Cushing's syndrome diagnosed incidentally on CT imaging.

In this case report, we describe an uncommon presentation of Cushing's syndrome in a patient in their 60s who presented to the emergency department with left-sided chest pain. The initial workup for the patient was unremarkable except for an elevated blood pressure and elevated fasting plasma glucose. A CT scan of the chest, abdomen and pelvis was performed, demonstrating a splenic artery thrombus with multiple splenic infarcts, in addition to a combination of macronodular adrenal hyperplasia, bilateral gynecomastia, centripetal fat distribution and suspected mild bone demineralisation. Adrenocorticotropic hormone-independent macronodular adrenal hyperplasia, a rare aetiology responsible for Cushing's syndrome, was raised as a potential unifying diagnosis for the patient's hypercoagulable status, which was subsequently confirmed on an endocrinological investigation. The case report underscores the importance of communicating clinically relevant details to the imaging specialist in combination with considering a broad differential, including endocrine disorders, when evaluating an undifferentiated patient with atypical imaging findings.

[Diagnostic value of bilateral inferior petrosal sinus sampling in various modifications and methods of radiation and radionuclide imaging in the diagnosis and differential diagnosis of ACTH-dependent endogenous hypercortisolism].

AIM: To analyze the diagnostic performance of bilateral inferior petrosal sinus sampling (BIPSS) with desmopressin as a stimulation agent and prolactin measurements to control catheter position with or without the ACTH/prolactin normalized ratio calculation in the differential diagnosis of ACTH-dependent endogenous hypercortisolism, and the diagnostics performance of ectopic ACTH-syndrome (EAS) visualization. MATERIALS AND METHODS: A single-center diagnostic study with a retrospective analysis of the data was carried out. The study included patients with ACTH-dependent endogenous hypercorticism with no visualization of pituitary adenoma on MRI or adenoma sizes less than 6 mm. All patients underwent BIPSS with and without calculation of the ACTH/prolactin normalized ratio. Visualization of an EAS included pituitary MRI (to exclude EAS), whole-body CT scan with contrast, and somatostatin receptor scintigraphy with 99mTc-Tectrotide and CT (99mTc-Tectrotide SPECT). The final verification was based on immunohistochemical confirmation of the tumor or stable remission of Cushing's disease (CD) after surgical treatment. Statistical data processing was carried out by using IBM SPSS Statistics 23. Confidence intervals were calculated using the JavaStat online calculator. RESULTS: 230 BIPSS were performed in 228 patients (166 women, 62 men), of which 178 patients were verified as CD and 50 cases were EAS of various localization. The effectiveness of catheterization of petrosal sinuses was 96.9%. The sensitivity of BIPSS without ACTH/prolactin ratio calculation (n=70) was 95.9% (95% CI 86.3-98.9), specificity was 92% (95% CI 75.0-97.8), for the BIPSS with additional determination of ACTH/prolactin-normalized ratio (n=51) - 97.3% (95% CI 86.2-99.5) and 93.8% (95% CI 71.7-98.9), respectively. The use of the MRI method for this sample of patients had a sensitivity of 60.2% (95% CI 52.6-67.5), specificity of 59.2% (95% CI 44.2-73.0), the total body CT with contrast has a sensitivity of 74% (95% CI 59.7-85.4), specificity of 100% (95% CI 97.95-100). The diagnostic accuracy for 99mTc-Tectrotide SPECT in NET visualization has a sensitivity of 73.3% (95% CI 44.9-92.2), specificity of 100% (95% CI 95.3-100). CONCLUSION: BIPSS with desmopressin stimulation and prolactin measurements to control catheter position, as well as the additional calculation of the ACTH/prolactin-normalized ratio, is an optimal method for the differential diagnosis of EAS. Patients who are identified an EAS on BIPSS may be further referred for 99mTc-Tectrotide SPECT and CT for tumor visualization.

Evaluation of bone-related mechanical properties in female patients with long-term remission of Cushing's syndrome using quantitative computed tomography-based finite element analysis.

BACKGROUND: Hypercortisolism in Cushing's syndrome (CS) is associated with bone loss, skeletal fragility, and altered bone quality. No studies evaluated bone geometric and strain-stress values in CS patients after remission thus far. PATIENTS AND METHODS: Thirty-two women with CS in remission (mean age [±SD] 51 ± 11; body mass index [BMI], 27 ± 4 kg/m2; mean time of remission, 120 ± 90 months) and 32 age-, BMI-, and gonadal status-matched female controls. Quantitative computed tomography (QCT) was used to assess volumetric bone mineral density (vBMD) and buckling ratio, cross-sectional area, and average cortical thickness at the level of the proximal femur. Finite element (FE) models were generated from QCT to calculate strain and stress values (maximum principal strain [MPE], maximum strain energy density [SED], maximum Von Mises [VM], and maximum principal stress [MPS]). Areal BMD (aBMD) and trabecular bone score (TBS) were assessed by dual-energy X-ray absorptiometry (2D DXA). RESULTS: Trabecular vBMD at total hip and trochanter were lower in CS as compared with controls (P < .05). Average cortical thickness was lower, and buckling ratio was greater in CS vs controls (P < .01). All strain and stress values were higher in CS patients vs controls (P < .05). 2D DXA-derived measures were similar between patients and controls (P > .05). Prior hypercortisolism predicted both VM (ß .30, P = .014) and MPS (ß .30, P = .015), after adjusting for age, BMI, menopause, delay to diagnosis, and duration of remission. CONCLUSIONS: Women with prior hypercortisolism have reduced trabecular vBMD and impaired bone geometrical and mechanical properties, which may contribute to an elevated fracture risk despite long-term remission.

Cardiac disease in Cushing's syndrome. Emphasis on the role of cardiovascular magnetic resonance imaging.

BACKGROUND: Cushing's Syndrome (CS) is associated with increased cardiovascular morbidity and mortality. In endogenous CS, cardiovascular mortality remains increased for up to 15 years post remission of hypercortisolism. Similarly, patients with exogenous CS have 4-fold increased incidence of cardiovascular events, regardless of pre-existing cardiovascular disease (CVD). OBJECTIVE: To present the pathophysiology, prognosis, clinical and imaging phenotype of cardiac disease in CS. METHODS: A Pubmed search for cardiac disease in CS over the last 20 years was conducted using combinations of relevant terms. Preclinical and clinical studies, as well as review papers reporting on subclinical heart failure (HF), cardiomyopathy, coronary heart disease (CHD), and cardiovascular imaging were selected. RESULTS: Cardiac disease in CS is associated with direct mineralocorticoid and glucocorticoid receptor activation, increased responsiveness to angiotensin II, ectopic epicardial adiposity, arterial stiffness and endothelial dysfunction, as well as with diabetes mellitus, hypertension, hyperlipidemia, obesity and prothrombotic diathesis. Subclinical HF and cardiomyopathy are principally related to direct glucocorticoid (GC) effects and markedly improve or regress post hypercortisolism remission. In contrast, CHD is related to both direct GC effects and CS comorbidities and persists post cure. In patients without clinical evidence of CVD, echocardiography and cardiac magnetic resonance (CMR) imaging reveal left ventricular hypertrophy, fibrosis, diastolic and systolic dysfunction, with the latter being underestimated by echocardiography. Finally, coronary microvascular disease is encountered in one third of cases. CONCLUSION: Cardiovascular imaging is crucial in evaluation of cardiac involvement in CS. CMR superiority in terms of reproducibility, operator independency, unrestricted field of view and capability of tissue characterisation makes this modality ideal for future studies.

Emerging diagnostic methods and imaging modalities in cushing's syndrome.

Endogenous Cushing's syndrome (CS) is a rare disease characterized by prolonged glucocorticoid excess. Timely diagnosis is critical to allow prompt treatment and limit long-term disease morbidity and risk for mortality. Traditional biochemical diagnostic modalities each have limitations and sensitivities and specificities that vary significantly with diagnostic cutoff values. Biochemical evaluation is particularly complex in patients whose hypercortisolemia fluctuates daily, often requiring repetition of tests to confirm or exclude disease, and when delineating CS from physiologic, nonneoplastic states of hypercortisolism. Lastly, traditional pituitary MRI may be negative in up to 60% of patients with adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (termed "Cushing's disease" [CD]) whereas false positive pituitary MRI findings may exist in patients with ectopic ACTH secretion. Thus, differentiating CD from ectopic ACTH secretion may necessitate dynamic testing or even invasive procedures such as bilateral inferior petrosal sinus sampling. Newer methods may relieve some of the diagnostic uncertainty in CS, providing a more definitive diagnosis prior to subjecting patients to additional imaging or invasive procedures. For example, a novel method of cortisol measurement in patients with CS is scalp hair analysis, a non-invasive method yielding cortisol and cortisone values representing long-term glucocorticoid exposure of the past months. Hair cortisol and cortisone have both shown to differentiate between CS patients and controls with a high sensitivity and specificity. Moreover, advances in imaging techniques may enhance detection of ACTH-secreting pituitary adenomas. While conventional pituitary MRI may fail to identify microadenomas in patients with CD, high-resolution 3T-MRI with 3D-spoiled gradient-echo sequence has thinner sections and superior soft-tissue contrast that can detect adenomas as small as 2 mm. Similarly, functional imaging may improve the identification of ACTH-secreting adenomas noninvasively; Gallium-68-tagged corticotropin-releasing hormone (CRH) combined with PET-CT can be used to detect CRH receptors, which are upregulated on corticotroph adenomas. This technique can delineate functionality of adenomas in patients with CD from patients with ectopic ACTH secretion and false positive pituitary lesions on MRI. Here, we review emerging methods and imaging modalities for the diagnosis of CS, discussing their diagnostic accuracy, strengths and limitations, and applicability to clinical practice.

High-resolution contrast-enhanced MRI with three-dimensional fast spin echo improved the diagnostic performance for identifying pituitary microadenomas in Cushing's syndrome.

OBJECTIVES: To assess the diagnostic performance of high-resolution contrast-enhanced MRI (hrMRI) with three-dimensional (3D) fast spin echo (FSE) sequence by comparison with conventional contrast-enhanced MRI (cMRI) and dynamic contrast-enhanced MRI (dMRI) with 2D FSE sequence for identifying pituitary microadenomas. METHODS: This single-institutional retrospective study included 69 consecutive patients with Cushing's syndrome who underwent preoperative pituitary MRI, including cMRI, dMRI, and hrMRI, between January 2016 to December 2020. Reference standards were established by using all available imaging, clinical, surgical, and pathological resources. The diagnostic performance of cMRI, dMRI, and hrMRI for identifying pituitary microadenomas was independently evaluated by two experienced neuroradiologists. The area under the receiver operating characteristics curves (AUCs) were compared between protocols for each reader by using the DeLong test to assess the diagnostic performance for identifying pituitary microadenomas. The inter-observer agreement was assessed by using the κ analysis. RESULTS: The diagnostic performance of hrMRI (AUC, 0.95-0.97) was higher than cMRI (AUC, 0.74-0.75; p ≤ .002) and dMRI (AUC, 0.59-0.68; p ≤ .001) for identifying pituitary microadenomas. The sensitivity and specificity of hrMRI were 90-93% and 100%, respectively. There were 78% (18/23) to 82% (14/17) of the patients, who were misdiagnosed on cMRI and dMRI and correctly diagnosed on hrMRI. The inter-observer agreement for identifying pituitary microadenomas was moderate on cMRI (κ = 0.50), moderate on dMRI (κ = 0.57), and almost perfect on hrMRI (κ = 0.91), respectively. CONCLUSIONS: The hrMRI showed higher diagnostic performance than cMRI and dMRI for identifying pituitary microadenomas in patients with Cushing's syndrome. KEY POINTS: • The diagnostic performance of hrMRI was higher than cMRI and dMRI for identifying pituitary microadenomas in Cushing's syndrome. • About 80% of patients, who were misdiagnosed on cMRI and dMRI, were correctly diagnosed on hrMRI. • The inter-observer agreement for identifying pituitary microadenomas was almost perfect on hrMRI.

Iliopsoas muscle to visceral fat ratio on CT predicts Cushing's syndrome in elderly females with adrenal tumors.

There is no computed tomography (CT)-based numerical index for predicting Cushing's syndrome (CS) in patients with adrenal incidentalomas. We tested the hypothesis that the iliopsoas muscle (Ip-M) to visceral fat (V-fat) ratio (IVR) on CT may predict CS in elderly female patients with adrenal tumors. We examined the V-fat area, subcutaneous fat (S-fat) area, Ip-M area, V-fat/S-fat ratio, and IVR at the third lumbar vertebra (L3) level using abdominal CT in female patients aged ≥50 years with cortisol-producing adrenal tumor diagnosed with CS or non-functioning adrenal tumor (NFT) in the derivation cohort. We performed receiver operating characteristic (ROC) analysis to evaluate the diagnostic value of the V-fat/S-fat ratio and IVR for predicting CS. We assessed the usefulness of the IVR in a separate validation cohort. In the derivation cohort, the IVR was significantly lower in the 9 patients with CS than in the 15 patients with NFT (p < 0.001). In ROC analysis with a cut-off value of 0.067, the IVR showed a sensitivity of 100%, specificity of 80.0%, positive likelihood ratio (PLR) of 5.000, and negative likelihood ratio (NLR) of 0.000. The area under the curve was significantly higher for the IVR than for the V-fat/S-fat ratio (0.933 vs. 0.704, respectively, p = 0.036). In 23 patients in the validation cohort, the IVR demonstrated a PLR of 5.714 and an NLR of 0.327. The novel IVR index, based on single-slice CT at the L3 level, predicted CS in elderly female patients with adrenal tumors.

Osteoporotic vertebral compression fractures caused by Cushing's syndrome in young women: case report and literature review.

BACKGROUND: Cushing's syndrome is known as an important cause of secondary osteoporosis, characterized by reduction of bone mineral density and potential occurrence of fragility fractures before diagnosis in young population. Therefore, for young patients with fragility fractures, especially in young women, more attention should be paid on glucocorticoid excess caused by Cushing's syndrome, due to relatively higher rate of misdiagnosis, distinct pathological characteristics and different treatment strategies compared with violent fractures and primary osteoporosis related fractures. CASE PRESENTATION: We presented an unusual case of a 26-year-old woman with multiple vertebral compression fractures and pelvis fractures, subsequently diagnosed as Cushing's syndrome. On admission, the radiographic results showed fresh second lumbar vertebra fracture, and old fourth lumbar vertebra and pelvic fractures. The dual energy X-ray absorptiometry of lumbar spine revealed marked osteoporosis, and her plasm cortisol was extremely high. Then, Cushing's syndrome, caused by left adrenal adenoma, was diagnosed by further endocrinological and radiographic examinations. After receiving left adrenalectomy, her plasma ACTH and cortisol values returned to normal level. In term of OVCF, we adopted conservative treatments, including pain management, brace treatment, and anti-osteoporosis measures. Three months after discharge, the patient's low back pain was in complete remission without new onset of pain, and returned to normal life and work. Furthermore, we reviewed the literatures on advancements in the treatment of OVCF caused by Cushing's syndrome, and based on our experiences, proposed some additional perspectives to guide treatment. CONCLUSION: In term of OVCF secondary to Cushing's syndrome without neurological damage, we prefer systematic conservative treatments, including pain management, brace treatment, and anti-osteoporosis measures, to surgical treatment. Among them, anti-osteoporosis treatment has the highest priority because of the reversibility of osteoporosis caused by Cushing's syndrome.

Irreversible Alterations of Susceptibility in Cushing's Disease: A Longitudinal QSM Study.

OBJECTIVES: Chronic exposure to hypercortisolism is associated with accelerated aging and neurodegenerative diseases, while Cushing's disease (CD) is the most common form of endogenous hypercortisolism exposure. This study aimed to assess longitudinal susceptibility changes in CD using quantitative susceptibility mapping (QSM) before and after resolution of hypercortisolism. METHODS: In this study, 24 CD patients and 24 healthy controls underwent magnetic resonance imaging (MRI) with QSM. All CD patients underwent MRI scans before and after the curative operation. RESULTS: After resolution of hypercortisolism, irreversibly altered susceptibility values were found in the anterior cingulate cortex, frontal lobe, caudate, and red nucleus. These alterations were significantly correlated with the changes in gray matter/white matter volumes and clinical features. Additionally, decreased susceptibility was found in several regions in CD patients. CONCLUSION: Chronic exposure to hypercortisolism may be related to susceptibility alterations and significantly correlated with altered brain volumes and clinical features. in CD patients. The decrease of susceptibility might suggest the involvement of the calcium deregulation in these alterations.

Trabecular bone score, bone marrow fat and vertebral fractures in cushing syndrome.

OBJECTIVE: Prediction of fragility fractures in Cushing syndrome (CS) is a challenge since dual energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD) does not capture all the alterations in bone microstructure induced by glucocorticoid excess. In this study we investigated the relationship between trabecular bone score (TBS), bone marrow fat (BMF) and vertebral fractures (VFs) in endogenous CS. DESIGN: Cross-sectional. METHODS: Thirty subjects (7 M and 23 F, mean age 44.8 ± 13.4 yrs, range: 25-71) with active hypercortisolism were evaluated for VFs by quantitative morphometry, BMD and TBS by lumbar spine DXA and BMF by single-voxel magnetic resonance spectroscopy of vertebral body of L3. RESULTS: Subjects with VFs (17 cases; 56.7%) had higher BMF (P = 0.014) and lower BMD T-score (P = 0.012) and TBS (P = 0.004) as compared to those without VFs. Prevalence of VFs resulted to be significantly higher in individuals with impaired TBS as compared to those with normal TBS (77.8% vs. 25.0%; P = 0.008). Among patients with VFs, only 6 (35.3%) had either osteoporosis or "low BMD for age". In logistic regression analysis, impaired TBS maintained the significant association with VFs [odds ratio (OR) 6.60, 95% C.I. 1.07-40.61; P = 0.042] independently of BMF (OR 1.03, 95% C.I. 0.99-1.08; P = 0.152). CONCLUSIONS: TBS might be more accurate than BMF in identifying subjects with active CS and skeletal fragility at risk of VFs. SIGNIFICANCE STATEMENT: Excess in glucocorticoids is associated with alterations in bone remodeling and metabolism, leading to fragility fractures regardless of bone mineral density, making more challenging for the clinician the identification of high-risk population and the definition of preventing strategies. In this context, instrumental parameters suggestive of bone quality alterations and predictive of increased fracture risk are needed. In this study, we found CS patients to have bone quality alterations as indicated by the decreased trabecular bone score and increased bone marrow fat, as measured by DEXA and MRI respectively. Both parameters were associated with high risk of VFs, and were inversely correlated, although TBS seems to be more accurate than BMF in fractures prediction in this clinical setting.

Central venous sampling and magnetic resonance imaging in the diagnosis of ACTH-dependent Cushing's syndrome.

OBJECTIVES: Central venous sampling (CVS) with corticotropin-releasing hormone (CRH) stimulation is a crucial technique in evaluating adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome (CS). We evaluated central venous sampling (CVS) and magnetic resonance imaging (MRI) findings in predicting the localization and lateralization of pituitary microadenomas. METHODS: We analyzed 29 patients with CS who underwent CVS with CRH stimulation and examined with MRI retrospectively. Catheterization to central sinuses was successfully performed in 26 patients. Three patients with variant anatomy or inability to cannulate were diagnosed with CD after examination of pathology. RESULTS: After CVS, among 26 patients, 23 patients were determined to have CD (88.4%) and 2 (7.7%) patients were diagnosed with ectopic ACTH syndrome. One patient was diagnosed with CD postoperatively. While the sensitivity of the CVS was 95.6%, sensitivity of the preoperative pituitary MRI was lower (69.5%). Also, the negative predictive value ratio was higher in CVS than in MRI (66% versus 22%). Diagnostic accuracy in the lateralization of the tumor was high as in CVS as in MRI (76.4% versus 73.9%). CONCLUSION: Central venous sampling with higher sensitivity in the localization of pituitary microadenoma, also has approximately similar diagnostic accuracy in lateralizing the tumor with MRI.

68Ga-DOTATATE PET/CT of ACTH-Independent Cushing Syndrome Due to Ectopic Adrenocortical Adenoma.

ABSTRACT: Adrenocorticotropic hormone-independent Cushing syndrome due to ectopic adrenocortical adenoma is a very rare entity. We herein present a case of a 57-year-old woman who was referred to our hospital with persistent Cushing syndrome after undergoing unnecessary laparoscopic left adrenalectomy. 68Ga-DOTATATE PET/CT revealed increased uptake in the nodule in the right hilum, which was histologically confirmed to be ectopic adrenocortical adenoma. Removal of the tumor was followed by the disappearance of clinical symptoms of Cushing syndrome. In this case, 68Ga-DOTATATE PET/CT contributed to the diagnosis of ectopic adrenocortical adenoma.

Usefulness of 68 Ga-Pentixafor PET/CT on Diagnosis and Management of Cushing Syndrome.

PURPOSE: This pilot study investigated the performance of C-X-C motif chemokine receptor 4 (CXCR4) molecular imaging ( 68 Ga-pentixafor PET/CT) in Cushing syndrome (CS) and the correlation between CXCR4 signaling interactions and glucose metabolism in adrenocorticotropin-cortisol pathway. METHODS: We retrospectively evaluated 31 patients (16 patients with CS and 15 patients with nonfunctioning pituitary or adrenal adenomas). All patients underwent 68 Ga-pentixafor PET/CT, and 11 with pituitary adenoma also underwent 18 F-FDG PET/CT. The diagnosis accuracy of 68 Ga-pentixafor PET/CT was calculated. The correlation between radiouptake along the pituitary-adrenal axis and hormone levels was calculated. RESULTS: Patients with Cushing disease characterized a focal uptake in adrenocorticotropic hormone-producing pituitary adenoma (ACTH-PA). In ACTH-independent CS, there was increased uptake of 68 Ga-pentixafor in adrenal lesions but not in the pituitary fossa. The nonfunctioning pituitary or adrenal adenomas showed negative 68 Ga-pentixafor signal. The one patient with metastatic ectopic ACTH syndrome had multiple 68 Ga-pentixafor-avid lesions. Using the threshold of SUV max >8.5 in the adrenal lesions, the sensitivity and specificity of 68 Ga-pentixafor PET/CT to diagnose cortisol-producing adenoma were 100% and 84.9%. A cutoff SUV max value of 3.0 on 68 Ga-pentixafor PET/CT had 100% sensitivity and specificity for differentiating ACTH-PA. The corresponding hormone level was significantly correlated with uptake of 68 Ga-pentixafor in pituitary adenoma and adrenal tissue but not with glucose metabolism. CONCLUSION: We have characterized the performance of 68 Ga-pentixafor in different subtypes of CS. 68 Ga-pentixafor PET/CT is promising in the differential diagnosis of both ACTH-independent and ACTH-dependent CS. Activated CXCR4 molecular signaling along the pituitary-adrenal axis was found in patients with Cushing disease.

High-dose dexamethasone suppression test is inferior to pituitary dynamic enhanced MRI in the differential diagnosis of ACTH-dependent Cushing's syndrome.

PURPOSE: The differential diagnosis of adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome remains a challenge in clinical practice. The present study was aimed at assessing the diagnostic performance of pituitary dynamic contrast-enhanced magnetic resonance imaging (dMRI), high-dose dexamethasone suppression test (HDDST), and a combination of both tests for patients with ACTH-dependent Cushing's syndrome. METHODS: A total of 119 consecutive patients with ACTH-dependent Cushing's syndrome confirmed surgically were enrolled: 101 with proven Cushing's disease and 18 with proven ectopic ACTH syndrome. All patients underwent pituitary dMRI and HDDST. The sensitivity and specificity of pituitary dMRI, HDDST, and a combination of both tests were determined. RESULTS: The sensitivity and specificity of pituitary dMRI for diagnosing Cushing's disease were 80.2 and 83.3%, respectively, with a positive predictive value of 96.4%. The sensitivity and specificity of HDDST were 70.3 and 77.8%, respectively, with positive predictive value of 94.7%. A combination of both tests showed that the combined criteria of more than 50% suppression of serum cortisol on HDDST and a positive pituitary dMRI finding yielded a high specificity of 94.4 and sensitivity of 59.4%. The combined criteria of more than 68% suppression on HDDST and/or a positive pituitary dMRI finding yielded a sensitivity of 86.1% and specificity of 83.3%. CONCLUSIONS: Pituitary dMRI was superior to HDDST in the differential diagnosis of ACTH-dependent Cushing's syndrome. HDDST is recommended in combination with pituitary dMRI to establish a diagnosis process because of the significantly increased specificity with the combination.

Case Report: A Challenging Localization of a Pulmonary Ectopic ACTH-Secreting Tumor in a Patient With Severe Cushing's Syndrome.

Background: Ectopic adrenocorticotropic syndrome (EAS) is a rare cause of endogenous ACTH-dependent Cushing's syndrome, usually associated with severe hypercortisolism as well as comorbidities. Tumor detection is still a challenge and often requires several imaging procedures. In this report, we describe a case of an ectopic ACTH secretion with a misleading localization of the responsible tumor due to a concomitant rectal carcinoma. Case presentation: A 49-year-old man was referred to our Endocrinology Unit due to suspicion of Cushing's syndrome. His medical history included metastatic rectal adenocarcinoma, diagnosed 5 years ago and treated with adjuvant chemotherapy, radiotherapy and surgical resection. During follow-up, a thoracic computed tomography scan revealed two pulmonary nodules located in the superior and middle lobes of the right lung with a diameter of 5 and 10 mm, respectively. However, these nodules remained radiologically stable thereafter and were not considered relevant. All biochemical tests were suggestive of EAS (basal ACTH levels: 88.2 ng/L, nv 0-46; basal cortisol levels: 44.2 µg/dl, nv 4.8-19.5; negative response to CRH test and high dose dexamethasone suppression test) and radiological localization of the ectopic ACTH-secreting tumor was scheduled. The CT scan revealed a dimensional increase of the right superior lung nodule (from 5 to 12 mm). [68Ga]-DOTA-TOC PET/CT scan was negative, while [18F]-FDG-PET/CT showed a tracer accumulation in the superior nodule. After a multidisciplinary consultation, the patient underwent thoracic surgery that started with two atypical wedge resections of nodules. Frozen section analyses showed a neuroendocrine tumor on the right middle lobe nodule and a metastatic colorectal adenocarcinoma on the superior lesion. Then, a right superior nodulectomy and a right middle lobectomy with mediastinal lymphadenectomy were performed. The final histopathological examination confirmed a typical carcinoid tumor, strongly positive for ACTH. A post-surgical follow-up showed a persistent remission of Cushing's syndrome. Conclusions: The present report describes a case of severe hypercortisolism due to EAS not detected by functional imaging methods, in which the localization of ACTH ectopic origin was puzzled by a concomitant metastatic rectal carcinoma. The multidisciplinary approach was crucial for the management of this rare disease.

Incidentally discovered myelolipomatous adrenal adenomas, including six cases presenting with hypercortisolism.

Most adrenal incidentalomas are non-functioning adenomas that require no treatment. The presence of a myelolipomatous component of adrenal incidentalomas is a rare, but well-known occurrence in both hyperplastic and neoplastic lesions of the adrenal cortex. Although the improvements in abdominal imaging have increased identification of myelolipomatous adrenal cortical adenomas radiologically, due to the rarity of this lesion, the clinical pathological features of these lesions are unclear and can sometimes cause diagnostic difficulty. Eleven patients had surgeries at The University of Texas MD Anderson Cancer Center. Four additional cases were provided from an external collaborator. Of the 15 cases, there were 5 male and 10 female patients, with a median age of 52 years (mean 54 years, range 28-84 years). Clinical presentation included adrenal incidentaloma (n = 9), Cushing syndrome (n = 4, including 1 as a part of Carney complex), and subclinical Cushing syndrome (n = 2, including 1 with bilateral macronodular adrenal hyperplasia). In this study, we present the clinicopathologic features of fifteen myelolipomatous adrenal adenomas, the largest series published thus far.

Diagnostic Role of PET/CT Tracers in the Detection and Localization of Tumours Responsible for Ectopic Cushing's Syndrome.

BACKGROUND/AIM: Positron emission tomography/computed tomography (PET/CT) plays an important role in cancer localization in ectopic Cushing's syndrome (ECS). However, the choice of the optimal tracer for investigation of this disease is still unclear. We aimed to evaluate the diagnostic feasibility of [18F]fluoro-2-deoxyglucose ([18F]FDG), [18F]fluoro-L-dihydroxyphenylalanine ([18F] FDOPA), and [68Ga]-DOTA-1-Nal3-octreotide ([68Ga]-DOTANOC) in ECS. PATIENTS AND METHODS: All PET/CT scans of patients admitted to our department for suspected ECS between 2010 and 2020 were retrospectively analysed. RESULTS: Collectively, 30 PET/CT examinations, 11 with [18F]FDOPA, 11 with [18F]FDG and 8 with [68Ga]GaDOTANOC were conducted for 18 patients eligible for analysis. [18F]FDG detected the tumour in 3/6 of the cases, [18F]FDOPA in 3/4, and [68Ga]GaDOTANOC in 3/3. [18F]FDOPA was the only tracer without false positive results. CONCLUSION: [68Ga]GaDOTANOC and [18F]FDOPA showed superior results compared to [18F]FDG, although the sensitivity of the tracers might be influenced by the aetiology of the tumour underlying the ECS.