RESUMEN
BACKGROUND Adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome (CS) secondary to an ectopic source is an uncommon condition, accounting for 4-5% of all cases of CS. Refractory hypokalemia can be the presenting feature in patients with ectopic ACTH syndrome (EAS), and is seen in up to 80% of cases. EAS can be rapidly progressive and life-threatening without timely diagnosis and intervention. CASE REPORT We present a case of a 74-year-old White woman who first presented with hypokalemia, refractory to treatment with potassium supplementation and spironolactone. She progressively developed generalized weakness, recurrent falls, bleeding peptic ulcer disease, worsening congestive heart failure, and osteoporotic fracture. A laboratory workup showed hypokalemia, hypernatremia, and primary metabolic alkalosis with respiratory acidosis. Hormonal evaluation showed elevated ACTH, DHEA-S, 24-h urinary free cortisol, and unsuppressed cortisol following an 8 mg dexamethasone suppression test, suggestive of ACTH-dependent CS. CT chest, abdomen, and pelvis, and FDG/PET CT scan showed a 1.4 cm right lung nodule and bilateral adrenal enlargement, confirming the diagnosis of EAS, with a 1.4-cm lung nodule being the likely source of ectopic ACTH secretion. Due to the patient's advanced age, comorbid conditions, and inability to attend to further evaluation and treatment, her family decided to pursue palliative and hospice care. CONCLUSIONS This case illustrates that EAS is a challenging condition and requires a multidisciplinary approach in diagnosis and management, which can be very difficult in resource-limited areas. In addition, a delay in diagnosis and management often results in rapid deterioration of clinical status.
Asunto(s)
Síndrome de ACTH Ectópico , Síndrome de Cushing , Hipopotasemia , Síndrome de ACTH Ectópico/diagnóstico , Hormona Adrenocorticotrópica , Anciano , Síndrome de Cushing/diagnóstico , Femenino , Humanos , Hidrocortisona , Hipopotasemia/etiologíaRESUMEN
An elderly gentleman was admitted to hospital with severe hypokalaemia of 1.75mmol/L. A background of a recently diagnosed metastatic gastric carcinoma with a neuroendocrine component pointed towards the diagnosis of ectopic ACTH secretion causing this dangerous electrolyte imbalance. He was treated with aggressive potassium supplementation and the adrenal steroid synthesis blocker metyrapone to acutely control his Cushing's syndrome. Chemotherapy consisting of carboplatin/etoposide combination was initiated but unfortunately the patients' health deteriorated, and he died three months after his initial diagnosis. This case highlights the accelerated presentation of hypercortisolism due to ectopic ACTH secretion. It discusses the classification of neuroendocrine tumours and their varied prognosis depending on the underlying tumour grade. It emphasises the importance of having a multidisciplinary team to be able to care for two underlying pathologies simultaneously: both the severe hypercortisolism and his metastatic gastric tumour.
Asunto(s)
Síndrome de ACTH Ectópico , Carcinoma , Síndrome de Cushing , Neoplasias Gástricas , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/etiología , Hormona Adrenocorticotrópica , Anciano , Humanos , Masculino , Neoplasias Gástricas/complicaciones , Neoplasias Gástricas/tratamiento farmacológicoRESUMEN
PURPOSE: Ectopic Cushing Syndrome (EAS) is a rare condition responsible for about 5-20% of all Cushing syndrome cases. It increases the mortality of affected patients thus finding and removal of the ACTH-producing source allows for curing or reduction of symptoms and serum cortisol levels. The aim of this study is to present a 20-year experience in the diagnosis and clinical course of patients with EAS in a single Clinical Centre in Southern Poland as well as a comparison of clinical course and outcomes depending on the source of ectopic ACTH production-especially neuroendocrine tumors with other neoplasms. METHODS: Twenty-four patients were involved in the clinical study with EAS diagnosed at the Department of Endocrinology between years 2000 and 2018. The diagnosis of EAS was based on the clinical presentation, hypercortisolemia with high ACTH levels, high dose dexamethasone suppression test and/or corticotropin-releasing hormone tests. To find the source of ACTH various imaging studies were performed. RESULTS: Half of the patients were diagnosed with neuroendocrine tumors, whereby muscle weakness was the leading symptom. Typical cushingoid appearance was seen in merely a few patients, and weight loss was more common than weight gain. Patients with neuroendocrine tumors had significantly higher midnight cortisol levels than the rest of the group. Among patients with infections, we observed a significantly higher concentrations of cortisol 2400 levels in gastroenteropancreatic neuroendocrine tumors. Chromogranin A correlated significantly with potassium in patients with neuroendocrine tumors and there was a significant correlation between ACTH level and severity of hypokalemia. CONCLUSION: EAS is not common, but if it occurs it increases the mortality of patients; therefore, it should be taken into consideration in the case of coexistence of severe hypokalemia with hypertension and muscle weakness, especially when weight loss occurs. Because the diagnosis of gastroenteropancreatic neuroendocrine tumor worsens the prognosis-special attention should be paid to these patients.
Asunto(s)
Síndrome de ACTH Ectópico , Síndrome de ACTH Ectópico/sangre , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/fisiopatología , Adolescente , Hormona Adrenocorticotrópica/sangre , Adulto , Anciano , Síndrome de Cushing/sangre , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/fisiopatología , Femenino , Humanos , Hidrocortisona/sangre , Hipertensión/sangre , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Hipopotasemia/sangre , Hipopotasemia/diagnóstico , Hipopotasemia/fisiopatología , Masculino , Persona de Mediana Edad , Debilidad Muscular/sangre , Debilidad Muscular/diagnóstico , Debilidad Muscular/fisiopatología , Polonia , Estudios RetrospectivosRESUMEN
BACKGROUND: Cushing syndrome (CS) secondary to ectopic adrenocorticotropic hormone (ACTH) secretion (EAS) has been described in association with a variety of tumors. The current experience with this syndrome was based on a few case series and individual case reports. Limited data were available about the tumors associated with CS-EAS in a cancer center setting. In this report, the authors have described their experience with CS-EAS at The University of Texas MD Anderson Cancer Center to further enhance the current understanding and management of this syndrome. METHODS: This was a retrospective review of 43 patients with CS-EAS who were diagnosed between 1979 and 2009 at The University of Texas MD Anderson Cancer Center. RESULTS: Different neuroendocrine tumors were associated with CS-EAS. Twenty-one patients (48.9%) had tumors located in the chest cavity, with bronchial carcinoid and small cell lung cancer representing the 2 most common causes. The ACTH source remained occult in 4 patients (9.3%) despite extensive workup. Clinical presentation varied, and the classic features of CS were not evident in some patients. Death occurred in 27 patients (62.8%), and the median overall survival was 32.2 months. Major morbidities included new-onset or worsening hyperglycemia (77%), symptomatic venous thromboembolism (14%), and infections (23%). CONCLUSIONS: In patients with CS-EAS who attended a comprehensive cancer center, tumors originating in the chest cavity were the leading tumors associated with this syndrome. The authors suspect that CS-EAS is under reported because of the atypical presentation in some patients. Thus, they suggest careful evaluation of patients with neuroendocrine tumors to avoid missing coexisting CS-EAS.
Asunto(s)
Síndrome de ACTH Ectópico/etiología , Hormona Adrenocorticotrópica/metabolismo , Síndrome de Cushing/complicaciones , Neoplasias Pulmonares/etiología , Tumores Neuroendocrinos/etiología , Carcinoma Pulmonar de Células Pequeñas/etiología , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/metabolismo , Adulto , Anciano , Carcinoma Broncogénico/diagnóstico , Carcinoma Broncogénico/etiología , Carcinoma Broncogénico/metabolismo , Comorbilidad , Femenino , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/metabolismo , Masculino , Persona de Mediana Edad , Tumores Neuroendocrinos/diagnóstico , Tumores Neuroendocrinos/metabolismo , Pronóstico , Estudios Retrospectivos , Carcinoma Pulmonar de Células Pequeñas/diagnóstico , Carcinoma Pulmonar de Células Pequeñas/metabolismo , Tasa de Supervivencia , Adulto JovenRESUMEN
Both severe hypokalemia and persistent hypertension are clinical symptoms of hyperaldosteronism. Hyperaldosteronism may occur as a primary or secondary syndrome. Excess ACTH produced ectopically by tumors may induce hyperaldosteronism through the mineralocorticoid activity of glucocorticoids that are upregulated by ACTH. Licorice, with the active ingredient glycyrrhiza, is also a well-known inducer of hyperaldosteronism under specific conditions. In this report, we describe a case of severe hypokalemia caused by ectopic ACTH syndrome (EAS) elicited by an intrathoracic carcinoid tumor, which had transformed to produce ACTH during the 6-year clinical course, and was modulated by licorice ingestion. Hypokalemia was not clearly recognized preoperatively but became obvious within 3 h of general anesthesia with epidural blockade. At the end of anesthesia, arterial blood gas analysis indicated severe hypokalemia ([K(+)] = 1.7 mEq/l) and metabolic alkalosis (pH 7.56, PaCO(2) = 54.9 mmHg, HCO(3)(-) = 44.5 mmol/l, BE = 21.8 mmol/l), without any typical symptoms such as muscle weakness or ECG abnormalities. The hypokalemia was resistant to potassium supplementation and persisted for 4 days. Perioperative imbalance between the administration and elimination of potassium and surgical stress might contribute to the rapid exacerbation and induce the clinical manifestation of EAS.
Asunto(s)
Síndrome de ACTH Ectópico/diagnóstico , Hipertensión/diagnóstico , Hipopotasemia/diagnóstico , Síndrome de ACTH Ectópico/complicaciones , Adyuvantes Anestésicos , Anestesia , Anestésicos Intravenosos , Análisis de los Gases de la Sangre , Presión Sanguínea/fisiología , Tumor Carcinoide/complicaciones , Tumor Carcinoide/cirugía , Fentanilo , Frecuencia Cardíaca/fisiología , Hormonas/sangre , Humanos , Hipertensión/complicaciones , Hipopotasemia/complicaciones , Masculino , Persona de Mediana Edad , Nicardipino , Periodo Perioperatorio , Piperidinas , Neumonía por Pneumocystis/complicaciones , Trastornos Psicóticos/etiología , Remifentanilo , Neoplasias Torácicas/complicaciones , Neoplasias Torácicas/cirugía , Tomografía Computarizada por Rayos XRESUMEN
A 91-year-old depressed woman had resistant hypertension despite a triple combination of anti-hypertensives, including a Ca-antagonist, an angiotensin receptor blocker, and a thiazide diuretic at optimal doses. She had hypokalemic metabolic alkalosis, elevated plasma cortisol and ACTH, and elevated urinary cortisol. The high-dose dexamethasone did not suppress the elevated ACTH and cortisol. The addition of spironolactone to her previous medications controlled and normalized hypertension, hypokalemia, and hormonal abnormalities within 4 months. Her blood pressure, serum electrolytes, and the hormonal states remained normalized for more than a year thereafter. Her depressed mental state also improved after spironolactone.
Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 2/fisiología , Síndrome de ACTH Ectópico/diagnóstico , Hormona Adrenocorticotrópica/metabolismo , Síndrome de Cushing/etiología , Hidrocortisona/metabolismo , Hipertensión/etiología , Receptores de Glucocorticoides/fisiología , Receptores de Mineralocorticoides/fisiología , Espironolactona/uso terapéutico , Anciano de 80 o más Años , Antihipertensivos/uso terapéutico , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/tratamiento farmacológico , Síndrome de Cushing/fisiopatología , Depresión/tratamiento farmacológico , Depresión/etiología , Depresión/fisiopatología , Dexametasona , Diagnóstico Diferencial , Resistencia a Medicamentos , Quimioterapia Combinada , Femenino , Humanos , Hipertensión/tratamiento farmacológico , Hipopotasemia/etiología , Hipopotasemia/fisiopatología , Estrés Psicológico/complicacionesRESUMEN
BACKGROUND: A 24-year-old woman presented with a 12.5 kg weight gain over 6 months (mostly abdominal), hirsutism, acne, ankle edema, polydipsia, nocturia, back pain, pigmentation, poor libido and lightened menses to our hospital in May 1986. She had been treated for the previous 2 years with furosemide and spironolactone for peripheral edema, and had stopped the combined oral contraceptive 2 months previously. She did not take tobacco, recreational drugs or alcohol. Upon physical examination she was grossly Cushingoid with florid clinical manifestations. INVESTIGATIONS: Serum potassium and bicarbonate, circadian rhythm of cortisol, low-dose and high-dose dexamethasone suppression tests, plasma adrenocorticotropic hormone (ACTH), corticotropin releasing-hormone stimulation test, CT scan of the pituitary, plain chest radiology, CT scan of the chest and abdomen, trans-sphenoidal pituitary biopsy and histology, CT scan and MRI of the thorax, MRI of the pituitary, octreotide scintigraphy, gastroscopy, colonoscopy, gut peptides, tumor markers, urine 5-hydroxyl-indole-acetic acid, resection, histology, immunocytochemistry and in situ hybridization. DIAGNOSIS: Occult ectopic ACTH syndrome from a presumed appendiceal neuroendocrine tumor. The tumor was only identified some 20 years from initial presentation. MANAGEMENT: Adrenolytic therapy before bilateral adrenalectomy to cure Cushing's syndrome, glucocorticoid and mineralocorticoid replacement therapy, and then repeated surveillance over 20 years to locate the ectopic source of ACTH. This was finally identified by CT scan and excised at laparotomy.
Asunto(s)
Síndrome de ACTH Ectópico/complicaciones , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/etiología , Adrenalectomía , Adulto , Neoplasias del Apéndice/diagnóstico , Neoplasias del Apéndice/diagnóstico por imagen , Neoplasias del Apéndice/metabolismo , Neoplasias del Apéndice/cirugía , Tumor Carcinoide/diagnóstico , Tumor Carcinoide/diagnóstico por imagen , Tumor Carcinoide/metabolismo , Tumor Carcinoide/cirugía , Femenino , Humanos , Cuidados a Largo Plazo , UltrasonografíaRESUMEN
INTRODUCTION: Endogenous Cushing's syndrome is a clinical state resulting from prolonged, inappropriate exposure to excessive endogenous secretion of cortisol and hence excess circulating free cortisol, characterized by loss of the normal feedback mechanisms of the hypothalamo-pituitary-adrenal axis and the normal circadian rhythm of cortisol secretion [2]. The etiology of Cushing's syndrome may be excessive ACTH secretion from the pituitary gland, ectopic ACTH secretion by nonpituitary tumor, or excessive autonomous secretion of cortisol from a hyperfunctioning adrenal adenoma or carcinoma. Other than this broad ACTH-dependent and ACTH-independent categories, the syndrome may be caused by ectopic CRH secretion, PPNAD, MAH, ectopic action of GIP or catecholamines, and other adrenel-dependent processes associated with adrenocortical hyperfunction. CASE REPORT: A 31 year-old men with 6-month history of hyperpigmentation, weight gain and proximal myopathy was refereed to Institute of Endocrinology for evaluation of hypercortisolism. At admission, patient had classic cushingold habit with plethoric face, dermal and muscle atrophy, abdominal strie rubrae and centripetal obesity. The standard laboratory data showed hyperglycaemia and hypokaliemia with high potassium excretion level. The circadian rhythm of cortisol secretion was blunted, with moderately elevated ACTH level, and without cortisol suppression after low-dose and high-dose dexamethason suppression test. Urinary SHIAA was elevated. Abdominal and sellar region magnetic resonance imaging was negative. CRH stimulation resulted in ACTH increase of 87% of basal, but without significant increase of cortisol level, only 7%. Thoracal CT scan revealed 14 mm mass in right apical pulmonary segment. A wedge resection of anterior segment of right upper lobe was performed. Microscopic evaluation showed tumor tissue consisting of solid areas of uniform, oval cells with eosinophilic cytoplasm and centrally located nuclei. Stromal tissue was scanty, and mitotic figures were infrequent. Tumor cells were immunoreactive for synaptophysin, neuron-specific enolase, and ACTH. The postoperative course was uneventful and the patient was discharged on glucocorticoid supplementation. Signs of Cushing's syndrome were in regression, and patient remained normotensive and normoglycaemic without therapy. DISCUSSION: A multitude of normal nonpituitary cells from different organs and tissues have been shown to express the POMC gene from which ACTH is derived. The tumors most commonly associated the ectopic ACTH syndrome arise from neuroendocrine tissues, APUD cells. POMC gene expression in non-pituitary cells differs from that in pituitary cells both qualitatively and quantitatively [8]. Aggressive tumors, like small cell cancer of the lung (SCCL) preferentially release intact POMC, whereas carcinoids rather overprocess the precursor, releasing ACTH and smaller peptides like CLIP. Some tumors associated with ectopic ACTH syndrome express other markers of neuroendocrine differentiation like two specific prohormone convertases (PCs). Assessment of vasopressin (V3) receptor gene expression in ACTH-producing nonpitultary tumors revealed bronchial carcinoid as a particular subset of tumors where both V3 receptor and POMC gene may be expressed in pattern indistinguishable from that in corticotroph adenoma [9]. In most, but not all, patients with ectopic ACTH syndrome, cortisol is unresponsive to high-dose dexamethason suppression test, what is used as diagnostic tool. It is not clear if the primary resistance resulted from structural abnormality of the native glucocorticoid receptor (GR), a low level of expression, or some intrinsic property of the cell line [9]. It appears that ectopic ACTH syndrome is made of two different entities. When it is because of highly differentiated tumors, with highest level of pituitary-like POMC mRNA, expressing PCs, high level of V3 receptors and GR, like bronchial carcinoids, it might be called ectopic corticotroph syndrome. In contrast, when it is caused by aggressive, poorly differentiated tumors, with much lower expression of V3 receptor, like SCCL, it might be called aberrant ACTH secretion syndrome. Carcinoid tumors have been reported in a wide range of organs but most commonly involve the lungs, bronchi, and gastrointestinal tract. They arise from neuroendocrine cells and are characterized by positive reactions to markers of neuroendocrine tissue, including neuron specific enolase, synaptophysin, and chromogranina [11]. Carcinoid tumors are typically found to contain numerous membrane-bound neurosecretory granules composed of variety of hormones and biogenic amines. One of the best characterized is serotonin, subsequently metabolized to 5-hydrohy-indolacetic acid (5-HIAA), which is excreted in the urine. In addition to serotonin, carcinoid tumors have been found to secrete ACTH, histamine, dopamine, substance P, neurotensin, prostaglandins and kallikrein. The release of serotonin and other vasoactive substances is thought to cause carcinoid syndrome, which manifestations are episodic flushing, weezing, diarrhea, and eventual right-sided valvular heart disease. These tumors have been classified as either well-differentiated or poorly differentiated neuroendocrine carcinomas. The term "pulmonary tumorlets" describes multiple microscopic nests of neuroendocrine cells in the lungs [12]. Pulmonary carcinoids make up approximately 2 percents of primary lung tumors. The majority of these tumors are perihilar in location, and patients often presents with recurrent pneumonia, cough, hemoptisis, or chest pain. The carcinoid syndrome occurs in less than 5 percent of cases. Ectopic secretion of ACTH from pulmonary carcinoid accounts for 1 percent of all cases of Cushing's syndrome. They are distinct clinical and pathologic entity, generally peripheral in location. Although they are usually typical by standard histologic criteria, they have mush greater metastatic potential than hormonally quiescent typical carcinoids [13]. Surgical treatment therefore should be one proposed for more aggressive malignant tumors. In all cases of ACTH-dependent Cushing's syndrome with regular pituitary MRI and bilateral inferior petrosal sinus sampling, thin-section and spiral CT scanning of the chest should be routine diagnostic procedure [14]. We present thirty-one year old patient with typical pulmonary carcinod with ACTH ectopic secretion consequently confirmed by histology.
Asunto(s)
Síndrome de ACTH Ectópico/diagnóstico , Tumor Carcinoide/metabolismo , Neoplasias Pulmonares/metabolismo , Adulto , Tumor Carcinoide/diagnóstico , Humanos , Neoplasias Pulmonares/diagnóstico , MasculinoRESUMEN
Ectopic adrenocorticotropic hormone (ACTH) and/or corticotropin-releasing hormone (CRH) are associated with a growing list of tumors. We report a 69-year-old white man with a history of high-grade prostate carcinoma and widely metastatic adenocarcinoma who presented with metabolic alkalosis, hypokalemia, and hypertension secondary to ectopic ACTH and CRH secretion. Laboratory values were consistent with hypokalemia and metabolic alkalosis. Markedly elevated serum cortisol (135 microg/dL), ACTH (1,387 pg/dL), CRH (69 pg/dL), and urine free cortisol (16,276 microg/24 h) levels were found. Chest computed tomographic (CT) scan showed small noncalcified parenchymal densities; however, bronchoscopy and bronchoalveolar lavage washings were unremarkable for a neoplastic process. Abdominal CT scan and magnetic resonance imaging showed multiple small liver lesions and multiple thoracic and lumbar intensities consistent with diffuse metastatic disease. Histological analysis of a biopsy specimen from the thoracic spine showed an undifferentiated adenocarcinoma consistent with a prostate primary tumor. The severe metabolic alkalosis secondary to glucocorticoid-induced excessive mineralocorticoid activity was treated with potassium supplements, spironolactone, and ketoconazole. In this case report, we describe an unusual tumor associated with ectopic ACTH and CRH production and the pharmacodynamic relationship of plasma cortisol levels and urinary cortisol excretion with ketoconazole treatment.
Asunto(s)
Adenocarcinoma/secundario , Alcalosis/diagnóstico , Síndrome de Cushing/diagnóstico , Hipertensión/diagnóstico , Hipopotasemia/diagnóstico , Neoplasias de la Próstata/secundario , Síndrome de ACTH Ectópico/diagnóstico , Síndrome de ACTH Ectópico/tratamiento farmacológico , Síndrome de ACTH Ectópico/epidemiología , Adenocarcinoma/diagnóstico , Hormona Adrenocorticotrópica/sangre , Anciano , Alcalosis/epidemiología , Comorbilidad , Hormona Liberadora de Corticotropina/sangre , Hormona Liberadora de Corticotropina/metabolismo , Síndrome de Cushing/epidemiología , Humanos , Hidrocortisona/sangre , Hipertensión/epidemiología , Hipopotasemia/epidemiología , Cetoconazol/uso terapéutico , Masculino , Metástasis de la Neoplasia/diagnóstico , Síndromes Paraneoplásicos Endocrinos/diagnóstico , Síndromes Paraneoplásicos Endocrinos/epidemiología , Neoplasias de la Próstata/diagnóstico , Tomografía Computarizada por Rayos XRESUMEN
The efficiency of various laboratory and radiological investigations in the differentiation of ectopic from pituitary dependent Cushing's syndrome was studied, based on findings in 23 patients with verified Cushing's disease and seven patients with the ectopic ACTH syndrome. Clinical features strongly favouring the ectopic type were male sex and history for less than 18 months. Basal biochemical features strongly indicating the ectopic syndrome included plasma K+ less than 3.0 mmol/l and HCO3 greater than 30 mmol/l; serum cortisol at 9 a.m. or midnight of greater than 800 nmol/l; urine free cortisol greater than 1300 nmol/24 hours; plasma ACTH greater than 100 ng/l. In the high-dose dexamethasone suppression test, suppression by less than 50 per cent of 9 a.m. serum cortisol, urine free cortisol or 17-oxogenic steroids was usually indicative of an ectopic source of ACTH. A mean suppressed value of greater than 450 nmol/l for the 9 a.m. and midnight cortisol combined occurred in all of those with the ectopic syndrome, but in none of the 23 patients with Cushing's disease. For urine free cortisol, a mean suppressed value of less than 1000 nmol/24 hours was found in all patients with Cushing's disease, but in none of those in the ectopic group. In the metyrapone test, there was an increase of less than or equal to 3-fold in 11-deoxycortisol at 24 hours in patients with ectopic ACTH; the increase was greater than 3-fold in all but one of the patients with Cushing's disease. Failure to respond to either dexamethasone or metyrapone was found in only one of the patients with Cushing's disease (Patient 16); in the ectopic group, all patients except Patient D failed to respond to either test. It is concluded that patients presenting with clinically obvious Cushing's syndrome along with measurable plasma ACTH can be reliably divided by conventional tests into those that are driven from the pituitary and those driven by ectopic ACTH.
Asunto(s)
Síndrome de ACTH Ectópico/diagnóstico , Hormona Adrenocorticotrópica/metabolismo , Síndrome de Cushing/diagnóstico , Hipófisis/fisiopatología , Síndrome de ACTH Ectópico/sangre , Síndrome de ACTH Ectópico/fisiopatología , Adolescente , Adulto , Síndrome de Cushing/sangre , Síndrome de Cushing/fisiopatología , Dexametasona , Diagnóstico Diferencial , Femenino , Humanos , Hidrocortisona/sangre , Metirapona , Persona de Mediana Edad , Potasio/sangreRESUMEN
The clinical features, diagnosis and management of 16 consecutive patients with ectopic ACTH production are described and biochemical data are compared with those of 48 consecutive patients with pituitary-dependent Cushing's disease. In 10 cases the ectopic ACTH secreting tumour was completely occult to routine clinical and radiological investigation, and no basal or dynamic investigation of adrenal-pituitary function was able clearly to differentiate these patients from those with Cushing's disease. High dose dexamethasone suppression testing assessed by plasma cortisol was usually helpful but unexpected responses were seen in both diagnostic groups; the metyrapone test yielded no useful information and should now be abandoned. Hypokalaemia was seen in all patients with ectopic ACTH production but in only 10% of those with Cushing's disease who were not on diuretics at presentation. Successful diagnosis and tumour localization was most frequently achieved by a combination of CT scanning of the chest and abdomen and venous catheter sampling for ACTH. All patients in whom the ectopic ACTH-secreting tumour was obvious at presentation died of their primary tumour within 8 months, whereas seven of the 10 patients with occult tumours at presentation are alive 1.5-16.5 years later, and appear cured. Occult ectopic ACTH secretion may be impossible to distinguish from pituitary Cushing's disease. Multiple and repeated investigations are often required to make this differential diagnosis, essential for appropriate therapy.