[Machine learning methods in differential diagnosis of ACTH-dependent hypercortisolism]

AIM

To develop a noninvasive method of differential diagnosis of ACTH-dependent hypercortisolism, as well as to evaluate the effectiveness of an optimal algorithm for predicting the probability of ectopic ACTH syndrome (EAS) obtained using machine learning methods based on the analysis of clinical data.

MATERIALS AND METHODS

As part of a single-center, one-stage, cohort study, a retrospective prediction of the probability of EAS among patients with ACTH-dependent hypercortisolism was carried out. Patients were randomly stratified into 2 samples: training (80%) and test (20%). Eleven machine learning algorithms were used to develop predictive models: Linear Discriminant Analysis, Logistic Regression, elastic network (GLMNET), Support Vector machine (SVM Radial), k-nearest neighbors (kNN), Naive Bayes, binary decision tree (CART), C5.0 decision tree algorithms, Bagged CART, Random Forest, Gradient Boosting (Stochastic Gradient Boosting, GBM).

RESULTS

The study included 223 patients (163 women, 60 men) with ACTH-dependent hypercortisolism, of which 175 patients with Cushing's disease (CD), 48 - with EAS. As a result of preliminary data processing and selection of the most informative signs, the final variables for the classification and prediction of EAS were selected: ACTH level at 08:00 hours, potassium level (the minimum value of potassium in the active stage of the disease), 24-h urinary free cortisol, late-night serum cortisol, late-night salivary cortisol, the largest size of pituitary adenoma according to MRI of the brain. The best predictive ability in a training sample of all trained machine learning models for all three final metrics (ROC-AUC (0.867), sensitivity (90%), specificity (56.4%)) demonstrated a model of gradient boosting (Generalized Boosted Modeling, GBM). In the test sample, the AUC, sensitivity and specificity of the model in predicting EAS were 0.920; 77.8% and 97.1%, respectively.

CONCLUSION

The prognostic model based on machine learning methods makes it possible to differentiate patients with EAS and CD based on basic clinical results and can be used as a primary screening of patients with ACTH-dependent hypercortisolism.

Rare case of renal Ewing sarcoma presenting as ectopic Cushing syndrome in a 12-year-old girl

We present a 12-year-old girl with recent onset weight gain and purple striae over the abdomen. Examination revealed her to be hypertensive. On evaluation for Cushing syndrome (CS), her cortisol and adrenocorticotropic hormone (ACTH) were found to be high. MRI brain showed a suspicious lesion (thought to be pituitary microadenoma). Inferior petrosal sinus sampling was not conclusive of pituitary source of ACTH. High dose dexamethasone suppression test confirmed an ectopic source of ACTH secretion and CT scan revealed a mass in the right kidney which was laparoscopically excised. Histopathology and immunohistochemistry confirmed Ewing sarcoma. Our case highlights the rare presentation of renal Ewing sarcoma (RES) as CS. To the best of our knowledge, this is only the second case report of RES/primitive neuroectodermal tumour of the kidney presenting as CS in paediatric age group and first with a concomitant pituitary incidentaloma.

Cyclic ACTH-secreting thymic carcinoid: a case report and review of the literature

Cyclic Cushing's syndrome (CS) due to thymic carcinoid is a rare disorder. We report a case of cyclic CS due to ectopic adrenocorticotropic hormone (ACTH)-secreting atypical thymic carcinoid tumor and reviewed similar cases published in the literature. Our patient had hypercortisolemia lasting approximately one month, followed by normal cortisol secretion, with relapse one year later. Histopathology revealed an atypical ACTH-positive thymic carcinoid. Ectopic CS can be derived from atypical thymic carcinoids, which can be aggressive tumors with early relapse, suggesting that this type of tumor probably needs aggressive treatment.

[Ectopic Adrenocorticotropic Hormone-Producing Pulmonary Carcinoid Presenting as Cushing's Syndrome after Intrapleural Hyperthermic Chemotherapy]

The patient was a woman in her 70's was referred to our hospital because of an abnormal shadow on chest roentgenogram at an annual medical checkup. Since preoperative examinations suggested lung cancer in the right middle lobe, thoracoscopic right middle lobectomy was planned. However, pleural dissemination was detected at surgery and we changed the treatment plan to the intrapleural hyperthermic chemotherapy. During the postoperative course, facial edema, hypokalemia, and hyperglycemia developed, and the diagnosis of Cushing's syndrome was suggested based on an increase in serum level of adrenocorticotropic hormone (ACTH) and cortisol, and was confirmed by a dexamethasone suppression test. Intrapleural hyperthermic chemotherapy was likely to collapse the ACTH-producing tumor leading Cushing's syndrome.

A man in his sixties with dyspnoea and oedema

BACKGROUND/CASE PRESENTATION

A man in his sixties with chronic obstructive pulmonary disease was hospitalised due to oedema and dyspnoea during the previous weeks. He was hypertensive, with 10 kg weight gain, generalised oedema, proximal myopathy and moon face. The assessment was consistent with ectopic ACTH-dependent Cushing's syndrome. A 15 mm lung tumour was detected on CT, with inconclusive cytological examination, and negative FDG/PET CT and octreotide scintigraphy. He developed necrotising pancreatitis and a duodenal perforation, which were surgically treated. His cortisol levels and Cushingoid appearance normalised after surgery, and it was concluded that his hypercortisolism was part of a physiological response. He remained clinically in habitual shape until two years later, when he again developed Cushingoid stigmata. A new octreotide scintigraphy was negative, but FDG/PET CT revealed increased FDG uptake in the lung lesion. Before a lung biopsy was performed, the patient developed necrotising pancreatitis. He was treated conservatively and died in respiratory failure. Autopsy revealed a NET in the lung and necrotising pancreatitis.

INTERPRETATION

The case demonstrates diagnostic challenges in the assessment of ectopic ACTH-dependent cyclic Cushing's syndrome. Is also suggests that pancreatitis could be triggered by hypercortisolism.

[Often Only a Side Event, but Sometimes Groundbreaking - an Ectopic ACTH Secretion as an Example of a Paraneoplastic Syndrome]

Often Only a Side Event, but Sometimes Groundbreaking - an Ectopic ACTH Secretion as an Example of a Paraneoplastic Syndrome Abstract. Various tumors can cause a paraneoplastic ACTH production, particularly small-cell lung cancers. Patients suffer from a secondary Cushing syndrome with hypokalemia, hypertension, hyperglycemia and edema. There are three therapeutic approaches: treatment of the underlying disease, hormonal inhibition and symptomatic treatment. The prognosis of an ACTH-producing lung cancer is poor due to numerous complications. In the presented case study, the patient refused treatment of the underlying disease, therefore a palliative symptomatic treatment became of great importance.

[A case of ectopic adrenocorticotropic hormone syndrome caused by thymoma]

Cushing's syndrome is a clinically common type of clinical syndrome caused by excessive glucocorticoids. It can be divided into adrenocorticotropic-dependent and independent types according to its etiology. A female patient with Cushing's syndrome is reported to have a clinical manifestation of mild full moon face, masculinization of androgen increase, deeper skin color, elevated blood pressure, and pulmonary infection. The cause is unknown. Radiographic examination indicated that pituitary tumor and adrenal tumors did not exist. Chest enhancement CT examination revealed that the lesion was in the thymus. Thoracoscopy was performed to remove the tumor. Since wound infection occurred after operation, a variety of antibiotics were used for anti-infective treatment, and the wound gradually healed. After 21 months of follow-up, the above symptoms disappeared completely and the prognosis was good in the near future. Postoperative pathological diagnosis was thymic neuroendocrine carcinoma. This is a typical case that the thymoma ectopically secrets adrenocorticotropic hormone, which leads to Cushing's syndrome, referring to ectopic adrenocorticotropic hormone syndrome.

Cushing's Syndrome: A Large Adenoma of Adrenal Gland

A 20-year old  man was admitted for evaluation of Cushing's syndrome. He presented with a history of headache, fatique, mood disorder, hypertension (Blood Pressure 170/120 mmHg), moon face, buffalo hump, striae rubrae.  Cortisol serum laboratory increased  33.53 µgr/dl (Normal range: 3.09 - 16.6µgr/dl). Abdominal CT Scan showed a right adrenal mass diameter 10.53 x 6.83 cm, with calcified and necrotized area.Levels of ACTH < 5 pg/ml (Normal range : 6 - 50 pg/ml), absence hypothalamus pituitary defect in brain MRI angiography lead the primary site on adrenal.Patient was given ketoconazole 600 mg daily to treat hypercortisolemia. The patient underwent laparoscopic right adrenalectomy. Preparation of hydrocortisone 100 mg during anesthesia-surgery to prevent occurrence of adrenal crisis.Patient position was LLD, 11mm trocar port with 0, 30 degree optic, 2 port 5mm was used for working element. Harmonic ultrasoundshear was used for dissection, hemoLock clip to control vascular. Right subcostal incision make to remove adrenal gland. EBL 1000 cc, close monitoring in ICU ward.Hydrocortison was continued 5 days after surgery. Ventilatory support removed in 2 day after surgery. On the fifth day condition stable without signs of adrenal crisis, and the patient sent to elective ward. The pathology report revealed a cushing adenoma of adrenal gland.On the fifth day after surgical intervention,  postoperative cortisol levels at 12 µgr/dl. On seventh day, surgical wound healing was well with minimum dose NSAID orally. Striae thining, ginecomastia, buffalo neck, moon face was reduced.The patient was regularly followed up at Endocrine division, Department of Internal medicine. Moon face have been eliminated, no striae and  good mood condition. Blood pressure was 130/ 70 mmHg (without antihypertensive drugs) and cortisol serum was 4.52 µgr/dL and independent from steroid medication.Multidisciplinary approach including endocrine treatment, prevention adrenal crisis and laparoscopic adrenalectomy procedure have good result for Cushing's syndrome due to adenoma of adrenal gland.

[Comparison of efficacy between the serum cortisol and 24 hour urine free cortisol in combined dexamethasone suppression test in the diagnosis of Cushing syndrome]

OBJECTIVE

To compare the sensitivity and specificity between the 24 hour urine free cortisol (24 h UFC) and serum cortisol in dexamethasone suppression test (DST) in the diagnosis of Cushing syndrome (CS).

METHODS

Combined low dose DST (LDDST) and high dose DST (HDDST) were carried out in 67 cases of CS with surgically confirmed cases in recent 3 years(from January 2011 to November 2015). The serum cortisol and 24 h UFC were collected simultaneously for each subject and the sensitivity and specificity of serum cortisol and 24 h UFC were compared.

RESULTS

There were Cushing disease (CD) group (n=53), ectopic adrenocorticotropic hormone (ACTH) syndrome group (n=7) and ACTH-independent Cushing syndrome group (n=7) according to the etiology of hypercorticordism.There were no significant differences among 3 groups in gender and age.The sensitivity of serum cortisol of different cut off points(50, 110, 140 nmol/L and 50% of control)after LDDST was 97.01%, 86.57%, 83.58% and 70.15% respectively.Meanwhile, the sensitivity of cutoff point of 24 h UFC <32 nmol in combined LDDST was 92.54% in the diagnosis of Cushing syndrome.There was no significant differences in two groups between serum cortisol <110 nmol/L and 24 h UFC <32 nmol.However, the sensitivity of serum cortisol <50 nmol/L was significantly higher than 24 h UFC<32 nmol (P<0.05). Furthermore, in combined HDDST, if the suppression rate was ≥50%, the sensitivity of serum cortisol and 24 h UFC in differentiating the etiology of Cushing disease was 60.38% and 90.57%, and the specificity was 91.43% and 96.00% respectively.There were significant differences between serum cortisol and 24 h UFC in both of sensitivity and specificity (both P<0.05). In addition, if the suppression rate of 24 h UFC in HDDST was adjusted to 60.85% according to receiver operating characteristic (ROC) curve, it could have the best levels of sensitivity (92.6%) with the specificity of 85.7%. If the suppression rate of serum cortisol was adjusted to 61.53% in HDDST according to ROC curve, it could have the best sensitivity (64.8%) with the specificity of 78.6% accordingly.

CONCLUSION

In combined LDDST, the serum cortisol <50 nmol/L had a higher sensitivity than the 24 h UFC<32 nmol when they were used as the criteria in determining the diagnosis of CS.In HDDST, the sensitivity and specificity of suppression rate of 24 h UFC ≥50% were better than serum cortisol to differentiate the etiology of CS.

Ectopic ACTH secretion (EAS) associated to a well-differentiated peritoneal mesothelioma: case report

BACKGROUND

The association between mesotheliomas and ectopic ACTH secretion has been rarely reported; we present the first case of ectopic ACTH secretion (EAS) associated with a well-differentiated peritoneal mesothelioma in whom the high dose dexamethasone suppression test (HDDST) results and plasmatic ACTH levels were similar to those found in Cushing's disease (CD).

CASE PRESENTATION

A 43-year-old hispanic woman with a 20 year history of treatment resistant diabetes mellitus and arterial hypertension. She had a full moon face, a buffalo hump, increased volume in both supraclavicular regions, purple striae in her arms and abdomen, truncal obesity, polymenorrhea and umbilical hernia. A cortisol suppression test with low dose dexamethasone (LDDST) with a result of 16.6 μg/dL and ACTH plasma levels were measured at 32.6 pg/mL. The high dose dexamethasone test suppression percentage was 84.8% and magnetic resonance imaging (MRI) showed no evidence of pituitary alterations, computed tomography (CT) showed images suggestive of uterine fibroid and an intra-abdominal tumor that correlated with an umbilical hernia, which reinforcement after contrast. Surgery was performed, finding uterine fibroids and paracolic tumor implants as well as on the omentum, bladder, bowel, ovaries and appendix. Pathology reported a well-differentiated peritoneal mesothelioma with positive immunohistochemistry for ACTH.

CONCLUSIONS

Although most cases of ectopic secretion of ACTH derive from rapidly-developing lung tumors, with very high plasma ACTH levels and cortisol suppression percentages with high doses of dexamethasone under 60%, there is a small percentage of slow-developing, chronic tumors that are biochemically undistinguishable from Cushing's disease. Following the expert recommendations regarding imaging techniques it is possible to identify the associated tumor in most cases.

[Case of pancreatic endocrine tumor associated with Cushing's syndrome]

A 78-year-old woman was admitted complaining of edema of the bilateral lower extremities and face. Computed tomography (CT) and ultrasonography (US) of her abdomen revealed a pancreatic tumor and multiple liver metastases. After admission, hypokalemia and muscle weakness and edema of the bilateral lower extremities rapidly worsened. The diagnosis of Cushing's syndrome was established based on clinical and biochemical data and endocrine studies. We thought that the primary tumor was a pancreatic endocrine tumor based on the liver tumor biopsy findings, and that the pancreatic tumor and liver metastatic tumors were ectopic ACTH-producing tumors. A case of pancreatic endocrine tumor associated with Cushing's syndrome is relatively rare. We summarize previous reports.

The role of [(18)F]fluorodeoxyglucose positron emission tomography and [(111)In]-diethylenetriaminepentaacetate-D-Phe-pentetreotide scintigraphy in the localization of ectopic adrenocorticotropin-secreting tumors causing Cushing's syndrome

Conventional imaging modalities cannot localize the source of ACTH in 30-50% of patients with Cushing's syndrome (CS) caused by ectopic ACTH secretion (EAS). We prospectively evaluated whether [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) or [(111)In]-diethylenetriaminepentaacetate-D-Phe-pentetreotide (OCT) at higher than standard doses of radionuclide (18 mCi; H-OCT), can detect these tumors. Seventeen patients with presumed EAS based on inferior petrosal sinus sampling results underwent routine anatomical imaging studies [computed tomography (CT) and magnetic resonance imaging (MRI)] and OCT scintigraphy with 6 mCi (L-OCT). Research studies included FDG-PET in all patients and H-OCT if L-OCT was negative. ACTH-secreting tumors were localized in 13 patients and were occult in four. Nine of 17 CT, six of 16 MRI, six of 17 FDG-PET, eight of 17 L-OCT, and one of nine H-OCT studies were true positives. The sensitivity of CT and combined H- and L-OCT scintigraphy was higher (both 53%; 95% confidence interval, 29-76%) than that of MRI (37%; 95% confidence interval, 16-64%) or FDG-PET (35%; 95% confidence interval, 15-61%). FDG-PET did not detect tumors that were occult on CT/MRI. L-OCT was a useful complementary modality to CT and MRI. As H-OCT identified a tumor in one patient with otherwise negative imaging, it should be considered only when other imaging modalities fail to localize the ACTH-secreting tumor in patients with EAS.

A case of ACTH-producing pheochromocytoma associated with pregnancy

Ectopic ACTH syndrome is rarely caused by pheochromocytoma. We report a case of a 28-year-old woman with Cushing's syndrome due to ACTH-producing adrenal pheochromocytoma. She had delivered preterm baby at 32nd week of gestation with 'severe preeclampsia'. After delivery, persistent hypertension accompanied by severe headache led her to being misdiagnosed as Cushing's syndrome due to right adrenal adenoma (normal plasma ACTH level) and cerebral vasculitis of unknown etiology. She was referred to our hospital for surgical treatment. Repeated biochemical studies suggested coexistence of ectopic ACTH syndrome and pheochromocytoma. To reverse her clinical deterioration, right total and left subtotal adrenalectomy was performed with presumptive diagnosis of 1) right adrenal pheochromocytoma causing ectopic ACTH syndrome or 2) coexistence of ACTH-dependent Cushing's syndrome and right adrenal pheochromocytoma. Pathologic examination of right adrenal mass revealed pheochromocytoma which showed strong immunostaining for ACTH. Plasma ACTH and urinary cortisol excretion normalized after surgery, but she succumbed to multiple cerebral infarcts and disseminated intravascular coagulation. Pregnancy and inappropriately low plasma ACTH at initial evaluation might have hampered early diagnosis. To our knowledge, this is the first description of a case with ectopic ACTH syndrome due to pheochromocytoma associated with pregnancy.

Experience in diagnosis and treatment of ectopic ACTH syndrome

OBJECTIVES

To increase the diagnosis and treatment of ectopic ACTH syndrome.

METHODS

The data of 12 ectopic ACTH syndrome patients treated from 1985 to 1999 were retrospectively analyzed.

RESULTS

Twelve patients were diagnosed as having ACTH syndrome by endocrinary test and primary tumors were ascertained by imaging examination. Follow-up from 7 months to 8 years showed 3 out of 5 patients with radical resection of primary tumor died. One patient with bilateral adrenorectomy was still alive. All patients received only chemotherapy except one died.

CONCLUSIONS

Patients with Cushing's syndrome should be evaluated by endocrine test and followed up by imaging screen examination. The key points to increase treatment effect include early detection, localization and resection of primary tumors.

Bronchial carcinoid associated with Cushing's syndrome

Bronchial carcinoid is the most frequent cause of Cushing's syndrome due to ectopic ACTH production. The authors report a case of bronchial carcinoid which diagnosis was difficult because of the presence of pulmonary mycosis, that determined a hypercorticosuprarenalism. Medical treatment with octreotide, ketoconazolo and mitotane was useless, and bilateral suprarenalectomy was performed. A scintigraphy with raced somatostatin revealed a left lung area capting radiation. A CT scan of the thorax revealed a lesion of the lingula and the patient underwent an atypical lung resection with complete solution of the symptom. The problems of diagnosis and treatment of neuroendocrine tumors of the lung are discussed and the importance of SSA in the diagnostic procedure is pointed out.

[Exacerbation of autoimmune hypothyroidism after hemi-hypophysectomy in a patient with Cushing's disease]

A 41 year old woman affected by Cushing's disease underwent hemi-hypophysectomy with removal of an ACTH secreting microadenoma. Forty days later, when normal ACTH, cortisol plasma levels and urinary cortisol levels were restored, features of primary autoimmune hypothyroidism developed. While cortisol levels were elevated serum thyroid hormone levels were normal, serum hormone TSH was at the upper limit of the normal range and serum antimicrosomal antibodies were slightly elevated. It is likely that hypothyroidism already present before surgery was not clinically evident due to the immunosuppressive effect of high cortisol levels. The need to assess thyroid function in patient with hypercortisolism is emphasized with the aim to identify the possible onset of autoimmune thyroid disease when cortisol levels are normalized.

Pancreatic islet cell tumor associated with Cushing's syndrome

Seven female patients with a pancreatic islet cell tumor and Cushing's syndrome are described. Five patients initially had symptoms and signs of hypercortisolism, and two presented with an abdominal mass and had subsequent development of the syndrome. The tumors ranged in size from 2 to 12 cm in diameter, and all were argyrophilic with the Grimelius technique. Four cases had positive immunostaining for adrenocorticotropic hormone; other hormones were identified in four cases. Six of the patients were dead at the time of this report: five with metastatic tumor within 4 years of diagnosis and one 19 years after diagnosis with hepatic metastases of undetermined origin. One patient was alive with hepatic metastases 20 years after operation. Among the 42 known cases of pancreatic islet cell tumor and Cushing's syndrome, the 5-year survival was 16%.

Concurrent Cushing's and Zollinger-Ellison syndromes in a patient with islet cell carcinoma. Case report and review of the literature

This report documents the simultaneous occurrence of Cushing's and Zollinger-Ellison syndromes in a patient with islet cell carcinoma. The clinical concurrence of these two syndromes has been recorded in only three previous case studies, while three other case reports record evidence suggesting the presence of both gastrin and ACTH within the tumor but without clinical sequelae. In the present report, evidence based on multiple clinical and biochemical data supports the concept that both syndromes are a result of "ectopic" hormone production by the tumor.

Ectopic ACTH-producing lung cancer presenting with prostatic metastasis

The case is described of a patient presenting with prostatic symptoms and a biopsy proven neoplasm in the prostate gland. Radical radiotherapy initially given to the pelvis produced satisfactory symptomatic improvement with tumour regression, but the patient subsequently developed endocrine complications which led to the site of the primary carcinoma being reconsidered. The case illustrates the ubiquitous nature of aggressive metastatic cancer.