Cushing Syndrome: Diagnostic Workup and Imaging Features, With Clinical and Pathologic Correlation

Personalized Management of Malignant and Non-Malignant Ectopic Mediastinal Thyroid: A Proposed 10-Item Algorithm Approach

We aimed to analyze the management of the ectopic mediastinal thyroid (EMT) with respect to EMT-related cancer and non-malignant findings related to the pathological report, clinical presentation, imaging traits, endocrine profile, connective tissue to the cervical (eutopic) thyroid gland, biopsy or fine needle aspiration (FNA) results, surgical techniques and post-operatory outcome. This was a comprehensive review based on revising any type of freely PubMed-accessible English, full-length original papers including the keywords "ectopic thyroid" and "mediastinum" from inception until March 2024. We included 89 original articles that specified EMTs data. We classified them into four main groups: (I) studies/case series (n = 10; N = 36 EMT patients); (II) malignant EMTs (N = 22 subjects; except for one newborn with immature teratoma in the EMT, only adults were reported; mean age of 62.94 years; ranges: 34 to 90 years; female to male ratio of 0.9). Histological analysis in adults showed the following: papillary (N = 11/21); follicular variant of the papillary type (N = 2/21); Hürthle cell thyroid follicular malignancy (N = 1/21); poorly differentiated (N = 1/21); anaplastic (N = 2/21); medullary (N = 1/21); lymphoma (N = 2/21); and MALT (mucosa-associated lymphoid tissue) (N = 1/21); (III) benign EMTs with no thyroid anomalies (N = 37 subjects; mean age of 56.32 years; ranges: 30 to 80 years; female to male ratio of 1.8); (IV) benign EMTs with thyroid anomalies (N = 23; female to male ratio of 5.6; average age of 52.1 years). This panel involved clinical/subclinical hypothyroidism (iatrogenic, congenital, thyroiditis-induced, and transitory type upon EMT removal); thyrotoxicosis (including autonomous activity in EMTs that suppressed eutopic gland); autoimmune thyroiditis/Graves's disease; nodules/multinodular goiter and cancer in eutopic thyroid or prior thyroidectomy (before EMT detection). We propose a 10-item algorithm that might help navigate through the EMT domain. To conclude, across this focused-sample analysis (to our knowledge, the largest of its kind) of EMTs, the EMT clinical index of suspicion remains low; a higher rate of cancer is reported than prior data (18.8%), incident imagery-based detection was found in 10-14% of the EMTs; surgery offered an overall good outcome. A wide range of imagery, biopsy/FNA and surgical procedures is part of an otherwise complex personalized management.

Management of small cell lung cancer complicated with paraneoplastic Cushing's syndrome: a systematic literature review

Paraneoplastic Cushing's syndrome (PCS) is a rare, but clinically important feature of small cell lung cancer (SCLC) that is associated with even worse prognosis. To identify key considerations in comprehensive management of SCLC patients complicated with PCS, we conducted a systematic review of relevant reports on PubMed and Web of Science, focusing on SCLC with PCS cases. The systematic review analyzed 61 reports published between 1985 and 2022 with a total of 157 SCLC patients included. Out of the 157 patients, 132 (84.1%) patients across 58 (95.1%) reports were diagnosed with ectopic Cushing's syndrome. The immunohistochemical (IHC) staining for adrenocorticotropic hormone (ACTH) was performed on 30 (19.1%) patients across 22 (36.1%) reports and demonstrated encouraging performance. For treatment, chemotherapy and ketoconazole were utilized in 50 (81.97%) and 24 (39.34%) reports, respectively. Regarding cause of death, infection and cancer were equally frequent, each being recorded in 17 (27.87%) reports. To conclude, the majority of PCS cases in SCLC patients were caused by ectopic hormone secretion. In order to make a differential diagnosis, it is recommended to utilize IHC staining for a specific hormone such as ACTH or corticotropin-releasing hormone. In the comprehensive treatment of SCLC with PCS patients, effective management of hypercortisolism and potent safeguarding against infection play two crucial roles. Ultimately, further confirmations are required regarding the specificity and accuracy of IHC staining technique as well as the efficacy and safety of immunotherapy in the treatment of SCLC with PCS patients.

Clinical utility of nuclear imaging in the evaluation of pediatric adrenal neoplasms

Adrenal neoplasms rarely occur in children. They can be diagnosed in the presence of endocrine, metabolic or neurological problems, an abdominal mass, more rarely an adrenal incidentaloma, or in the context of an adrenal mass discovered in the evaluation of childhood cancer including hematologic malignancy. According to standard medical practice, pediatric malignancies are almost always evaluated by ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography ([¹⁸F]FDG PET/CT). Nuclear imaging using specific radiotracers is also an important tool for diagnosing and staging neuroblastoma, pheochromocytoma, hormone hypersecretion, or indeterminate adrenal masses. The Hippocratic oath "primum non nocere" encourages limitation of radiation in children per the ALARA concept (as low as reasonably achievable) but should not lead to the under-use of nuclear imaging because of the potential risk of inaccurate diagnosis or underestimation of the extent of disease. As in adults, nuclear imaging in children should be performed in conjunction with hormone evaluation and morphological imaging.

The Mount Sinai Clinical Pathway for the Diagnosis and Management of Hypercortisolism due to Ectopic ACTH Syndrome

Neoplasms that secrete ectopic ACTH may cause severe, life-threatening hypercortisolism. These tumors are often difficult to localize and treat, requiring a comprehensive and systematic management plan orchestrated by a multidisciplinary team. The Mount Sinai Adrenal Center hosted an interdisciplinary retreat of experts in adrenal disorders and neuroendocrine tumors with the aim of developing a clinical pathway for the management of Cushing syndrome due to ectopic ACTH production. The result was institutional recommendations for the diagnosis, localization, surgical approaches to intrathoracic tumors and bilateral adrenalectomy, perioperative and postoperative medical management of hypercortisolism and its sequelae. Specific recommendations were made regarding the timing and selection of therapies based on the considerations of our team as well as a review of the current literature. Our clinical pathway can be applied by other institutions directly or serve as a guide for institution-specific management.

Simultaneous pituitary and adrenal adenomas in a patient with non ACTH dependent Cushing syndrome; a case report with literature review

Introduction

Cushing syndrome is a rare disorder with a variety of underlying etiologies, that can be exogenous or endogenous (adrenocorticotropic hormone (ACTH)-dependent or ACTH-independent). The current study aims to report a case of ACTH-independent Cushing syndrome with adrenal adenoma and nonfunctioning pituitary adenoma.

Case report

A 37–year–old female presented with amenorrhea for the last year, associated with weight gain. She had a moon face, buffalo hump, and central obesity. A 24-hour urine collection for cortisol was performed, revealed elevated cortisol. Cortisol level was non-suppressed after administering dexamethasone. MRI of the pituitary region revealed a pituitary microadenoma, and the CT scan of the abdomen with adrenal protocol revealed a left adrenal adenoma.

Discussion

Early diagnosis may be postponed due to the variety of clinical presentations and the referral of the patient to different subspecialists based on their dominant symptoms (gynecological, dermatological, cardiovascular, psychiatric); it is, therefore, critical to consider the entire clinical presentation for correct diagnosis.

Conclusion

Due to the diversity in the presentation of CS, an accurate clinical, physical and endocrine examination is always recommended.

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Cushing syndrome (CS) is a rare disorder with a variety of underlying etiologies.

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CS is expected to affect 0.2 to 5 people per million per year.

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Adrenal-dependent CS is an uncommon variant of CS.

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This study reports a rare occurrence of pituitary and adrenal adenoma with CS.

Ultra-High-Field 7 T Magnetic Resonance Imaging Including Dynamic and Static Contrast-Enhanced T1-Weighted Imaging Improves Detection of Secreting Pituitary Microadenomas

OBJECTIVE

A prospective preoperative evaluation of 7 T ultra-high-field magnetic resonance imaging (MRI) in patients with suspected pituitary microadenomas for both adenoma detection and intrasellar localization compared with 3 T MRI was carried out.

MATERIALS AND METHODS

Patients underwent prospective preoperative standardized 3 and 7 T MRI. A distinct qualitative (lesion detection, intrasellar lesion location) and quantitative (lesion diameters, T1/T2 signal intensity ratio of the lesion to normal pituitary gland tissue) analysis was performed, along with an evaluation of image quality (IQ) regarding overall IQ, anatomical parameters, and artifacts; the findings of the qualitative analysis were compared with intraoperative findings and endocrinological outcomes.

RESULTS

Sixteen patients (mean age, 43 ± 16 years; 13 women) with pituitary microadenomas were included. Using 7 T MRI allowed the detection of 15 microadenomas-3 more than 3 T MRI. In addition, 7 T MRI allowed more precise lesion localization with 93.75% (15/16) agreement with intraoperative findings, compared with 75% (12/16) agreement using 3 T MRI. Lesion diameters showed no significant difference between 3 and 7 T MRI. T1 and T2 signal intensity ratio between microadenomas and normal pituitary gland tissue were higher in 7 T MRI than in 3 T MRI. The overall IQ and the IQ of each anatomical parameter of 7 T MRI were rated higher than those of 3 T MRI. No significant differences in susceptibility or head motion artifacts were observed between 3 and 7 T MRI; however, 7 T MRI was more susceptible to pulsation artifacts.

CONCLUSION

Ultra-high-field MRI surpasses 3 T MRI in pituitary microadenoma detection and enables more precise delineation with higher correlation with intraoperative findings. Thus, 7 T sellar imaging is a promising option-especially in previously magnetic resonance-negative patients with endocrinologically confirmed hormone oversecretion-and helps reduce the need for invasive diagnostics.

Cushing Disease

Cushing disease is a disorder of hypercortisolemia caused by hypersecretion of adrenocorticotropic hormone by a pituitary adenoma and is a rare diagnosis. Cushing disease presents with characteristic clinical signs and symptoms associated with excess cortisol, but diagnosis is difficult and often relies on repeated and varied endocrinologic assays and neuroradiologic investigations. Gold standard treatment is surgical resection of adrenocorticotropic hormone-secreting pituitary adenoma, which is curative. Patients require close endocrinologic follow-up for maintenance of associated neuroendocrine deficiencies and surveillance for potential recurrence. Medications, radiation therapy, and bilateral adrenalectomy are alternative treatments for residual or recurrent disease.

Factors predicting prolonged glucocorticoid therapy in patients with adrenal insufficiency after laparoscopic adrenalectomy. Case report

Introduction and importance

Adrenal insufficiency (AI) is common after adrenalectomy for Primary Adrenal Cushing's syndrome (PACS), due to the inhibition of the Hypothalamic-Pituitary-Adrenal Axis (HPAA) by the functioning adrenal mass. The treatment of post-surgical AI is based mainly on glucocorticoid supplementation therapy. To date, however, there is no known predicting factor of the duration of supplementation therapy in patients treated with laparoscopic adrenalectomy for PACS.

Case presentation

We report the case of a 22-year-old Caucasian female who presented with dyspnea, osteoporosis, vertebral collapses and fractures of the pelvis. The diagnosis of ACTH-independent Cushing's syndrome was provided. Abdominal MRI revealed a left adrenal mass suggestive for adrenal adenoma, highly suggestive for PACS. The patient underwent left laparoscopic adrenalectomy. After surgery, glucorticoid supplementation therapy was started. More than A-year steroid replacement therapy was necessary before the patient completely recovered the function of the HPAA. During this period the patient was strictly followed up in order to adjust pharmacologic treatment, thus allowing to investigate the possible causes of such a slow and hard recover of the contralateral adrenal gland function.

Conclusion

AI is common after adrenalectomy for PACS due to HPAA suppression. The duration of steroid replacement therapy may be vary depending on patient's characteristics and may be uncommonly long, as in our case. We concluded the not only cortisol and ACTH level, but also radiological findings, such as the size of the mass, its functional activity as well as the hypotrophy or atrophy of the contralateral adrenal gland may be predictive of the duration of the steroid therapy. These factors, if correctly studied before surgery, may be of help in tailoring the postoperative management of the patients after adrenalectomy.

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Adrenal insufficiency is common after adrenalectomy for secreting masses.

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In some cases long-lasting glucocorticoid replacement therapy is required before regular function of the contralateral adrenal gland is restored.

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The high level of cortisol may lead to strong suppression of the Hypothalamic-Pituitary-Adrenal Axis (HPAA), that in turn may lead to hypotrophy of the contralateral adrenal gland.

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No predictive factor of the need for prolonged steroid therapy has been reported in the literature to date. However, some radiological findings, such as the width of the contralateral adrenal gland is associated to the need of a prolonged glucocorticoid replacement therapy in the post-operative time.

Development of Ga-68 DOTA-CRH for PET/CT Imaging of ACTH-Dependent Cushing's Disease: Initial Study

Purpose: Adrenocorticotropic hormone (ACTH)-dependent Cushing's disease accounts for 75% cases of the endogenous Cushing's syndrome. The size of lesion is usually very small, which results in false-negative magnetic resonance imaging (MRI) even after biochemical confirmation of the disease. Corticotrophin-releasing hormone (CRH) the key controller of hypothalamus-pituitary--adrenal axis binds to CRH receptor R1 and R2. CRH R1 is overexpressed in pituitary adenomas. The present study aims to target these overexpressed receptors with Ga-68-DOTA-CRH for noninvasive imaging of ACTH-dependent pituitary adenomas. Materials and Methods: Custom-synthesized 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-CRH peptide was purified by high performance liquid chromatography (HPLC) and characterized by mass spectra. Postradiolabeling optimization with Ga-68, quality control tests were carried out to ensure the suitability of Ga-68 DOTA-CRH for intravenous administration. A pilot study consisting of 15 patients including 6 known cases of macroadenoma underwent Ga-68-DOTA-CRH regional brain positron emission tomography/computed tomography (PET/CT). The optimal imaging time and biodistribution studies were performed in five patients' whole-body and serial brain PET/CT imaging. Lesion activity was determined as SUVmax and correlated with CE-MRI and histopathology of excised tissue. Results: A retention time of 11.3 min and mass of 5145 Da was observed on HPLC and mass spectra. Radiolabeling yield of >98% was achieved under optimized conditions using 25-100 μg of conjugated peptide for 10-22 mCi of Ga-68. The quality control results were in agreement with acceptable criteria. Ga-68-DOTA-CRH was able to delineate ACTH secreting corticotropinoma in all 15 patients. Physiological uptake of radiotracer was observed in liver and spleen with diffused marrow activity. Excretion was noted by renal route. Imaging results were in correlation with CE-MRI and histopathology of excised tissue. Conclusion: Ga-68-DOTA-CRH PET/CT is a promising molecular imaging modality for detection of ACTH-dependent microadenoma.

Portable Chemiluminescence-Based Lateral Flow Assay Platform for the Detection of Cortisol in Human Serum

In this study, we developed the portable chemiluminescence (CL)-based lateral flow assay (LFA) platform for the detection of cortisol in human serum. Cortisol is well-known as a stress hormone due to its high relevancy for human mental and physical health, such as hypertension or depression. To date, a number of optical devices have provided the sensitive determination of levels of analytes. However, this modality type still requires costly optical modules. The developed CL platform is simply composed of two detection modules along with a loading part for the LFA strip. The LFA membrane contains gold nanoparticle probes conjugated with antibodies against cortisol and horseradish peroxidase (HRP), which can also efficiently increase the luminescent signal by providing many areas for anti-cortisol antibody and HRP. The measured voltage signals coming from the photodiode in a CL reader were compared with a standard microplate reader for the evaluation of accuracy. The linear range observed for cortisol was measured to be 0.78–12.5 μg/dL (R² = 0.99) with a limit of detection (LOD) of 0.342 μg/dL. In addition, the CL-LFA reader showed a high correlation (R² = 0.96) with the standard cortisol console (COBAS 8000, Roche), suggesting that our developed CL-based LFA platform can be usable in situ.

Cortisol-Producing Adrenal Adenomas With Intense Activity on 68Ga-Pentixafor PET/CT

ABSTRACT

CXC chemokine receptor type 4 as a G-protein-coupled receptor has been confirmed to be highly expressed in functional adrenocortical adenomas. 68Ga-pentixafor, a CXC chemokine receptor type 4-specific ligand, has been reported as a promising tracer to evaluate functional nature of adrenal adenomas. We report intense 68Ga-pentixafor activity of cortisol-producing adrenal adenomas in 2 patients with adrenocorticotropic hormone-independent Cushing syndrome.

Imaging of Adrenal-Related Endocrine Disorders

Endocrine disorders associated with adrenal pathologies can be caused by insufficient adrenal gland function or excess hormone secretion. Excess hormone secretion may result from adrenal hyperplasia or hormone-secreting (ie, functioning) adrenal masses. Based on the hormone type, functioning adrenal masses can be classified as cortisol-producing tumors, aldosterone producing tumors, and androgen-producing tumors, which originate in the adrenal cortex, as well as catecholamine-producing pheochromocytomas, which originate in the medulla. Nonfunctioning lesions can cause adrenal gland enlargement without causing hormonal imbalance. Evaluation of adrenal-related endocrine disorders requires clinical and biochemical workup associated with imaging evaluation to reach a diagnosis and guide management.

Adrenocortical hyperplasia: a review of clinical presentation and imaging

Adrenal hyperplasia is non-malignant enlargement of the adrenal glands, which is often bilateral. It can be incidental or related to indolent disease process and may be related to benign or malignant etiologies causing biochemical alterations in the hypothalamic-pituitary-adrenal axis which controls steroidogenesis and in particular cortisol production. Clinical significance of the adrenal hyperplasia is variable ranging from asymptomatic finding to serious manifestations of Cushing syndrome. This is often associated with anatomical changes in the adrenal glands, which typically manifests as diffuse and sometimes nodular enlargement of the adrenal glands radiologically. Approaching adrenal hyperplasia requires careful clinical and biochemical evaluation in correlation with imaging review to differentiate ACTH-dependent and ACTH-independent etiologies. CT is the primary modality of choice for adult adrenal imaging owing to reproducibility, temporal and spatial resolution and broader access, while MRI often serves a complimentary role. Ultrasound and MRI are most commonly used in pediatric cases to evaluate congenital adrenal hyperplasia. This article will discuss the clinical presentation and imaging features of different types and mimics of adrenal cortical hyperplasia.

Cushing's Syndrome in a Patient With Rathke's Cleft Cyst and ACTH Cell Hyperplasia Detected by 11C-Methionine PET Imaging-A Case Presentation

Background: Adrenocorticotropic Hormone (ACTH)-dependent Cushing's Syndrome (CS) is most often caused by a pituitary adenoma. Although rarely, it can also result from pituitary corticotroph cell hyperplasia (CH). Reports on concomitant pituitary lesions including ACTH-producing adenomas and Rathke's cleft cysts (RCCs) have been published. Positron emission tomography (PET), using ¹¹C-labelled-methionine (MET) as a tracer and co-registered with magnetic resonance imaging (MRI) has been shown to be useful in the diagnosis of pituitary collision lesions, however, its role is still under investigation. In this work we present the case of a patient in whom CS was caused by non-adenomatous CH within the wall of an RCC. Case Summary: In 2015 a patient with signs and symptoms of CS was referred to our Department. Biochemical studies repeatedly showed elevated midnight serum cortisol and ACTH levels. Magnetic resonance imaging of the sellar region revealed an RCC and MET-PET/MR showed heterogeneous labelled-methionine metabolism in the vicinity of the cyst's wall. Transsphenoidal surgery resulted in rapid, complete and lasting relief of symptoms. Histopathological examination demonstrated an RCC and CH. Conclusions: Concomitance of pituitary focal lesions is a rare phenomenon. Methionine-labelled PET/MR may be useful in the diagnosis of collision sellar lesions, including CH. Corticotroph cell hyperplasia can present as mild and fluctuating hypercortisolaemia.

Influence of inferior petrosal sinus drainage symmetry on detection of adenomas in Cushing's syndrome

BACKGROUND

Asymmetric inferior petrosal sinuses (IPS) are not infrequently encountered during bilateral IPS sampling. There is little data on whether IPS symmetry influences success in predicting the adenoma side in patients with ACTH-dependent Cushing's syndrome (CS).

OBJECTIVE

To assess the influence of IPS drainage patterns on detection of an adenoma in CS.

METHODS

Retrospective single-center cohort analysis reviewing records of patients with CS and negative MRI findings who subsequently underwent BIPSS.

RESULTS

BIPSS was performed in 38 patients with a mean age of 45±15 years. The overall technical success rate was 97% for bilateral cannulation. Asymmetric IPS were observed in 11 (39%) patients with Cushing's disease (CD). A side-to-side ACTH ratio was not significantly different between patients with symmetric outflow and those with asymmetric outflow at baseline (8.6±2.7 versus 16.4±6.0; P=0.45), but ratios were significantly different after ovine corticotropin-releasing hormone (oCRH) stimulation (6.0±2.5 versus 35.7±22.5; P=0.03). BIPSS correctly predicted the side of the adenoma in 25 (96%) patients with CD. Prediction was better when the venous outflow was symmetric (100%) rather than asymmetric (93%), although the difference was not significant (P=0.42). Remission from CS was achieved in 32 patients (87%), independent of the symmetry of IPS.

CONCLUSIONS

Bearing in mind the sample size of this audit, asymmetric IPS at least do not seem to diminish the accuracy of diagnosis of ACTH-dependent CS, nor do they influence the clinical outcome.

ACTH and cortisol responses to CRH in acute, subacute, and prolonged critical illness: a randomized, double-blind, placebo-controlled, crossover cohort study

Purpose

Low plasma ACTH in critically ill patients may be explained by shock/inflammation-induced hypothalamus-pituitary damage or by feedback inhibition exerted by elevated plasma free cortisol. One can expect augmented/prolonged ACTH-responses to CRH injection with hypothalamic damage, immediately suppressed responses with pituitary damage, and delayed decreased responses in prolonged critical illness with feedback inhibition.

Methods

This randomized, double-blind, placebo-controlled crossover cohort study, compared ACTH responses to 100 µg IV CRH and placebo in 3 cohorts of 40 matched patients in the acute (ICU-day 3–6), subacute (ICU-day 7–16) or prolonged phase (ICU-day 17–28) of critical illness, with 20 demographically matched healthy subjects. CRH or placebo was injected in random order on two consecutive days. Blood was sampled repeatedly over 135 min and AUC responses to placebo were subtracted from those to CRH.

Results

Patients had normal mean ± SEM plasma ACTH concentrations (25.5 ± 1.6 versus 24.8 ± 3.6 pg/ml in healthy subjects, P = 0.54) but elevated free cortisol concentrations (3.11 ± 0.27 versus 0.58 ± 0.05 µg/dl in healthy subjects, P < 0.0001). The order of the CRH/placebo injections did not affect the ACTH responses, hence results were pooled. Patients in the acute phase of illness had normal mean ± SEM ACTH responses (5149 ± 848 pg/mL min versus 4120 ± 688 pg/mL min in healthy subjects; P = 0.77), whereas those in the subacute (2333 ± 387 pg/mL min, P = 0.01) and prolonged phases (2441 ± 685 pg/mL min, P = 0.001) were low, irrespective of sepsis/septic shock or risk of death.

Conclusions

Suppressed ACTH responses to CRH in the more prolonged phases, but not acute phase, of critical illness are compatible with feedback inhibition exerted by elevated free cortisol, rather than by cellular damage to hypothalamus and/or pituitary.

Electronic supplementary material

The online version of this article (10.1007/s00134-018-5427-y) contains supplementary material, which is available to authorized users.

CT and MRI of adrenal gland pathologies

Besides ultrasound and nuclear medicine techniques, computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used to examine adrenal lesions in both symptomatic and asymptomatic patients. Some adrenal lesions have characteristic radiological features. If an adrenal nodule is discovered incidentally, determining whether the lesion is benign or malignant is of great importance. According to their biological behavior, lesions can be divided into benign (mainly: adenoma, hyperplasia, pheochromocytoma, cyst, hemorrhage, cystic lymphangioma, myelolipoma, hemangioma, ganglioneuroma, teratoma) and malignant (mainly: metastases, adrenal cortical carcinoma, neuroblastoma, lymphoma) conditions. In this paper, we review CT/MRI findings of common adrenal gland lesions.

Severe metabolic alkalosis-a diagnostic dilemma

Background

Cushing's syndrome due to ectopic ACTH secretion has been associated with many cancers; most commonly small cell carcinoma of the lung and bronchial carcinoid tumors. Usually, patients who confer this diagnosis have poor prognosis.

Case presentation

A 66-year-old female presented with worsening shortness of breath and weakness over three days. Initial laboratory derangements included severe hypokalemia and metabolic alkalosis. Treatment included high amounts of potassium chloride and acetazolamide. Imaging studies revealed anterior medial right upper lobe lung mass as well as suspicion for many liver metastases. Liver biopsy was sought and was positive for small cell carcinoma.

Conclusion

We describe a case of severe metabolic alkalosis and hypokalemia in a patient with Cushing's syndrome due to ectopic ACTH secretion from small cell lung cancer. To our knowledge, this is the first case identified which exhibited such significant metabolic derangements in the form of serum and arterial blood bicarbonate. As prognosis is quite poor, we recommend swift diagnosis and management.

Stress, Glucocorticoids and Bone: A Review From Mammals and Fish

Glucocorticoids (GCs) are the final effector products of a neuroendocrine HPA/HPI axis governing energy balance and stress response in vertebrates. From a physiological point of view, basal GC levels are essential for intermediary metabolism and participate in the development and homeostasis of a wide range of body tissues, including the skeleton. Numerous mammalian studies have demonstrated that GC hormones exert a positive role during bone modeling and remodeling as they promote osteoblastogenesis to maintain the bone architecture. Although the pharmacological effect of the so-called stress hormones has been widely reported, the role of endogenous GCs on bone mineral metabolism as result of the endocrine stress response has been largely overlooked across vertebrates. In addition, stress responses are variable depending on the stressor (e.g., starvation, predation, and environmental change), life cycle events (e.g., migration and aging), and differ among vertebrate lineages, which react differently according to their biological, social and cognitive complexity (e.g., mineral demands, physical, and psychological stress). This review intends to summarize the endogenous GCs action on bone metabolism of mammals and fish under a variety of challenging circumstances. Particular emphasis will be given to the regulatory loop between GCs and the parathyroid hormone (PTH) family peptides, and other key regulators of mineral homeostasis and bone remodeling in vertebrates.