Cushing's syndrome due to ectopic adrenocorticotropin secretion by a parotid carcinoma

SUMMARY We report a rare case of Cushing's syndrome in a 37-year-old female who initially presented with localized acinic cell carcinoma of the parotid gland. In January 2014, she underwent a right parotidectomy with facial nerve preservation and adjuvant radiotherapy. In August 2018, she presented a histologically-proven local regional relapse. The patient was considered for salvage surgery with facial nerve sacrifice and remained with no evidence of disease. One year later the patient developed pulmonary dissemination and started to gain weight and developed facial plethora and acne on the face and upper trunk. In a physical examination, the patient presented moon face, buffalo hump, acne and stage 2 hypertension. Biochemical evaluation confirmed ACTH-dependent Cushing's syndrome. IHC for ACTH in the lung biopsy revealed strong positive staining for ACTH confirming a diagnosis of ectopic ACTH secretion by a metastatic parotid acinic cell carcinoma. Ketoconazole (600 mg/d) was started to treat the CS. In addition, as chemotherapy was initiated to treat the metastatic disease. After the fifth cycle of chemotherapy, ketoconazole was suspended and the patient remained in remission of CS for four months, when CS recurred. A unique feature of this case is related to the clinical CS relapse associated with disease progression, which needed prompt treatment with ketoconazole, resulting in a significant improvement in the patient's condition. Although rare, should be attentive for possible CS features in patients with high-grade salivary gland carcinomas, since the diagnosis of ectopic secretion of ACTH may significantly impact their management and outcomes.

The 4Ds of ectopic ACTH syndrome: diagnostic dilemmas of a difficult disease

SUMMARY Cushing's syndrome (CS) is an uncommon condition that leads to high morbidity and mortality. The majority of endogenous CS is caused by excessive ACTH secretion, mainly due to a pituitary tumor - the so-called Cushing's disease (CD) - followed by ectopic ACTH syndrome (EAS), an extra-pituitary tumor that produces ACTH; adrenal causes of CS are even rarer. Several methods are used to differentiate the two main etiologies: specific laboratory tests and imaging procedures, and bilateral inferior petrosal sinus sampling (BIPSS) for ACTH determination; however, identification of the source of ACTH overproduction is often a challenge. We report the case of a 28-year-old woman with clinical and laboratory findings consistent with ACTH-dependent CS. All tests were mostly definite, but several confounding factors provoked an extended delay in identifying the origin of ACTH secretion, prompting a worsening of her clinical condition, with difficulty controlling hyperglycemia, hypokalemia, and hypertension. During this period, clinical treatment was decisive, and measurement of morning salivary cortisol was a differential for monitoring cortisol levels. This report shows that clinical reasoning, experience and use of recent methods of nuclear medicine were decisive for the elucidation of the case.

Secreción ectópica de ACTH en un paciente con antecedentes de enfermedad de Cushing / ACTH's ectopic secretion in a patient with precedents of Cushing's disease

Hombre de 54 años con antecedentes de enfermedad de Cushing 32 años antes de la consulta. Ingresó por edemas asociados a astenia y adinamia. En el laboratorio se constató hipopotasemia y alcalosis metabólica. Se realizó diagnóstico humoral de síndrome de Cushing secundario a secreción ectópica de hormona adrenocorticotropa (ACTH). En la tomografía de tórax se halló un tumor de 3 × 3 cm en el mediastino anterior. La anatomía patológica de la pieza quirúrgica fue compatible con un carcinoide tímico. Este paciente sufrió en dos oportunidades un síndrome de Cushing, la primera por enfermedad (adenoma hipofisiario) y la segunda vez por secreción ectópica de ACTH (SEA) una asociación no descripta, en nuestro conocimiento, en la literatura médica.

A 54-year-old man, with a history of Cushing’s disease diagnosed 32 years earlier, presented with edema, asthenia and general malaise. Abnormal laboratory studies depicted hypokalemia and metabolic alkalosis. A CT scan of the chest revealed a 3 × 3 cm tumor in the anterior mediastinum. The pathology was consistent with a thymic carcinoid. These findings led to a diagnosis of biochemical Cushing’s syndrome secondary to ectopic secretion of ACTH. Thus, this patient suffered twice of Cushing’s syndrome. The first instance was the consequence of an ACTH - secreting pituitary adenoma and the second of an ectopic secretion of ACTH. To the best of our knowledge this is the first such case reported in the medical literature.

Aspectos técnicos e funcionais da cateterização dos seios petrosos inferiores na síndrome de Cushing ACTH dependente / Technical and functional aspects of catheterization of inferior petrosal sinuses in ACTH dependent Cushing’s syndrome

Objetivo Descrever e analisar a técnica empregada para a cateterização bilateral dos seios petrosos inferiores (SPI) em nosso serviço, discutindo as dificuldades e as taxas de sucesso encontradas. Sujeitos e métodos Entre 2009 e 2012, foram submetidos ao cateterismo bilateral dos SPI 14 pacientes com suspeita de síndrome de Cushing, sendo descrita a técnica empregada para o cateterismo e para a análise hormonal. Resultados O procedimento foi bem tolerado por todos os pacientes, sendo alcançada a cateterização adequada dos SPI em 92,85% dos casos. O diagnóstico de doença de Cushing foi firmado em 10 casos, sendo o resultado do cateterismo dos SPI após estímulo com CRH coerente em todos, não havendo falso-negativos. Conclusão O cateterismo dos SPI, apesar de ser uma técnica invasiva, é um procedimento seguro. A sua realização pode ser feita de forma adequada na maioria dos casos e, quando bem indicada, permanece como padrão-ouro na distinção da forma hipofisária da ectópica na síndrome de Cushing. .

Objective To describe and analyze technique for bilateral catheterization of inferior petrosal sinus in our service, discussing the difficulties and success rates found. Subjects and methods Fourteen patients with suspected Cushing’s syndrome underwent bilateral inferior petrosal sinuses (IPS) catheterization between 2009 and 2012. The technique for catheterization and for hormone analysis were described. Results The procedure was well tolerated by all patients, and adequate catheterization was achieved in 92.85% of cases. The diagnosis of Cushing’s disease was confirmed in 10 cases. The result of IPS catheterization after CRH infusion was coherent in all cases, without false negatives. Conclusion The catheterization of IPS, despite being an invasive technique, is a safe procedure. The objectives can be done properly in most cases. When well indicated, this procedure remains the gold standard in distinguishing the ectopic form to pituitary source in Cushing’s syndrome. .

Síndrome de Cushing secundario a secreción ectópica: un desafío diagnóstico / Cushing syndrome secondary to ectopic: diagnostic challenge

The diagnosis of Cushing Syndrome secondary to Ectopic ACTH secretion constitutes a challenge to the endocrinologist. The goal is to make a differential diagnosis of Cushing’s disease and localize the ACTH-secreting tumor, to achieve quick and effective management of a disease that can be fatal. The mainly diffuculties are the limited data due to their low prevalence and the wide variety of the origin tumors. Therefore, a comprehensive and multidisciplinary study is needed, analyzing each particular case. This article reviews the diagnostic alternatives, their strengths and weaknesses, proposing an algorithm that contributes to our clinical practice...

A rare case of Cushing syndrome by cyclic ectopic-ACTH / Um caso raro de síndrome de Cushing associada a ACTH-ectópico cíclico

ACTH-dependent Cushing syndrome (CS) due to ectopic ACTH production is most times difficult to manage. The identification of the source of ACTH may take many years. Surgery or chemotherapy for the primary tumor is not always possible. Control of Cushing symptoms is many times achieved using medication, or bilateral adrenalectomy in refractory cases. This case presents a Brazilian male who showed severe hypertension, mood changes, muscle weakness, darkening of skin, and increased abdominal fat. An investigation for Cushing syndrome was carried out and, after a four-year follow-up, a carotid glomus tumor (chemodectoma) was confirmed, a rare ectopic ACTH-producing tumor. Besides, the patient presented cyclic Cushing syndrome that was exacerbated by diverticulitis episodes. This case presents interesting pitfalls on diagnosis and management of ACTH-dependent CS. This is the only report of a chemodectoma that produced ACTH in the literature.

A síndrome de Cushing ACTH-dependente causada por produção ectópica de ACTH é, muitas vezes, difícil de diagnosticar e conduzir. A identificação da fonte produtora de ACTH pode demorar muitos anos. A cirurgia ou quimioterapia para o tumor primário nem sempre é possível, sendo o controle do hipercortisolismo alcançado com uso de fármacos ou adrenalectomia bilateral, nos casos refratários. Este caso apresenta um homem com hipertensão grave, mudança de humor, fraqueza proximal, escurecimento da pele e aumento de gordura abdominal. A investigação para síndrome de Cushing foi feita e, após quatro anos de acompanhamento, confirmou-se um tumor de glomus carotídeo (quemodectoma), causa rara de tumor secretor de ACTH. Nesse período, o paciente apresentou síndrome de Cushing cíclica, exacerbada por crises de diverticulite. O caso ilustra pontos importantes no diagnóstico, no acompanhamento e na condução da síndrome de Cushing ACTH-dependente, sendo este o único caso de tumor de glomus de carótida produzindo ACTH descrito na literatura médica.

Severe hypertension and hypokalemia as first clinical manifestations in ectopic Cushing's syndrome / Hipertensão grave e hipocalemia como primeiras manifestações clínicas em casos de síndrome de Cushing ectópica

Ectopic ACTH production occurs in about 10 percent of all cases of Cushing's syndrome, and about 25 percent of cases of ACTH-dependent Cushing's syndrome. Diverse tumor types are able to produce ACTH ectopically, including small cell lung carcinoma. Ectopic ACTH secretion by malignant neoplasm has been reported to have earlier and more aggressive metabolic effects. We report a 59-year-old male patient with severe hypertension, metabolic alkalosis and hypokalemia as the first clinical manifestations of an ACTH-secreting small cell lung carcinoma, although the typical phenotypic features of Cushing's syndrome were not present. Ectopic Cushing's syndrome should always be ruled out in patients with severe hypertension and hypokalemia.

A produção de ACTH ectópico ocorre em aproximadamente 10 por cento dos casos de síndrome de Cushing, e em aproximadamente 25 por cento dos casos de síndrome de Cushing dependentes de ACTH. Diversos tipos de tumores são capazes de produzir ACTH ectopicamente, incluindo carcinoma pulmonar de células pequenas. Relatórios indicam que a secreção de ACTH ectópico por neoplasma maligno causa efeitos metabólicos prematuros e mais agressivos. Apresentamos um paciente, 59 anos, com hipertensão grave, alcalose metabólica e hipocalemia, tendo estas como as primeiras manifestações clínicas de um carcinoma pulmonar de células pequenas com secreção de ACTH, embora as características fenótipas típicas da síndrome de Cushing não estavam presentes. A síndrome de Cushing ectópica deveria ser excluída sempre em pacientes com hipertensão grave e hipocalemia.

Cateterização dos seios petrosos inferiores: aspectos técnicos / Inferior petrosal sinus catheterization: technical aspects

OBJETIVO: O cateterismo dos seios petrosos inferiores (SPI) ajuda a diferenciar as formas hipofisária e ectópica na síndrome de Cushing (SC). O objetivo desse trabalho é descrever a técnica empregada em nosso serviço, discutir a solução de dificuldades e verificar o índice de sucesso atingido. CASUÍSTICA E MÉTODO: Foram submetidos a cateterismo bilateral dos SPI 42 pacientes com SC, entre setembro de 2000 e setembro de 2005. As dificuldades para o posicionamento do cateter foram correlacionadas com as soluções empregadas. RESULTADOS: As variações anatômicas, a semelhança entre o SPI e a veia emissária do plexo basilar e a dificuldade de contrastar as estruturas a contrafluxo para localizá-las foram os principais problemas. Foram utilizados cateter pré-moldado, fio-guia semicurvo e dirigível, road-maping e venografia por injeção contralateral, além de critérios para diferenciar o SPI da veia emissária. Dos 84 SPI abordados, um apresentava trombose, e dos 83 possíveis, 80 (96,4 por cento) foram cateterizados. Não se observaram complicações. CONCLUSÃO: A cateterização dos SPI pode ser feita na maioria dos pacientes. A identificação da veia emissária do plexo basilar e o uso de flebografia por injeção contralateral melhoraram o desempenho do método.

PURPOSE: Inferior petrosal sinus catheterization and sampling for corticotropin dosage helps to differentiate hypophisary and ectopic forms of Cushing syndrome. The aim of this paper is to describe the technique used in inferior petrosal sinus catheterization in our service, emphasizing the solution found for frequent difficulties, and verify the success rate achieved. PATIENTS AND METHODS: Between September/2000 and September/2005, forty-two (eighty-four sinuses) patients were submitted to inferior petrosal sinus sampling. The difficulties for correct catheter positioning were identified and correlated with their solutions. RESULTS: Anatomical variations, similarity between IPS and emissary vein of the basilar plexus and unfavorable flow to the contrastation of the structures (retrograde catheterization) were the main problems. Using pre-shaped catheters, curved, steerable guide-wires, road-maping and venography by contalateral injection, besides criteria to differentiate IPS from the emissary vein. Of the 84 sinuses approached, one was thrombosed, and 80 (96.4 percent) of 83 possible were selectively catheterized. No clinical complication occurred. CONCLUSION: IPSC can be safe and successfully performed in most cases. The identification of the emissary vein of the basilar plexus and use of venography by contralateral injection, improved the method performance.

Report pf bilateral inferior petrosal sinus sampling in Iran

The differential diagnosis of ACTH-dependent Cushing syndrome is a challenging issue for clinical endocrinologists. MRI is commonly used to diagnose Cushing disease and remains the obvious technique to identify pituitary microadenomas in a noninvasive manner but it has proved to be problematic in some cases

Pitfalls in the diagnosis of Cushing's syndrome: [review]

Among endocrine disorders, Cushing's syndrome (CS) is certainly one of the most challenging to endocrinologists due to the difficulties that often appear during investigation. The diagnosis of CS involves two steps: confirmation of hypercortisolism and determination of its etiology. Biochemical confirmation of the hypercortisolaemic state must be established before any attempt at differential diagnosis. Failure to do so will result in misdiagnosis, inappropriate treatment, and poor management. It should also be kept in mind that hypercortisolism may occur in some patients with depression, alcoholism, anorexia nervosa, generalized resistance to glucocorticoids, and in late pregnancy. Moreover, exogenous or iatrogenic hypercortisolism should always be excluded. The three most useful tests to confirm hypercortisolism are the measurement of 24-h urinary free cortisol levels, low-dose dexamethasone-suppression tests, and determination of midnight serum cortisol or late-night salivary cortisol. However, none of these tests is perfect, each one has different sensitivities and specificities, and several are usually needed to provide a better diagnostic accuracy. The greatest challenge in the investigation of CS involves the differentiation between Cushing's disease and ectopic ACTH syndrome. This task requires the measurement of plasma ACTH levels, non-invasive dynamic tests (high-dose dexamethasone suppression test and stimulation tests with CRH or desmopressin), and imaging studies. None of these tests had 100 percent specificity and their use in combination is usually necessary. Bilateral inferior petrosal sinus sampling is mainly indicated when non-invasive tests do not allow a diagnostic definition. In the present paper, the most important pitfalls in the investigation of CS are reviewed.

Entre as doenças endócrinas, a síndrome de Cushing (SC) é certamente uma das mais desafiadoras para o endocrinologista, devido às dificuldades que comumente surgem durante a investigação. O diagnóstico de SC envolve dois passos: a confirmação do hipercortisolismo e a determinação de sua etiologia. A confirmação bioquímica do excesso de cortisol precisa ser estabelecida antes de qualquer tentativa de diagnóstico diferencial; caso contrário, poderá resultar em diagnóstico incorreto, tratamento impróprio e manejo insuficiente. Deve também ser lembrado que hipercortisolismo pode ocorrer em certos pacientes com depressão, alcoolismo, anorexia nervosa, resistência generalizada aos glicocorticóides e no final da gravidez. Além disso, hipercortisolismo exógeno ou iatrogênico deverá ser sempre excluído. Os três testes mais úteis para a confirmação do hipercortisolismo são: a medida do cortisol livre em urina de 24 h, os testes de supressão com dexametasona (TSD) em doses baixas e a determinação do cortisol sérico à meia-noite ou do cortisol salivar no final da noite. Contudo, nenhum deles é perfeito, cada um com sua sensibilidade e especificidade, sendo vários deles usualmente necessários para fornecer uma melhor acurácia diagnóstica. O maior desafio na investigação da SC envolve a diferenciação entre a doença de Cushing e a síndrome do ACTH ectópico. Esta tarefa requer a medida dos níveis plasmáticos de ACTH, testes dinâmicos não-invasivos (TSD com doses altas e testes de estímulo com CRH ou desmopressina) e estudos de imagem. Nenhum desses testes tem 100 por cento de especificidade e muitas vezes é necessário seu uso combinado. Amostragem venosa do seio petroso inferior está indicada principalmente quando os testes não-invasivos não permitem uma definição diagnóstica. Neste artigo, revisaremos as mais importantes armadilhas na investigação da SC.

Ectopic ACTH syndrome

Ectopic adrenocorticotropic secretion (EAS) is responsible for 12-17 percent of cases of Cushing's syndrome (CS) and covers a range of tumours, from undetectable benign lesions to widespread metastases. The syndrome is often associated with severe hypercortisolaemia, which aggravates the underlying condition. EAS requires a complete workup that includes the establishment of endogenous CS, diagnosis of adrenocorticotropic hormone (ACTH) dependency, localization of the source of ACTH secretion and rapid biochemical control of hypercortisolaemia. Dynamic endocrine tests should include inferior petrosal sinus sampling with CRH stimulation. Localization studies depend on the availability of reliable high-resolution cross-sectional imaging. This systematic review of the largest published series of patients with EAS (over 380 patients) reveals the common trends in the prevalence and management of this syndrome. The concept of 'occult' EAS has been revisited and the terms 'overt' and 'covert' EAS introduced. In addition to small cell lung carcinoma, the most common causes of ectopic EAS are bronchial carcinoids, thymic tumours, islet cell tumour of the pancreas, medullary thyroid carcinomas, and phaeochromocytomas. Their prevalence and the best localization modalities are presented. Medical and surgical management is discussed on the basis of the extensive experience of major referral centres.

A secreção ectópica de ACTH (SEA) é responsável por 12-17 por cento dos casos de síndrome de Cushing (SC), cobrindo uma variedade de tumores, desde lesões benignas indetectáveis a metástases disseminadas. A SEA está freqüentemente associada com hipercortisolemia grave, que agrava a condição de base e requer uma avaliação completa, que inclui a confirmação da SC endógena, o diagnóstico da dependência ao ACTH, a localização da fonte da secreção de ACTH e o controle bioquímico rápido da hipercortisolemia. Testes endócrinos dinâmicos devem incluir a coleta de amostras do seio petroso inferior com estímulo pelo CRH. O estudo da localização da fonte depende da disponibilidade de procedimentos de imagem de alta-resolução confiáveis. A revisão sistemática das maiores séries publicadas de pacientes com SEA (mais de 380 pacientes) revela tendências comuns na prevalência e manejo dessa síndrome. O conceito de SEA "oculta" está sendo revisado e os termos SEA "manifesta" e "latente" são introduzidos. Além do carcinoma pulmonar de pequenas células, as causas mais comuns de SEA são os carcinóides brônquicos, tumores tímicos, tumor de ilhotas pancreáticas, carcinoma medular de tiróide e feocromocitoma; sua prevalência e as melhores modalidades para localização são apresentadas. O manejo clínico e cirúrgico é discutido com base na vasta experiência dos principais centros de referência.

Imaging in Cushing's syndrome: [review]

Once the diagnosis of Cushing's syndrome (CS) has been established, the main step is to differentiate between ACTH dependent and independent disease. In adults, 80 percent of CS is due to ACTH-dependent causes and 20 percent due to adrenal causes. ACTH-secreting neoplasms cause ACTH-dependent CS. These are usually anterior pituitary microadenomas, which result in the classic Cushing's disease. Non-pituitary ectopic sources of ACTH, such as a small-cell lung carcinoma or carcinoid tumours, are the source of the remainder of ACTH-dependent disease. In the majority of patients presenting with clinical and biochemical evidence of CS, modern non-invasive imaging can accurately and efficiently provide the cause and the nature of the underlying pathology. Imaging is essential for determining the source of ACTH in ectopic ACTH production, locating the pituitary tumours and distinguishing adrenal adenomas, carcinomas and hyperplasias. In our chapter we review the adrenal appearances in ACTH-dependent and ACTH-independent CS. We also include a discussion on the use of MRI and CT for the detection and management of pituitary ACTH secreting adenomas. CT of the chest, abdomen and pelvis with intravenous injection of contrast medium is the most sensitive imaging modality for the identification of the ectopic ACTH source and detecting adrenal pathology. MRI is used for characterising adrenal adenomas, problem solving in difficult cases and for detecting ACTH-secreting pituitary adenomas.

Uma vez estabelecido o diagnóstico da síndrome de Cushing (SC), o passo principal é diferenciar entre a doença ACTH-dependente e a independente. Em adultos, 80 por cento da SC é devida a causas ACTH-dependentes e 20 por cento a causas adrenais. Neoplasias secretoras de ACTH causam a SC ACTH-dependente: usualmente são microadenomas da hipófise anterior que resultam na clássica doença de Cushing. Fontes ectópicas (não hipofisárias) de ACTH, como o carcinoma pulmonar de células pequenas e tumores carcinóides, são a origem do restante da doença ACTH-dependente. Na maioria dos pacientes que se apresentam com evidências clínicas e bioquímicas da SC, técnicas modernas de imagem não invasivas podem apontar acurada e eficientemente a causa e a natureza da patologia subjacente. A imagem é essencial para a determinação da fonte de ACTH na produção ectópica desse hormônio, na localização de tumores hipofisários e na distinção entre adenomas, carcinomas e hiperplasias adrenais. Nesse artigo revisaremos a imagem adrenal na SC ACTH-dependente e independente. Incluiremos, também, uma discussão sobre o uso da RM e da TC na detecção e manejo dos adenomas hipofisários secretores de ACTH. TC de tórax, abdome e pelve, com a injeção intravenosa de meio de contraste, é a modalidade de imagem mais sensível para a identificação da fonte ectópica de ACTH e na detecção da patologia adrenal. A RM é empregada para a caracterização de adenomas adrenais, para a solução de problemas em casos difíceis e para a detecção de adenomas hipofisários secretores de ACTH.

The role of bilateral inferior petrosal sinus sampling in the diagnosis of Cushing's syndrome

Adrenocorticotropin hormone (ACTH)-dependent Cushing's syndrome is most often due to a pituitary corticotroph adenoma, with ectopic ACTH-secreting tumors representing approximately 15 percent of cases. Biochemical and radiological techniques have been established to help distinguish between these two entities, and thus aid in the localization of the neoplastic lesion for surgical resection. The test that offers the highest sensitivity and specificity is bilateral inferior petrosal sinus sampling (BIPSS). BIPSS is an interventional radiology procedure in which ACTH levels obtained from venous drainage very near the pituitary gland are compared to peripheral blood levels before and after corticotropin hormone (CRH) stimulation. A gradient between these two locations indicates pituitary Cushing's, whereas the absence of a gradient suggests ectopic Cushing's. Accurate BIPSS results require hypercortisolemia to suppress normal corticotroph ACTH production and hypercortisolemia at the time of the BIPSS to assure excessive ACTH secretion. In some cases, intrapituitary gradients from side-to-side can be helpful to localize small corticotroph adenomas within the sella. BIPSS has rare complications and is considered safe when performed at centers with experience in this specialized technique.

A síndrome de Cushing (SC) ACTH-dependente é mais freqüentemente devida a um adenoma corticotrófico da hipófise, com os tumores ectópicos secretores de ACTH representando aproximadamente 15 por cento dos casos. Técnicas bioquímicas e radiológicas foram estabelecidas para permitir a distinção entre essas duas entidades e, assim, auxiliar na localização da lesão neoplásica para ressecção cirúrgica. O teste que oferece a mais alta sensibilidade e especificidade é a coleta bilateral de amostras de sangue do seio petroso inferior (BIPSS). BIPSS é um procedimento de intervenção radiológica no qual os níveis de ACTH obtidos da drenagem venosa bem próxima da hipófise são comparados com os níveis sanguíneos periféricos antes e após estímulo com corticorrelina (CRH). Um gradiente entre essas duas localizações indica SC hipofisário, enquanto a ausência de gradiente sugere SC ectópica. Resultados acurados na BIPSS requerem a presença de hipercortisolemia e que ela suprima normalmente a produção de ACTH pelo corticotrofos por ocasião da BIPSS para garantir a secreção excessiva de ACTH. Em alguns casos, os gradientes intra-hipofisários de um lado para outro podem ser úteis na localização de pequenos adenomas corticotróficos no interior da sela. A BIPSS raramente apresenta complicações, sendo considerada segura quando realizada em centros com experiência nessa técnica especializada.

El cateterismo bilateral y simult neo de los senos petrosos inferiores en el diagnóstico diferencial del síndrome de Cushing / Bilateral inferior petrosal sinus sampling in the differential diagnosis of ACTH-dependent Cushing's syndrome

Background: The features of pituitary ACTH-dependent Cushing syndrome are often indistinguishable from those of occult ectopic ACTH-dependent Cushing syndrome (CS). Aim: To assess the diagnostic accuracy of bilateral inferior petrosal sinus sampling (BIPSS) in the differential diagnosis of ACTH-dependent Cushing's syndrome as compared with ACTH levels and the overnight high dose dexamethasone suppression test (HDDST). Material and methods: Retrospective review of medical records of 23 patients (aged 19 to 63 years, 16 women) with surgically proven CS, 20 pituitarymicroadenomas (CD) and 3 with occult ectopic ACTH secretion (EAS). Results: No tumor was identifiable by imaging techniques. Mean plasma ACTH values were higher in patients with EAS than in CD (103± 110.2 and 73.1±41.98 pg/mL respectively, p=NS). Three patients with EAS and 3 patients with CD did not suppress cortisol with the HDDST. The sensitivity of the test was 86 percent and the specificity 100 percent. To improve the diagnostic outcome of BIPSS, an stimulation with Desmopressin (9 fig i.v) was performed in 9 patients. The threshold for a pituitary source, was defined as an inferior petrosal sinus to peripheral ACTH basal and post Desmopression ratio >2. BIPSS was successfully carried out in 22 patients and no complications occurred. In 6 patients BIPSS failed to meet the threshold criteria. In 3 patients, bronchial carcinoid tumors which proved to synthesize ACTH, were removed. The diagnostic sensitivity of BIPSS greatly improved from 86 percent to 100 percent after Desmopressin stimulation. BIPSS accurately predicted the ¡ateralization of the microadenoma in 8 of 12 patients (66 percent). Conclusions: The combination of Desmopressin stimulation with BIPSS was useful for the differential diagnosis of ACTH-dependent Cushing's Syndrome. However, the preoperative location of pituitary microadenomas was poorly predicted by BIPSS.

Síndrome de cushing endógena: características clínico-laboratoriais em 73 casos / Endogenous cushings syndrome: clinical and laboratorial features in 73 cases

Avaliamos as características clínico-laboratoriais de 73 pacientes com síndrome de Cushing (SC) endógena, assim distribuídos: 46 (63 por cento) com doença de Cushing (DC), 21 (28,7 por cento) com tumores adrenais (TA) e 6 (8,2 por cento) com a síndrome do ACTH ectópico (SAE). A freqüência de manifestações clássicas do hipercortisolismo foi similar, independentemente da etiologia da SC. Em 100 por cento dos casos de SC, observaram-se níveis do cortisol sérico (CS) > 1,8 µg/dL após supressão com doses baixas de dexametasona (DMS), além de elevação do cortisol à meia-noite (sérico ou salivar). Contudo, o cortisol livre urinário foi normal em 11,5 por cento dos pacientes. Os níveis de ACTH mostraram-se suprimidos nos pacientes com TA, normais ou elevados na DC e sempre elevados na SAE. No teste de supressão noturna com 8 mg de DMS, supressão do CS > 50 por cento foi observada em 78,2 por cento dos casos de DC e 33,3 por cento dos casos de SAE, enquanto uma supressão > 80 por cento foi exclusiva da DC. Após estímulo com CRH ou DDAVP, um incremento do ACTH > 35 por cento aconteceu em 81 por cento dos indivíduos com DC e em 16,6 por cento daqueles com SAE, ao passo que um incremento do ACTH > 50 por cento restringiu-se à DC. A combinação de incremento do ACTH > 35 e supressão do CS > 50 por cento foi também exclusiva da DC. A ressonância magnética visualizou 100 por cento dos macroadenomas e 59,4 por cento dos microadenomas hipofisários nos casos de DC. Em 10 pacientes submetidos ao cateterismo bilateral do seio petroso inferior, um gradiente centro-periferia de ACTH > 3 pós-CRH ou DDAVP teve sensibilidade de 90 por cento e especificidade de 100 por cento para a doença de Cushing.

We studied clinical and laboratorial features of 73 patients with endogenous Cushings syndrome, subdivided as follows: 46 (63 percent) with Cushings disease (CD), 21 (28.7 percent) with an adrenal tumor and 6 (8.2 percent) with ectopic ACTH secretion (EAS). The rate of typical manifestations of hypercortisolism was similar regardless its etiology. In 100 percent of cases of Cushings syndrome we observed serum cortisol levels greater than 1.8 µg/dL in low-dose dexamethasone (DMS) suppression tests, as well as elevation of serum or salivary midnight cortisol. However, urinary free cortisol was normal in 11.5 percent of patients. ACTH levels were suppressed in patients with adrenal tumors, normal or high in CD and always high in EAS. In the 8-mg overnight DMS suppression test, serum cortisol suppression > 50 percent was observed in 78.2 percent of cases of CD and in 33.3 percent of subjects with EAS, while an 80 percent suppression was only seen in CD. After stimulation with CRH or DDAVP an ACTH increase > 35 percent occurred in 81 percent of individuals with CD and 16.6 percent of those with EAS, while an ACTH increase > 50 achieved 100 percent specificity. Moreover, the combination of serum cortisol suppression > 50 percent and an ACTH increase > 35 percent in both tests only occurred in Cushings disease. Pituitary magnetic resonance imaging identified 100 percent of macroadenomas and 59.4 percent of microadenomas in patients with CD. Among 10 patients that underwent bilateral inferior petrosal sinus sampling, a central-to-peripheral ACTH gradient > 3 after CRH or DDAVP had 90 percent sensitivity and 100 percent specificity for Cushings disease.

A clinico-pathological study of Cushing's syndrome at the University Hospital of the West Indies and a review of the literature

Cushing's syndrome is an uncommon but important disease. Twenty-one confirmed cases of spontaneous Cushing's syndrome were documented at the University Hospital of the West Indies over a 21-year period. They were predominantly young females (F:M ratio of 17:4; mean age 25 years and 3 months). The commonest presenting symptoms were amenorrhoea (41) and obesity (19). Common clinical features were cushingnoid features (95), hypertension (76) and hirsutism (82). Twenty-nine per cent had frank hyperglycaemia. Cushing's syndrome was due to Cushing's disease in 10 cases, adrenal adenoma in 3 and adrenal carcinoma in 2 cases. In 4 cases with presumed adrenal hyperplasia, the histology was either unavailable or was not consistent with the diagnosis. Two cases appear now to have had the ectopic ACTH Syndrome. Adrenalectomy was the commonest treatment offered. There were no intra-operative or post-operative deaths but recurrence was common after subtotal adrenalectomy in Cushing's disease. Twenty-seven per cent of the patients developed Nelson's syndrome, which was fatal in 50. Long-term hormone replacement therapy was unnecessary after surgery for adrenal adenomas. Treatment of Cushing's syndrome was well tolerated by the patients.

The ectopic ACTH syndrome and superior vena cava obstruction due to a malignant carcinoid tumour of the thymus

We report the case of a 28-year-old African Caribbean woman with Cushing's syndrome and superior vena cava obstruction secondary to an ACTH-secreting carcinoid tumour of the thymus. The case highlights the problems which may be encountered in performing the 2-day high dose dexamethasone suppression test but clinicians are reminded that this test or any other dynamic test is absolutely essential for elucidating the cause of ACTH-dependent Cushing's Syndrome.

O valor do teste de estímulo com o hormônio liberador da corticotrofina ovino (oCRH) no diagnóstico diferencial da síndrome de Cushing / The value of the stimulus test with ovine corticotropin-releasing hormone (oCRH) in the differential diagnosis of the Cushing syndrome

A caracterizaçao do CRH ovino (oCRH) trouxe novas perspectivas para o diagnóstico diferencial da síndrome de Cushing (SC). Aplicamos o teste de estímulo com oCRH (l mug/kg peso, IV em bolo) para estudo da reserva hipofisária (ACTH) e adrenal (cortisol) em 17 indivíduos controles normais (CN) e 32 pacientes com SC (doença de Cushing [DC] n=24; adenoma adrenocortical [AA] n=6 e secreçao ectópica de ACTH [SE] n=2). Os CN elevaram significantemente seus níveis de ACTH (basal: 28,9 + 12,7; pico: 59,3.ñ 17,6 pg/ml; média ñ DP) e de cortisol (basal: 10, 1.ñ3,4; pico: 18,3 ñ 5,1 mul/dí) após o oCRH. Os pacientes com DC apresentaram níveis basais mais elevados de ACTH (61,7.ñ 58,2 pg/ml) e de cortisol (22,2 ñ 12,5 mug/dl), que se elevaram significantemente após o oCRH (l8l,3 + l32,9 pg/ml e 37,9 + l7,5 mug/dl, respectivamente). Os pacientes com AA apresentaram níveis de ACTH basais (7,4 ñ 3,1 pg/ml) e no pico da resposta (l6,O ñ l3,1 pg/ml) menores que os dos CN e DC. Os níveis basais de cortisol (l9,6 + 6,9 mug/dl) foram maiores que os dos CN, mas nao mudaram após o oCRH (l9,8 ñ 5,7 mug/dl). Os dois pacientes com SE mostraram níveis basais altos de ACTH (307,7 e 102,8 pg/ml) que se elevaram (para 582,4 e 785,4 pg/ml) com o oCRH. Em um o cortisol aumentou de 17,7 para 30,2 mug/dl, mas no outro nao houve mudança (de 6,3 para 6,2 mug/dl). A resposta ao teste foi considerada positiva quando o pico de ACTH foi > 37,7 pg/ml e /ou o incremento de cortisol foi > 2O por cento, o que aconteceu nos CN, DC e (excepcionalmente) em um paciente com SE. A resposta do cortisol ao oCRH mostrou sensibilidade de 100 por cento e especificidade de 87,5 por cento na discriminaçao entre SC hipofisária e extra-hipofisária, em comparaçao com os 75 por cento conseguidos com a supressao pela dexametasona em doses elevadas (8 ou 16 mg em dose única). A eficácia diagnostica é aumentada com a associaçao dos dois testes. Assim, o teste de estímulo com oCRH é útil e prático na determinaçao do diagnóstico diferencial da SC.