Bronchial carcinoid tumors causing Cushing's syndrome: more aggressive behavior and the need for early diagnosis

Visual analysis of lung neuroendocrine tumors based on CiteSpace knowledge graph

Objective

The relevant literatures in the field of pulmonary neuroendocrine tumor were analyzed to understand the lineage, hot spots and development trends of research in this tumor.

Method

The Web of Science core collection was searched for English-language literature about neuroendocrine tumors of the lung published between 2000 and 2022. CiteSpace software was imported for visualization analysis of countries, institutions, co-cited authors and co-cited journals and sorting of high-frequency keywords, as well as co-cited references and keyword co-occurrence, clustering and bursting display.

Results

A total of 594 publications on neuroendocrine tumours of the lung were available, from 2000 to 2022, with an overall upward trend of annual publications in the literature. Authors or institutions from the United States, Italy, Japan and China were more active in this field, but there was little cooperation among the major countries. Co-cited references and keyword co-occurrence and cluster analysis showed that research on diagnostic instruments, pathogenesis, ectopic ACTH signs, staging and prognosis and treatment was a current research hotspot. The keyword bursts suggested that therapeutic approaches might be a key focus of future research into the field for pulmonary neuroendocrine tumors.

Conclusion

Over these 20 years, research related to neuroendocrine tumors of the lung has increased in fervour, with research on diagnostic instruments, pathogenesis, ectopic ACTH signs, staging and prognosis, and treatment being the main focus of research. Therapeutic treatments may be the future research trend in this field.

Elevated Serum Androstenedione Level in a Patient With Ectopic Adrenocorticotropic Hormone Syndrome

Background/Objective

Ectopic Cushing syndrome can be challenging to diagnose when its presentation is atypical. Herein, we highlight features of ectopic adrenocorticotropic hormone (ACTH) syndrome in a patient with worsening hypertension, hypokalemia, ACTH-dependent hypercortisolism, and disproportionate elevation in serum androstenedione levels.

Case Report

A 59-year-old woman presented with rapidly progressing hypertension, severe hypokalemia, confusion, and weakness. Her medical history included well-controlled hypertension receiving amlodipine 5 mg/day, which worsened 3 months prior to admission requiring losartan and spironolactone therapy, with twice daily potassium supplementation. Physical examination was notable for bruising, muscle wasting, thin extremities, facial fullness, and abdominal adiposity despite body mass index 17 kg/m2. Laboratory evaluation showed potassium 2.6 mEq/L (3.5-5.3), morning cortisol >50 mcg/dL (8-25), 24-hour urine cortisol 8369 mcg/day (<50), ACTH 308 pg/mL (<46), androstenedione 398 ng/dL (20-75), dehydroepiandrosterone sulfate 48 mcg/dL (≤430), and testosterone 11 ng/dL (≤4.5) levels. A 3.8-cm carcinoid right lung tumor was identified, and resection was performed with clean margins. Cortisol, androstenedione, and potassium levels rapidly normalized postoperatively and blood pressure returned to baseline, well-controlled on amlodipine.

Discussion

Our case illustrates disproportionate elevation in androstenedione levels despite normal dehydroepiandrosterone sulfate and testosterone in a woman with ectopic ACTH syndrome. Limited reports have observed similar discordance in androgen profiles in ectopic versus pituitary ACTH hypersecretion, potentially attributable to differential activation of androgen biosynthesis.

Conclusion

Adrenal androgen assessment may help differentiate pituitary versus ectopic ACTH secretion in which androstenedione is elevated, but studies are needed to determine whether disproportionate androstenedione elevation reliably predicts the origin of ACTH excess.

Continuing Challenges in the Definitive Diagnosis of Cushing's Disease: A Structured Review Focusing on Molecular Imaging and a Proposal for Diagnostic Work-Up

The definitive diagnosis of Cushing's disease (CD) in the presence of pituitary microadenoma remains a continuous challenge. Novel available pituitary imaging techniques are emerging. This study aimed to provide a structured analysis of the diagnostic accuracy as well as the clinical use of molecular imaging in patients with ACTH-dependent Cushing's syndrome (CS). We also discuss the role of multidisciplinary counseling in decision making. Additionally, we propose a complementary diagnostic algorithm for both de novo and recurrent or persistent CD. A structured literature search was conducted and two illustrative CD cases discussed at our Pituitary Center are presented. A total of 14 CD (n = 201) and 30 ectopic CS (n = 301) articles were included. MRI was negative or inconclusive in a quarter of CD patients. ¹¹C-Met showed higher pituitary adenoma detection than ¹⁸F-FDG PET-CT (87% versus 49%). Up to 100% detection rates were found for ¹⁸F-FET, ⁶⁸Ga-DOTA-TATE, and ⁶⁸Ga-DOTA-CRH, but were based on single studies. The use of molecular imaging modalities in the detection of pituitary microadenoma in ACTH-dependent CS is of added and complementary value, serving as one of the available tools in the diagnostic work-up. In selected CD cases, it seems justified to even refrain from IPSS.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) on diagnosis of Cushing's syndrome

Cushing's syndrome is defined by prolonged exposure to glucocorticoids, leading to excess morbidity and mortality. Diagnosis of this rare pathology is difficult due to the low specificity of the clinical signs, the variable severity of the clinical presentation, and the difficulties of interpretation associated with the diagnostic methods. The present consensus paper by 38 experts of the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology aimed firstly to detail the circumstances suggesting diagnosis and the biologic diagnosis tools and their interpretation for positive diagnosis and for etiologic diagnosis according to ACTH-independent and -dependent mechanisms. Secondly, situations making diagnosis complex (pregnancy, intense hypercortisolism, fluctuating Cushing's syndrome, pediatric forms and genetically determined forms) were detailed. Lastly, methods of surveillance and diagnosis of recurrence were dealt with in the final section.

Comparison of diagnostic efficacy of 18F-FDG PET/CT and 68Ga-DOTANOC PET/CT in ectopic adrenocorticotropic hormone syndrome

PURPOSE

Fluorine-18 (¹⁸F)-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) and gallium-68 (⁶⁸Ga)-somatostatin analog (SSA) PET/CT imaging have been increasingly used in ectopic adrenocorticotropic hormone syndrome (EAS); however, the diagnostic efficacies of these two methods in patients with EAS remain unclear. Our study aimed to compare the diagnostic efficacies of ¹⁸F-FDG PET/CT and ⁶⁸Ga-DOTANOC PET/CT in EAS.

METHODS

The clinical and imaging data of 68 patients with EAS who underwent ¹⁸F-FDG PET/CT and ⁶⁸Ga-DOTANOC PET/CT examinations from December 2016 to April 2021 were analyzed retrospectively, and the diagnostic efficacies of these methods were compared.

RESULTS

In 37 cases, imaging was performed to locate the primary tumor lesion (localization group), and in 31 to evaluate tumor load or metastasis (staging group). Primary tumors were detected in 48.65% (18/37) of the localization group patients. According to scan-based analysis, the tumor lesion detection rates and false positive rates of ¹⁸F-FDG PET/CT imaging and ⁶⁸Ga-DOTANOC PET/CT imaging were 18.92% vs. 45.95% (p < 0.05) and 21.62% vs. 2.70% (p < 0.05) respectively. For lesion-based analysis, the tumor lesion detection rates and false positive rates were 24.13% vs. 58.62% (p >0.05) and 31.04% vs. 3.45% (p < 0.05). In 90.32% (28/31) of the staging group patients, 286 of 292 lesions were confirmed as tumor lesions. Based on scan analysis, the detection rates and false positive rates of ¹⁸F-FDG PET/CT imaging and ⁶⁸Ga-DOTANOC PET/CT imaging were 83.87% vs. 67.74% (p > 0.05) and 12.90% vs. 9.68% (p > 0.05) respectively. Based on lesion analysis, the detection rate and false positive rates were 93.84% vs. 54.80% (p < 0.05) and 1.37% vs. 1.03%(p > 0.05).

CONCLUSION

⁶⁸Ga-DOTANOC PET/CT imaging may be more suitable than ¹⁸F-FDG PET/CT for identifying the primary tumor in patients with EAS, while ¹⁸F-FDG PET/CT may be more advantageous than ⁶⁸Ga-DOTANOC PET/CT for patients with suspected metastasis.

Ectopic Cushing's syndrome due to thymic neuroendocrine tumours: a systematic review

Knowledge of ectopic Cushing's syndrome (CS) due to thymic neuroendocrine tumours (NETs) comes from short series or single cases. Our aim is to perform a systematic review using PubMed, Embase, Scopus, Ovid Medline and Biosis Previews of all cases with ectopic CS due to thymic NETs reported in the last 40 years and describe one illustrative patient attended in our institution. Search of literature: From 162 patients, 58.6% were male and mean age was 34.6 ± 13.9 years-old. Median of symptoms until diagnosis was 6 [2-24] months and 62% had aggressive CS. Imaging was positive in 93.7% (chest X-ray), 97.8% (computed tomography), 80.7% (somatostatin receptor scintigraphy) and median tumour size was 47 [25-68.5] mm. At presentation, 18% had localized disease, 26.2% locally invasive and 55.7% advanced. Eighty-eight present underwent surgery and histological subtypes were atypical (46.7%), typical (30.4%) and carcinoma (21.7%). Tumour persisted or recurred in 70.1%, 63% received radiotherapy and 45.2% chemotherapy. Follow-up median was 26.6 [14.5-57.5] months and mortality was reported in 35.8% with median survival of 38 [19-60] months. MEN-1 mutation was referred in 3.1%. Comparatively, carcinomas had aggressive CS more frequently while atypical showed advanced disease more often. In conclusion, thymic NETs causing ectopic CS are presented as aggressive hypercortisolism in the middle aged population. The disease is commonly extended at diagnosis and persists or recurs after surgery in most patients with a short term high mortality.

Clinical and laboratory characteristics and results of treatment of patients with ACTH-producing neuroendocrine tumors of various localization

Aim. To study the clinical, biochemical characteristics, treatment results and follow-up of patients with ectopic ACTH syndrome EAS (ACTH adrenocorticotropic hormone ). Materials and methods. A retrospective, observational, single-center study of 130 patients with EAS. Demographic information of patients, medical history, results of laboratory and instrumental investigations at the pre- and postoperative stages and follow-up of EAS were analyzed. Results. The mean age at the diagnosis ranged from 12 to 74 years (Me 40 years [28; 54]). The duration of the disease from the onset of symptoms to the verification of the diagnosis varied from 2 to 168 months (Me 17.5 months [7; 46]). Eighty-one (62,3%) patients had bronchopulmonary NET, 9 thymic carcinoid, 7 pancreatic NET, 5 pheochromocytoma, 1 cecum NET, 1 appendix carcinoid tumor, 1 medullary thyroid cancer and 25 (19.2%) had an occult source of ACTH. The median follow-up period of patients was 27 months [9.75; 61.0] with a maximum follow-up of 372 months. Currently, primary tumor was removed in 82 (63.1%) patients, bilateral adrenalectomy was performed in 23 (18%) patients, in 16 of them there was an occult source of ACTH-producing NET and in 7 patients in order to control hypercortisolism after non-successful surgical treatment. Regional and distant metastases were revealed in 25 (19.2%) patients. At the time of the last observation 59 (72%) patients were exhibited a full recovery, 12 (14.6%) had relapse of the disease and 26 (20%) died from multiple organ failure (n=18), pulmonary embolism (n=4), surgical complications (n=2), disseminated intravascular coagulation syndrome (n=1) or COVID-19 (n=1). Conclusion. In our cohort of patients bronchopulmonary NET are the most frequent cause of EAS (62.3%). Surgical treatment leads to remission of hypercortisolism in 72% cases; the proportion of relapse (14.6%) and fatal outcome (20%) remains frequent in EAS.

Characterization of Outcomes by Surgical Management of Lung Neuroendocrine Tumors Associated With Cushing Syndrome

IMPORTANCE

Ectopic adrenocorticotropic hormone secretion from lung tumors causing Cushing syndrome are associated with high rates of morbidity. Optimal management remains obscure because knowledge is based on rare reports with few patients.

OBJECTIVE

To characterize the outcomes of lung neuroendocrine tumors associated with Cushing syndrome.

DESIGN, SETTING, AND PARTICIPANTS

An observational case series review from 1982 to 2020 was conducted in a single institution referral center. Kaplan-Meier analysis estimated disease-free survival (DFS). Participants underwent curative-intent surgery for a lung neuroendocrine tumor causing Cushing syndrome.

EXPOSURES

Lobectomy or pneumonectomy vs sublobar resection.

MAIN OUTCOMES AND MEASURES

Disease-free survival, disease persistence/recurrence.

RESULTS

Of the 68 patients, the median age was 41 years (range, 17-80 years), 42.6% (29 of 68) were male, 81.8% (54 of 66) were White, with a mean follow-up after surgery was 16 months (range, 0.1-341 months). Lobectomy was the most common procedure (48 of 68 [70.6%]), followed by wedge resection (16 of 68 [23.5%]) and segmentectomy (3 of 68 [4.4%]). Video-assisted thoracoscopic surgery was performed in 19 of 68 (27.9%) of patients. Surgical morbidity was 19.1% (13 of 68), and perioperative mortality was 1.5% (1 of 68). Lymph node positivity was 37% (22 of 59) when evaluable. The overall incidence of persistence/recurrence was 16.2% (11 of 68) with a median time to recurrence of 55 months (range, 18-152 months). The median DFS was reached in 12.7 years (0.1-334 months). There were no statistical differences in DFS based on tumor size, stage (8th edition TNM), whether full systematic lymphadenectomy was performed or not, nodal status, or surgical approach.

CONCLUSIONS AND RELEVANCE

In this case series study, neuroendocrine pulmonary tumors associated with Cushing syndrome had increased nodal metastasis, higher recurrence, and lower DFS than quiescent bronchopulmonary carcinoid tumors, but many patients experienced favorable outcomes. This observation is underscored by the discordance of TNM-stage classifications vs prognosis. Observing no difference in surgical techniques, the implication may be that a lung-sparing approach could suffice. These results may reflect the intrinsic importance of the hormone physiology instead of the carcinoid biologic factors.

New types of localization methods for adrenocorticotropic hormone-dependent Cushing's syndrome

The management of endogenous Cushing's syndrome (CS) typically involves two key steps: (i) confirmation of autonomous hypercortisolism and (ii) localization of the cause to guide treatment. Adrenocorticotropic hormone (ACTH)-dependent CS is most commonly due to a pituitary corticotrope tumor which may be so small as to evade detection on conventional magnetic resonance imaging (MRI). Although biochemical testing (e.g., corticotropin stimulation; dexamethasone suppression) can provide an indication of the likely origin of ACTH excess, bilateral inferior petrosal sinus catheterization offers greater accuracy to distinguish pituitary-driven CS [Cushing's Disease (CD)] from the ectopic ACTH syndrome [EAS, e.g., due to a bronchial or pancreatic neuroendocrine tumor (NET)]. In patients with CD, 40-50% may not have a pituitary adenoma (PA) readily visualized on standard clinical MRI. In these subjects, alternative MR sequences (e.g., dynamic, volumetric, fluid attenuation inversion recovery) and higher magnetic field strength (7T > 3T > 1.5T) may aid tumor localization but carry a risk of identifying coincidental (non-causative) pituitary lesions. Molecular imaging is therefore increasingly being deployed to detect small ACTH-secreting PA, with hybrid imaging [e.g., positron emission tomography (PET) combined with MRI] allowing precise anatomical localization of sites of radiotracer (e.g., ¹¹C-methionine) uptake. Similarly, small ACTH-secreting NETs, missed on initial cross-sectional imaging, may be detected using PET tracers targeting abnormal glucose metabolism (e.g., ¹⁸F-fluorodeoxyglucose), somatostatin receptor (SSTR) expression (e.g., ⁶⁸Ga-DOTATATE), amine precursor (e.g., ¹⁸F-DOPA) or amino acid (e.g., ¹¹C-methionine) uptake. Therefore, modern management of ACTH-dependent CS should ideally be undertaken in specialist centers which have an array of cross-sectional and functional imaging techniques at their disposal.

Clinical Heterogeneity of Ectopic ACTH Syndrome: A Long-Term Follow-Up Study

OBJECTIVE

Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a heterogeneous condition caused by neuroendocrine neoplasms (NENs) located in the lungs, thymus, or pancreas. Our purpose was to evaluate the long-term outcome of these patients.

METHODS

Retrospective study at a referral center. The charts of 164 patients with Cushing syndrome, followed at our center from 1993 to 2019, were analyzed.

RESULTS

EAS was found in 16 patients (9.75%, 9 women, mean age 36.01 years) who had been followed for a median of 72 months. The source of EAS was a NEN in 10 patients (8 bronchial and 2 thymic carcinoid tumors) and a mixed corticomedullary tumor, consisting of a pheochromocytoma and an adrenocortical carcinoma in 1 patient. In 2 of the 6 patients initially considered to have occult EAS, the source of the ACTH excess became apparent after adrenalectomy, whereas in the remaining 4 (25%) patients, it has remained occult. Of the 11 patients in whom resection of the NEN was attempted, 10 patients achieved an early remission (91%), but 4 (25%) of these patients had a recurrence during follow-up (biochemically and clinically silent in 2 patients). Three patients died (18.75%): the young woman with the mixed corticomedullary tumor, a man with a thymic NEN that evolved into a neuroendocrine (NE) carcinoma after 11 years of follow-up, and a woman with a bronchial NEN.

CONCLUSION

The course of EAS varies according to tumor type and grade. Some patients have a protracted course, whereas others may evolve into neuroendocrine carcinomas.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone; CS = Cushing syndrome; CT = computed tomography; CV = coefficient of variation; EAS = ectopic ACTH syndrome; IQR = interquartile range; NEN = neuroendocrine neoplasm; SCCL = small cell carcinoma of the lung; TSS = transsphenoidal surgery; UFC = urinary free cortisol.

Diagnosis and management of small pulmonary atypical carcinoid tumor associated with Cushing syndrome

Ectopic adrenocorticotropic hormone (ACTH) syndrome is rare and identification of its source is often challenging. We report the case of an ectopic Cushing syndrome in a young adult male secondary to an occult ACTH producing atypical carcinoid tumor. Extensive biochemical and imaging workup was unrevealing. The diagnosis was aided by Ga-DOTA PET scan demonstrating a suspicious left upper lobe lung nodule. The patient underwent video-assisted thoracoscopic exploration with wedge resection and mediastinal lymphadenectomy of a T2aN2M0 atypical carcinoid, resulting in the normalization of ACTH levels and complete resolution of symptoms. The role of a Ga-DOTA PET scan in diagnosing pulmonary carcinoid tumors and their management are discussed.

ACTH-producing tumorlets and carcinoids of the lung: clinico-pathologic study of 63 cases and review of the literature

Adrenocorticotropic hormone (ACTH)-secreting lung carcinoids represent the principal cause of ectopic Cushing syndrome, but the prevalence of ACTH expression and the association between ACTH production and Cushing syndrome in lung carcinoids have scarcely been investigated. In addition, available information on the prognostic meaning of ACTH production is controversial. The aims of this multicentric retrospective study, also including a review of the literature, were to describe the clinico-pathologic features of ACTH-producing lung carcinoids, to assess recurrence and specific survival rates, and to evaluate potential prognostic factors. To identify ACTH production in 254 unselected and radically resected lung carcinoids, we used a double approach including RT-PCR (mRNA encoding for pro-opiomelanocortin) and immunohistochemistry (antibodies against ACTH and β-endorphin). Sixty-three (24.8%) tumors produced ACTH and 11 of them (17.4%), representing 4.3% of the whole series, were associated with Cushing syndrome. The median follow-up time was 71 months. The 10-year overall and specific survival rates were 88.5% and 98.2%, respectively, with difference neither between functioning and nonfunctioning tumors nor between ACTH-positive and ACTH-negative carcinoids. At univariate analysis, histological type (typical or atypical) and Ki67 index significantly correlated with tumor recurrence. The literature review identified 172 previously reported patients with functioning ACTH-secreting lung carcinoids, and the meta-analysis of survival showed that 92% of them were alive after a mean follow-up time of 50 months. Our results demonstrate that ACTH-producing lung carcinoids are not rare, are not always associated with Cushing syndrome, and do not represent an aggressive variant of lung carcinoid.

Carcinoid tumors of the thymus and Cushing's syndrome: Clinicopathologic features and current best evidence regarding the cell of origin of these unusual neoplasms

It is uncertain whether thymic neuroendocrine tumors (NET) associated with Cushing's syndrome (CS) produce corticotropin-releasing hormone (CRH) and adrenocorticotropin hormone (ACTH) and whether the thymus contains ACTH and/or CRH cells that could originate NET. The clinicopathologic features of 5 typical (TC) and 6 atypical carcinoids (ATC), 10 additional non-neoplastic thymi, 6 adrenal glands with bilateral nodular hyperplasia and 8 adrenal cortical adenomas were reviewed. Representative slides were immunostained for ACTH and CRH. Four (36.4%) of the 11 patients had CS. The incidence of Masaoka stage IV was higher (p < 0.0001) in patients with ATC than TC. Only 2 (18.1%) of the 11 patients were alive at follow-up. Ten NET were CRH immunoreactive and 6 were ACTH immunoreactive. Thymic NET with CS exhibited stronger immunoreactivity for ACTH and CRH than those without CS. Non-neoplastic thymi exhibited scattered ACTH and CRH immunoreactive cells. Normal adrenal cortex and glands with bilateral nodular hyperplasia showed diffuse CRH immunoreactivity while adrenal adenomas showed no or only focal CRH immunoreactivity. Literature review showed no association between thymic NET and adrenal adenomas. The thymus contains CRH and ACTH immunoreactive cells that are probably the origin of thymic NET. Neoplasms associated with CS exhibit strong immunoreactivity for both hormones, suggesting that CRH probably plays a role in the pathogenesis of CS. As adrenals with bilateral nodular hyperplasia exhibit diffuse CRH immunoreactivity and adrenal cortical adenomas either lack this finding or show few immunoreactive cells, this marker may be useful to distinguish these lesions.

Bronchopulmonary carcinoid with a single lymph node metastasis causing ectopic Cushing's syndrome

Bronchial carcinoid tumors (BCTs) represent a subgroup of bronchopulmonary neuroendocrine tumors which have the ability to produce neuropeptides. Merely 2% of BCTs secrete ACTH and less than 1% of patients with Cushing's syndrome (CS) have a BCT. Typical BCTs rarely metastasize. We here present a patient with ectopic CS caused by a typical BCT, which metastasized into a lymph node. This case suggests that the diagnostic work up of CS should be wide and include ectopic ACTH-secreting BCT, and that ACTH secretion can be correlated to a more aggressive type of typical BCTs.

Paraneoplastic Cushing's syndrome associated with bronchopulmonary carcinoid tumor in youth: A case report and review of the literature

Paraneoplastic Cushing's syndrome (CushingPS) caused by bronchopulmonary carcinoid tumors presents a diagnostic challenge for clinicians. The present study reports the case of an 18-year-old male patient presenting with rapid weight gain, polyuria, polydipsia and progressive muscle weakness. Chemical and imaging findings suggested ectopic secretion of adrenocorticotropin. Whole-body ¹⁸fluorine-fluorodeoxyglucose (¹⁸FDG-PET/CT) positron-emission tomography revealed an increased uptake of ¹⁸FDG-PET/CT in the right middle lung mass and lobar lymph node. Postoperative pathology confirmed the presence of a typical carcinoid, as well as a lobar lymph node metastasis. The patient underwent a right middle lobectomy with mediastinal lymph node resection, which resulted in symptom clearance, followed by rapid weight loss. No CushingPS or tumor recurrence was observed at the 3-month postoperative follow-up.

Surgical treatment of ectopic adrenocorticotropic hormone syndrome with intra-thoracic tumor

BACKGROUND

The study was to review the clinical manifestations and laboratory examinations of ectopic adrenocorticotropic hormone (ACTH) syndrome, and to analyze the efficacy of surgical treatment.

METHODS

The clinical data, surgical therapy, and outcome of 23 cases of ectopic ACTH syndrome accompanied by intra-thoracic tumors were reviewed. The tumors were removed from all the patients according to the principles of radical resection.

RESULTS

The tumors were confirmed as associated with ectopic ACTH secretion in 19 cases. Hyperglycemia and hypokalemia were recovered, while plasma cortisol, plasma ACTH and 24-hour urinary free cortisol (UFC) levels were significantly reduced after surgery in these 19 cases. Recurrences of the disease were found in six cases during following-up, and five of them died.

CONCLUSIONS

The thoracic cavity should be a focus in routine examinations of patients with symptoms of Cushing's syndrome (CS), because ectopic ACTH-producing tumors are commonly found in bronchus/lung and mediastinum. Despite the incidence of the pulmonary nodule secondary to opportunistic infection in some cases, surgery is still the first choice if the tumor is localized. The surgical procedure should be performed according to the principles in resection of lung cancer and mediastinal tumor. The surgical efficacy is significant for short-term periods; however, the recurrence of the disease in long-term periods is in great part related to distal metastasis or relapse of the tumor.

Cushing's like syndrome in typical bronchial carcinoid a case report and review of the literature

Cushing’s syndrome occurred in 1–5% of cases of bronchial carcinoids. In this paper we describe a case of typical bronchial carcinoid in a nonsmoker young male with clinical manifestations mimicking a Cushing’s syndrome. The patient performed chest radiograph and computed tomography. Fiberoptic bronchoscopy revealed the presence of an endobronchial mass occluding the bronchus intermedius. A rigid bronchoscopy was necessary for the conclusive diagnosis and for partial resection of the intraluminal tumor. Despite of the presence of Cushingoid features, the normal blood levels of ACTH and cortisol excluded the coexistence of a Cushing’s syndrome.

PET imaging in ectopic Cushing syndrome: a systematic review

Cushing syndrome due to endogenous hypercortisolism may cause significant morbidity and mortality. The source of excess cortisol may be adrenal, pituitary, or ectopic. Ectopic Cushing syndrome is sometimes difficult to localize on conventional imaging like CT and MRI. After performing a multilevel thoracoabdominal imaging with CT, the evidence regarding the use of radiotracers for PET imaging is unclear due to significant molecular and etiological heterogeneity of potential causes of ectopic Cushing's syndrome. In our systematic review of literature, it appears that GalLium-based (Ga68) somatostatin receptor analogs have better sensitivity in diagnosis of bronchial carcinoids causing Cushing syndrome and FDG PET appears superior for small-cell lung cancers and other aggressive tumors. Further large-scale studies are needed to identify the best PET tracer for this condition.

Severe Cushing's syndrome related to a small pulmonary carcinoid with widespread dissemination

Cushing's syndrome (CS) is characterized by the overproduction of cortisol that may result in significant morbidity and mortality if left untreated. CS is very rarely caused by ectopic adrenocorticotropic hormone production from several tumors, although pulmonary neuroendocrine tumors (pNETs) are the most common etiology. It is controversial whether such tumors are more clinically aggressive than other pNETs. We herein report an unusual case of severe ectopic CS caused by a small pulmonary carcinoid in the lung with massive neoplastic dissemination to the liver. We highlight and discuss the unusual clinical onset, with diagnostic and therapeutic criticism, of this rare entity.

Thoracic and duodenopancreatic neuroendocrine tumors in multiple endocrine neoplasia type 1: natural history and function of menin in tumorigenesis

Mutations of the multiple endocrine neoplasia type 1 (MEN1) gene lead to loss of function of its protein product menin. In keeping with its tumor suppressor function in endocrine tissues, the majority of the MEN1-related neuroendocrine tumors (NETs) show loss of heterozygosity (LOH) on chromosome 11q13. In sporadic NETs, MEN1 mutations and LOH are also reported, indicating common pathways in tumor development. Prevalence of thymic NETs (thNETs) and pulmonary carcinoids in MEN1 patients is 2-8%. Pulmonary carcinoids may be underreported and research on natural history is limited, but disease-related mortality is low. thNETs have a high mortality rate. Duodenopancreatic NETs (dpNETs) are multiple, almost universally found at pathology, and associated with precursor lesions. Gastrinomas are usually located in the duodenal submucosa while other dpNETs are predominantly pancreatic. dpNETs are an important determinant of MEN1-related survival, with an estimated 10-year survival of 75%. Survival differs between subtypes and apart from tumor size there are no known prognostic factors. Natural history of nonfunctioning pancreatic NETs needs to be redefined because of increased detection of small tumors. MEN1-related gastrinomas seem to behave similar to their sporadic counterparts, while insulinomas seem to be more aggressive. Investigations into the molecular functions of menin have led to new insights into MEN1-related tumorigenesis. Menin is involved in gene transcription, both as an activator and repressor. It is part of chromatin-modifying protein complexes, indicating involvement of epigenetic pathways in MEN1-related NET development. Future basic and translational research aimed at NETs in large unbiased cohorts will clarify the role of menin in NET tumorigenesis and might lead to new therapeutic options.

[Cushing syndrome: Physiopathology, etiology and principles of therapy]

The most frequent cause of Cushing's syndrome is iatrogenic, as Cushing's syndrome is the unavoidable consequence of long-term glucocorticoid treatment using more than 7.5 mg prednisone per day. The most frequent cause of endogenous Cushing's syndrome is Cushing's disease (CD), which is an ACTH dependent hypercortisolism linked to a pituitary corticotroph adenoma. This adenoma is often very small, its diagnosis may require bilateral inferior petrosal sinus sampling and the first line treatment of CD is transsphenoidal surgery by an expert neurosurgeon. The second line treatments include drugs that can act either on the pituitary adenoma or on adrenal steroidogenesis, pituitary radiotherapy or bilateral adrenalectomy. Ectopic ACTH dependent Cushing's syndrome is linked either to poorly differentiated endocrine tumors with a very poor prognosis, such as small cell lung cancer, or to well differentiated endocrine tumors, such as bronchial carcinoid tumors, which have a good prognosis when treated by surgery, but may be very difficult to localize. Adrenal Cushing's syndromes, which are independent of pituitary ACTH secretion, include adrenal cortex carcinoma, which requires abdominal surgery with extended adrenalectomy by an expert surgeon, adrenal adenoma which is treated by laparoscopic unilateral adrenalectomy and bilateral macronodular hyperplasia, whose surgical treatment may require unilateral or bilateral adrenalectomy. Treatment of Cushing's syndrome generally leads to spectacular clinical results, which must not hide the fact that the reversibility of some signs is actually incomplete. This underlines the need for a timely multidisciplinary management of the patients by an expert team.