodysostosis and Carney complex. In addition to the initial recurrent mutation (R368X) of the PRKAR1A gene, several missense and nonsense mutations have been observed recently in acrodysostosis with hormonal resistance. These mutations are located in one of the two cAMP-binding domains of the protein, and their functional characterization is presented here. Expression of each of the PRKAR1A mutants results in a reduction of forskolin-induced PKA activation (measured by a reporter assay) and an impaired ability of cAMP to dissociate PRKAR1A from the catalytic PKA subunits by BRET assay. Modeling studies and sensitivity to cAMP analogs specific for domain A (8-piperidinoadenosine 3′,5′-cyclic monophosphate) or domain B (8-(6-aminohexyl)aminoadenosine-3′,5′-cyclic monophosphate) indicate that the mutations impair cAMP binding locally in the domain containing the mutation. Interestingly, two of these mutations affect amino acids for which alternative amino acid substitutions have been reported to cause the Carney complex phenotype. To decipher the molecular mechanism through which homologous substitutions can produce such strikingly different clinical phenotypes, we studied these mutations using the same approaches. Interestingly, the Carney mutants also demonstrated resistance to cAMP, but they expressed additional functional defects, including accelerated PRKAR1A protein degradation. These data demonstrate that a cAMP binding defect is the common molecular mechanism for resistance of PKA activation in acrodysosotosis and that several distinct mechanisms lead to constitutive PKA activation in Carney complex.     

Long-Term Management with Octreotide or Cabergoline in Ectopic Corticotropin Hypersecretion: Case Report and Literature Review

ObjectiveTo describe the corticotropin response to long-term octreotide or cabergoline administration in a patient with ectopic corticotropin secretion who underwent adrenalectomy.MethodsWe describe the clinical, radiologic, and biochemical findings of the study patient over the course of 18 years.ResultsA 40-year-old woman was evaluated for Cushing syndrome. On the basis of biochemical indices, Cushing disease was diagnosed and pituitary exploration was performed. No cure was achieved. Computed tomography of the chest revealed a right lung nodule due to a lung carcinoid tumor that was then surgically excised. Because of persistent hypercortisolism, total adrenalectomy was performed. Subsequently, corticotropin levels rose dramatically and hyperpigmentation developed while serum cortisol was in the reference range. The patient was treated with octreotide for 3 years and then with cabergoline for 8 years. While taking octreotide, corticotropin values decreased, accompanied by depigmentation and development of signs of adrenal insufficiency, which led to the reinstitution of supplemental hydrocortisone. Cabergoline induced a similar long-lasting effect on the clinical and biochemical parameters observed. Eight years later, she is still treated with cabergoline, and no lung tumor has been detected.ConclusionsIn this patient with ectopic Cushing syndrome, treatment with either octreotide or cabergoline markedly reduced corticotropin levels and hyperpigmentation. (Endocr Pract. 2010;16:829-834)     

Severe Ectopic Cushing Syndrome Caused by Adenoid Cystic Carcinoma of a Salivary Gland

ObjectiveWe present a rare case of Cushing syndrome due to ectopic adrenocorticotropic hormone (ACTH) secretion (EAS). To our knowledge only two similar cases have been previously reported.MethodsThis is a case report of EAS by a metastatic lingual adenoid cystic carcinoma (ACC).ResultsThe patient was diagnosed of a Cushing syndrome caused by tumoral EAS two years after initial cancer diagnosis. Clinical presentation included asthenia, insomnia, hypertension, acne, and hyperpigmentation developing in a period of two months. Laboratory and imaging testing revealed hypokalemic metabolic alkalosis, hypercortisole- mia, high ACTH, nonsuppresion by 8 mg dexamethasone, and a normal pituitary magnetic resonance imaging (MRI). With a high clinical suspicion of EAS, combined medical treatment was started but was unsuccessful. Bilateral adrenalectomy could not be performed given the patient’s rapid deterioration. Immunostained tissue from the original tumor was positive for synaptophysin.ConclusionThis rare case of EAS illustrates the challenge that this condition may confer regarding diagnosis and management. (Endocr. Pract. 2013;19:e118-e121)     

Molecular analysis of the cyclic AMP-dependent protein kinase A (PKA) regulatory subunit 1A (PRKAR1A) gene in patients with Carney complex and primary pigmented nodular adrenocortical disease (PPNAD) reveals novel mutations and clues for pathophysiology: augmented PKA signaling is associated with adrenal tumorigenesis in PPNAD

We studied 11 new kindreds with primary pigmented nodular adrenocortical disease (PPNAD) or Carney complex (CNC) and found that 82% of the kindreds had PRKAR1A gene defects (including seven novel inactivating mutations), most of which led to nonsense mRNA and, thus, were not expressed in patients' cells. However, a previously undescribed base substitution in intron 6 (exon 6 IVS +1G-->T) led to exon 6 skipping and an expressed shorter PRKAR1A protein. The mutant protein was present in patients' leukocytes and tumors, and in vitro studies indicated that the mutant PRKAR1A activated cAMP-dependent protein kinase A (PKA) signaling at the nuclear level. This is the first demonstration of an inactivating PRKAR1A mutation being expressed at the protein level and leading to stimulation of the PKA pathway in CNC patients. Along with the lack of allelic loss at the PRKAR1A locus in most of the tumors from this kindred, these data suggest that alteration of PRKAR1A function (not only its complete loss) is sufficient for augmenting PKA activity leading to tumorigenesis in tissues affected by CNC.     

Virilizing Ovarian Leydig Cell Tumor in A Woman with Subclinical Cushing Syndrome

ObjectiveTo report the case of a patient with a virilizing ovarian Leydig cell tumor and subclinical Cushing syndrome attributable to an adrenal adenoma.MethodsDetailed clinical, laboratory, radiologic, and pathologic findings are presented, and the pertinent literature is reviewed.ResultsA 49-year-old woman was referred for evaluation of a left adrenal mass (3.0 by 2.4 cm), which had been diagnosed by computed tomographic scan 4 years previously during a work-up for hirsutism. On examination, she had central obesity, facial hirsutism, and male pattern baldness. Work-up showed elevated total and free testosterone levels of 196 ng/dL (reference range, 20 to 70) and 24 pg/mL (1 to 9), respectively. Other results (and reference ranges) were as follows: dehydroepiandrosterone sulfate, 7.5 μg/dL (10 to 221); corticotropin, 12 pg/mL (5 to 50); morning cortisol, 1.4 μg/dL after a 1-mg overnight dexamethasone suppression test; and urine free cortisol, 48.8 μg/24 h (20 to 100). The testosterone level decreased by 14% after a 2-day low-dose dexamethasone suppression test. Findings on transvaginal ovarian ultrasonography and a computed tomographic scan of the pelvis were normal. A laparoscopic adrenalectomy revealed an adrenal adenoma. On the first day postoperatively, the cortisol level was less than 1.0 μg/dL; however, the testosterone level remained elevated. At 6 months postoperatively, a normal result of a cosyntropin stimulation test indicated recovery of the hypothalamic-pituitaryadrenal axis. Bilateral oophorectomy revealed a 1.3-cm right ovarian Leydig cell tumor. Postoperatively, the testosterone level declined to less than 20 ng/dL.ConclusionTo our knowledge, this is the first case report of a virilizing ovarian Leydig cell tumor in a patient with subclinical Cushing syndrome. (Endocr Pract. 2008;14:358-361)     

Systemic embolisation as presentation and recurrence of cardiac myxoma two years after surgery

Primary cardiac tumours are rare when compared with metastatic involvement. The majority of primary cardiac tumours are benign and in adults the majority of these masses are myxomas. The treatment is surgical removal because of the risk of embolisation and/or cardiovascular complications. We describe a female presenting with systemic embolisation and recurrence of cardiac myxoma after surgery. Recurrence of myxoma is rare after surgery in case of solitary tumours but more frequent in patients with familial myxomas in association with the Carney complex. Genetic analysis revealed a mutation in the PRKAR1A gene that has never been described before. (Neth Heart J 2010;18:499-502.)     

Phosphodiesterase 11A expression in the adrenal cortex, primary pigmented nodular adrenocortical disease, and other corticotropin-independent lesions.

A variety of adrenal tumors and bilateral adrenocortical hyperplasias (BAH) leading to Cushing syndrome (CS) may be caused by aberrant cAMP signaling. We recently identified patients with a micronodular form of BAH that we have called "isolated micronodular adrenocortical disease" (iMAD) in whom CS was associated with inactivating mutations in phosphodiesterase (PDE) 11A ( PDE11A). In the present study, we examined PDE11A expression in normal adrenocortical tissue, sporadic tumors, and hyperplasias without PDE11A mutations, and primary pigmented nodular adrenocortical disease (PPNAD) and adenomas from patients with PRKAR1A and a single tumor with a GNAS mutation. The total number of the tumor samples that we studied was 22. Normal human tissues showed consistent PDE11A expression. There was variable expression of PDE11A in sporadic adrenocortical hyperplasia or adenomas; PPNAD tissues from patients with PRKAR1A mutations expressed consistently high levels of PDE11A in contrast to adenomas caused by GNAS mutations. Phosphorylated CREB was the highest in tissues from patients with iMAD compared to all other forms of BAH and normal adrenal tissue. We conclude that PDE11A is expressed widely in adrenal cortex. Its expression appears to be increased in PPNAD but varies widely among other adrenocortical tumors. PRKAR1A expression appears to be higher in tissues with PDE11A defects. Finally, sequencing defects in PDE11A are associated with a high state of CREB phosphorylation, just like PRKAR1A mutations. These preliminary data suggest that these two molecules are perhaps regulated in a reverse manner in their control of cAMP signaling in adrenocortical tissues.     

Bilateral Adrenalectomy: Lifesaving Procedure in Severe Cushing Syndrome

ObjectiveTo discuss the role of bilateral adrenalectomy in Cushing syndrome, as illustrated in a case of severe hypercortisolism that was unresponsive to combination agent medical therapy.MethodsWe report the clinical, laboratory, imaging, and pathologic findings in a patient with ectopic Cushing syndrome attributable to an adrenocorticotropic hormone (ACTH)-secreting neuroblastoma. In addition, we provide a literature review regarding olfactory neuroblastoma and discuss current and emerging therapeutic options for Cushing syndrome.ResultsA 59-year-old man presented with nasal congestion and neck swelling and was noted to have hypokalemia, hypertension, and hyperglycemia. A nasal biopsy demonstrated a poorly differentiated carcinoma with neuroendocrine features. He was subsequently diagnosed as having ACTH-dependent Cushing syndrome, but despite high-dose combination medical therapy, his condition rapidly deteriorated. Urgent bilateral adrenalectomy provided rapid control of the hypercortisolism, and the patient was later able to undergo an uncomplicated total macroscopic resection of his locally metastatic primary tumor.ConclusionThis report describes the challenges in the diagnosis and management of ACTH-dependent Cushing syndrome and highlights the important role that bilateral adrenalectomy can still have in patients with severe hypercortisolism causing life-threatening complications. (Endocr Pract. 2012;18:e85-e90)     

Unusual Cause of Ectopic Secretion of Adrenocorticotropic Hormone: Cushing Syndrome Attributable to Small Cell Prostate Cancer

ObjectiveTo report a rare cause of ectopic adrenocorticotropic hormone (ACTH) secretion leading to severe Cushing syndrome.MethodsWe describe the clinical presentation and management of a case of Cushing syndrome attributable to ectopic ACTH secretion from small cell cancer of the prostate.ResultsIn a 70-year-old man with hypertension and diabetes, congestive heart failure developed. He was found to have severe hypokalemia (serum potassium, 1.7 mEq/L) and a huge pelvic mass on a computed tomographic scan performed because of a complaint of urinary retention. Transurethral biopsy of the prostate showed features of small cell prostate cancer. Hormonal evaluation revealed a high urine free cortisol excretion of 6,214.5 μg/d (reference range, 36 to 137), confirming the diagnosis of Cushing syndrome. A serum ACTH level was elevated at 316 ng/dL (reference range, 10 to 52). An overnight highdose (8 mg orally) dexamethasone suppression test was positive (serum cortisol levels were 43.2 and 41 μg/dL before and after suppression, respectively), and magnetic resonance imaging of the pituitary gland disclosed no abnormalities. A prostate biopsy specimen showed small cell prostate cancer with positive staining for ACTH. The tumor was found to be unresectable, and the poor condition of the patient did not allow for bilateral adrenalectomy. He was treated with ketoconazole and metyrapone, which yielded good temporary control of his Cushing syndrome (24-hour urine free cortisol decreased to 55.2 μg/d). He received 1 cycle of chemotherapy (etoposide and cisplatin), but he died 6 months later as a result of sepsis.ConclusionSmall cell prostate cancer is a rare subtype that can be associated with ectopic secretion of ACTH and severe Cushing syndrome. With this subtype of prostate cancer, Cushing syndrome should be considered and appropriately managed. (Endocr Pract. 2010;16:249-254)     

Diagnosis by Serendipity: Cushing Syndrome Attributable to Cortisol-Producing Adrenal Adenoma as the Initial Manifestation of Multiple Endocrine Neoplasia Type 1 Due to a Rare Splicing Site Men1 Gene Mutation

ObjectiveTo report a case that highlights the potential for Cushing syndrome to be the first manifestation of multiple endocrine neoplasia type 1 (MEN 1) syndrome and to describe the rare underlying genetic mutation and the heterogeneous manifestations of the syndrome within the same family.MethodsWe present a case report including biochemical and radiologic findings, review family data, and discuss the results of genetic analyses.ResultsA 16-year-old girl who was not known to have any medical illness and had no known family history of MEN 1 syndrome presented with Cushing syndrome attributable to a cortisol-producing adrenal adenoma. During her evaluation, she was found to have primary hyperparathyroidism and a pituitary microprolactinoma. These findings raised the possibility of MEN 1 syndrome. She did not have clinical, biochemical, or radiologic evidence of islet cell pancreatic tumors. Family screening showed that her father had evidence of primary hyperparathyroidism, mild hyperprolactinemia, normal findings on magnetic resonance imaging of the pituitary, and a 1.2- cm nodule in the tail of the pancreas in conjunction with slight elevation of serum insulin and normal gastrin levels. The patient’s 5 siblings had evidence of primary hyperparathyroidism, and 2 of them also had mild hyperprolactinemia. Genetic screening confirmed the presence of a MEN1 gene missense G to A mutation in the patient, her father, and her siblings at the splicing site of intron 6 (IVS6 + 1G > A). This mutation leads to frameshift and truncation of the MEN1 gene.ConclusionIn MEN 1, Cushing syndrome is an extremely rare and usually late manifestation. Most cases are due to corticotropin-producing pituitary adenomas. Although Cushing syndrome generally develops years after the more typical manifestations of MEN 1 appear, it may be the primary manifestation of MEN 1 syndrome. There is considerable heterogeneity in the manifestations of MEN 1, even within a family having the same genetic mutation. (Endocr Pract. 2008;14:595-602)     

Corticotropin-Independent Macronodular Adrenal Hyperplasia Associated With Insulinoma

ObjectiveTo report a case of corticotropin-independent macronodular adrenal hyperplasia (AIMAH) associated with an insulinoma.MethodsWe describe the clinical, radiographic, laboratory, and histopathologic findings of the study patient; review the current protocols for management of AIMAH; and discuss the disease etiology.ResultsA 64-year-old woman with multiple intradermal facial nevi experienced intermittent light-headedness, tremor, and confusion and was found to have a venous plasma glucose concentration of 52 mg/dL. Hypoglycemia and hyperinsulinemia after 18 hours of fasting suggested the presence of an insulinoma. Hepatic venous sampling for insulin after selective arterial calcium injection localized the insulinoma to the pancreatic head. The insulinoma was excised, and there was no recurrence over the 5 years the patient was in our care. During the workup for insulinoma, bilateral adrenal masses were incidentally discovered on computed tomography. Twenty-hour urinary free cortisol excretion was elevated and serum corticotropin was suppressed. Overt signs of Cushing syndrome were not present, and subsequent urinary cortisol measurements were within the reference range for several years. After 4 years, Cushing syndrome developed and bilateral adrenalectomy was performed. AIMAH was diagnosed on the basis of histopathologic findings.ConclusionsThis appears to be the first reported case of AIMAH associated with an insulinoma. In the absence of other stigmata of multiple endocrine neoplasm type 1 and in the presence of multiple nevi, it may represent a novel endocrine syndrome. (Endocr Pract. 2011;17:e43-e47)