Two cases of pancreatic neuroendocrine tumors with ectopic ACTH syndrome during their disease course

Pancreatic neuroendocrine tumors (PanNETs) are rare malignant tumors that occur in the pancreas. They are divided into functioning and non-functioning tumors based on the presence or absence of their specific hormonal hyper-expression symptoms. Adrenocorticotropic hormone (ACTH)-producing PanNETs are rare, functional tumors, and their clinical characteristics and outcomes have not been well reported.Here, we report the cases of two patients with PanNETs who presented with ectopic ACTH syndrome (EAS) during the course of their disease. Case 1 involved a non-functioning PanNET at the time of surgery. During treatment for recurrent liver metastases, the patient presented with EAS and tumor-associated hypercalcemia, probably due to ACTH and parathyroid hormone-related peptide (PTHrP) production from the liver tumor. Case 2 was a gastrinoma, and similar to Case 1, this patient presented with EAS during the treatment of recurrent liver metastases.It is not uncommon for patients with PanNETs to have multiple hormones and develop secondary hormone secretion during their disease course, although tumor phenotypes differ between primary and metastatic sites. In patients with functioning PanNETs, symptom control with anti-hormonal therapy is essential, in addition to anti-tumor therapy, especially for EAS, which is an endocrine emergency disease that requires prompt diagnosis and treatment.

Machine Learning May Be An Alternative To BIPSS In The Differential Diagnosis Of ACTH-Dependent Cushing's Syndrome

OBJECTIVE

This study aimed to develop machine learning (ML) algorithms for the differential diagnosis of adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome (CS) based on biochemical and radiological features.

METHODS

Logistic regression algorithms were used for ML, and the area under the receiver operating characteristics curve (AUROC) was used to measure performance. We used Shapley Contributed Comments (SHAP) values, which help explain the results of the ML models to identify the meaning of each feature and facilitate interpretation.

RESULTS

A total of 106 patients, 80 with Cushing's disease (CD) and 26 with ectopic ACTH syndrome (EAS), were enrolled in the study. The ML task was created to classify patients with ACTH-dependent CS into CD and EAS. The average AUROC value obtained in the cross-validation of the logistic regression model created for the classification task was 0.850. The diagnostic accuracy of the algorithm was 86%. The SHAP values indicated that the most important determinants for the model were the 2-day 2-mg dexamethasone suppression test, the > 50% suppression in the 8-mg high-dose dexamethasone test, late-night salivary cortisol, and the diameter of the pituitary adenoma. We have also made our algorithm available to all clinicians via a user-friendly interface.

CONCLUSION

ML algorithms have the potential to serve as an alternative decision support tool to invasive procedures in the differential diagnosis of ACTH-dependent CS.

Clinical features and risk factors for postoperative recurrence in patients with Cushing's syndrome of different etiologies

The clinical characteristics of Cushing's syndrome (CS) vary with etiology, and few studies have investigated the risk factors affecting CS recurrence after surgery. This retrospective study involved 202 patients diagnosed with CS between December 2012 and December 2022. The patients were divided into three groups according to etiology: Cushing's disease (CD), adrenocortical adenoma (ACA), and ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS). Of the patients with CS, 41.9% had hypokalemia and 15.0% had hypophosphatemia. The cortisol levels were negatively correlated with blood potassium, blood chlorine, and blood phosphorus. Moreover, 22.4% of patients had an abnormal heart structure, 11.2% had centripetal remodeling, 5.6% had centripetal hypertrophy, and 5.6% had centrifugal hypertrophy. The overall recurrence rate of CS caused by pituitary tumors and adrenal adenoma was 25.7%. The recurrence times were longer in the ACA group versus the CD group, in patients < 50 years of age versus in patients ≥ 50 years old group, and in patients with CD with tumors ≥ 1 cm versus tumors < 1 cm. Age, preoperative cortisol level, postoperative cortisol level, and absolute neutrophil value were closely related to postoperative recurrence, and etiology was an independent predictor of tumor recurrence in patients with CS. The results of this study showed that CS caused by different etiologies showed different clinical manifestations, blood electrolyte characteristics, and that CS could affect patient cardiac structure and function. Etiology is an independent predictor of tumor recurrence in patients with CS.

Clinical profile and treatment outcomes of patients with ectopic ACTH syndrome compared to Cushing disease: a single-center experience

PURPOSE

We aimed to evaluate and compare the clinical, biochemical and radiological profile and outcomes of patients with ectopic ACTH syndrome (EAS) and Cushing disease (CD) treated over a period of 10 years (2013-2022).

METHODS

In this ambispective observational study, we collected data for 146 patients with ACTH-dependent CS (EAS, n = 23; CD, n = 94; occult ACTH source, n = 29). Relevant details were filled in a predesigned proforma and outcomes were ascertained at the most recent visit.

RESULTS

EAS was more common in males (65.2 vs. 27.6%, p < 0.001). Patients with EAS had a shorter duration of symptoms [12 (6-12) vs. 31.5 (15-48) months, p < 0.001] and were more likely to have hypokalemia (82.6 vs. 21.0%, p = 0.001), pedal edema (65.2 vs. 34.2%, p = 0.015), weight loss (34.8 vs. 4.0%, p < 0.001) and systemic infection (30.4 vs. 6.5%, p = 0.006). They also had significantly higher 8 a.m. serum cortisol, midnight serum and salivary cortisol and 8 a.m. plasma ACTH levels. Bronchial carcinoid (n = 10, 43.5%) was the most common etiology of EAS. Bilateral adrenalectomy was performed in 11 (47.8%) patients with EAS. Eight patients (34.8%) with EAS died at the last follow-up, of whom 7 (87.5%) had metastatic disease. In CD group, overall remission rate was 69.4% (56.1%, early and 13.3%, delayed) and 26.3% of patients with an initial remission had recurrence.

CONCLUSIONS

Bronchial carcinoid was the most common cause of EAS in our cohort. Bilateral adrenalectomy was performed in approximately every 1 in 2 patients with EAS and approximately every 1 in 3 patients expired till the last follow-up.

Biochemical testing to differentiate Cushing's disease from ectopic ACTH syndrome

The differential diagnosis of ACTH-dependent Cushing's syndrome is often a diagnostic challenge that has been debated in numerous studies. In this short article, we will discuss the performance and main drawbacks of the biochemical tests used for this diagnosis.

A case report

•

Nephrolithiasis is a frequent and underestimated complication of Cushing’s syndrome (CS), prevalence soars up to 50 % in adult patients with active CS, and 25% in cured patients in whom certain abnormalities contribute to stone recurrence

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Ectopic ACTH secretion (EAS) is a less common cause of Cushing syndrome and is seen in 5 to 10% of cases with endogenous hypercortisolemia. Sudden and dramatic onset of CS often suggests an ectopic ACTH-secreting tumor.

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There is no information in any urological clinical practice guideline in relation to management of nephrolithiasis in Cushing’s syndrome, follow-up in glucocorticoid-induced nephrolithiasis should be tailored to each patient.

An ACTH-secreting tumor hidden in a congenitally hypoplastic left lung

Ectopic adrenocorticotrophic hormone (ACTH) syndrome has historically been a therapeutic challenge because of the difficulty localizing occult ACTH-secreting tumours. Here, we report a case of a 67-year-old woman with ectopic ACTH syndrome and had an ACTH-secreting tumour hidden within a congenitally hypoplastic left lung. A satisfactory therapeutic outcome was obtained after left pneumonectomy was performed on patient in this case.

Characteristics and outcomes of the Finnish ectopic ACTH syndrome cohort

PURPOSE

Ectopic ACTH syndrome (EAS) is rare. We established a national cohort to increase awareness and address unmet needs.

METHODS

The Finnish national EAS cohort includes 60 patients diagnosed in 1997-2016. We assessed clinical features, diagnostic work-ups, treatments, incidence, and outcomes of subgroups occult tumor (OT), well-differentiated neuroendocrine tumor G1/G2 (NETG1/G2) and NET G3/neuroendocrine carcinoma (NETG3/NEC).

RESULTS

The distribution of OT, NETG1/G2, and NETG3/NEC was 10 (17%), 20 (33%), and 30 (50%), respectively; and median follow-up 22 months (0-249). Annual incidence (0.20-0.93 per million inhabitants) and tumor subgroups (OT vs. NEC) varied across the country. The longest diagnostic delay from EAS onset to radiological tumor identification was 48 months. In NET/NEC, 6/50 (12%) were diagnosed 1-24 years before EAS onset. Osteoporotic fractures (32%) and severe infections (55%) were common. The CRH stimulation test accurately diagnosed EAS in 25/31 (81%). Metyrapone (≤6 g daily, prescribed in 88%) was well tolerated. In NETG1/G2, 13/20 (65%) underwent curative resection of the primary tumor; four experienced recurrence within 2-12 years. In OT, 70% underwent bilateral adrenalectomy. Five-year overall survival in OT, NETG1/G2, and NETG3/NEC was 90%, 55%, and 0%, respectively (P < 0.001). Morning cortisol, hypokalemia, infections, metastatic disease, and acute onset were negative, whereas resection of the primary tumor and bilateral adrenalectomy were positive predictors of survival.

CONCLUSIONS

NET/NEC may precede EAS onset by several years. In NETG1/G2, recurrences may occur > 10 years after successful primary surgery. Tumor subgroup (OT, NETG1/G2, NEC) was an independent predictor of survival.

A rare case of ectopic ACTH syndrome with rhabdomyolysis

BACKGROUND

Manifestations of hypokalaemia in ectopic adrenocorticotropic hormonesyndrome(EAS) vary from mild muscle weakness to life-threatening arrhythmia. Herein, we present a rare case of EAS with concomitant rhabdomyolysis(RM) as a result of intractable hypokalaemia.

CASE PRESENTATION

A 64-year-old man was admitted for limb weakness and facial hyperpigmentation for 2 weeks. Lab tests revealed intractable hypokalaemia (lowest at 1.8 mmol/L) and metabolic alkalosis. The diagnosis of RM was based on a creatine kinase(CK)level of 5 times the upper limit. The elevated CK and myohemoglobin (Mb) levels returned to within the normal range after the alleviation of hypokalaemia. The patient was diagnosed with ACTH-dependent Cushing's syndrome (CS) based on unsuppressed serum cortisol after a low-dose dexamethasone suppression test(LDDST) and remarkably elevated ACTH levels. The diagnosis of EAS was made based on the results of a high-dose dexamethasone suppression test(HDDST) and bilateral inferior petrosal sinus sampling(BIPSS). Multiple lymph nodes in the left supraclavicular fossa, right root of neck, mediastinum and bilateral hili of the lung were found with abnormal uptake of ⁶⁸Ga-DOTA-NOC. Mediastinoscopic lymph node biopsy was performed. The pathological diagnosis was small-cell and large-cell neuroendocrine carcinoma with positive ACTH staining. The patient was prescribed mifepristone and received one cycle of chemotherapy. The patient could not tolerate subsequent chemotherapy and died of dyscrasia.

CONCLUSIONS

RM is a rare complication of EAS with insidious onset and atypical clinical manifestations. Serum potassium levels should be vigilantly monitored to avoid RM in EAS.

Recurrence of a neuroendocrine tumor of adrenal origin: a case report with more than a decade follow-up

BACKGROUND

Neuroendocrine tumor (NET) with adrenocorticotropic hormone (ACTH) secretion are very rare. To our knowledge, no follow-up study is published for ACTH-secreting NET, regardless of the primary site, to show second occurrence of tumor after a long follow-up, following resection of primary tumor.

CASE PRESENTATION

Here, we describe a 49-year-old-man with cushingoid feature, drowsiness and quadriparesis came to emergency department at December 2005. Laboratory tests revealed hyperglycemia, metabolic alkalosis, severe hypokalemia, and chemical evidence of an ACTH-dependent hypercortisolism as morning serum cortisol of 57 μg /dL without suppression after 8 mg dexamethasone suppression test, serum ACTH level of 256 pg/mL, and urine free cortisol of > 1000 μg /24 h. Imaging showed only bilateral adrenal hyperplasia, without evidence of pituitary adenoma or ectopic ACTH producing tumors. Importantly, other diagnostic tests for differentiating Cushing disease (CD) from ectopic ACTH producing tumor, such as inferior petrosal sinus sampling (IPSS), corticotropin releasing hormone (CRH) stimulation test, octreotide scan or fluorodeoxyglucose (FDG)-positron emission tomography (PET) scan were not available in our country at that time. Therefore, bilateral adrenalectomy was performed that led to clinical and biochemical remission of hypercortisolism and decreased ACTH level to < 50 pg/mL, findings suggestive of a primary focus of NET in adrenal glands. After 11 years uncomplicated follow up, the ACTH level elevated up to 341 pg/mL and re-evaluation showed a 2 cm nodule in the middle lobe of the right lung. Surgical excision of the pulmonary nodule yielded a carcinoid tumor with positive immunostaining for ACTH; leading to decrease in serum ACTH level to 98 pg/mL. Subsequently after 7 months, serum ACHT levels rose again. More investigation showed multiple lung nodules with metastatic bone lesions accompanied by high serum chromogranin level (2062 ng/mL), and the patient managed as a metastatic NET, with bisphosphonate and somatostatin receptor analogues.

CONCLUSION

This case of surgically-treated NET showing a secondary focus of carcinoid tumor after one decade of disease-free follow-up emphasizes on the importance of long-term follow-up of ACTH-secreting adrenal NET.

Etiology, baseline clinical profile and comorbidities of patients with Cushing's syndrome at a single endocrinological center

PURPOSE

The aim of this study was to compare phenotype of patients with pituitary, adrenal and ectopic CS and identify the differences regarding biochemical parameters, clinical presentations, and comorbidities in CS patients who were diagnosed at the single endocrinological center in Wroclaw.

METHODS

The study population involved 64 patients with CS (53 women and 11 men) diagnosed in Department of Endocrinology, Diabetes and Isotope Therapy in 2000-2018. Patients were divided into three etiologic groups: pituitary dependent-CS (P-CS) (64%), adrenal dependent CS (A-CS) (25%), and CS from an ectopic source (E-CS) (11%).

RESULTS

Percentage of men in the A-CS group was significantly higher than in the other etiologic groups. ACTH, UFC, and cortisol in DST were significantly higher in E-CS group compare to P-CS and A-CS (p < 0.05). Mean potassium level in E-CS group was significantly lower than in P-CS and A-CS (p < 0.05). Median of time elapsed to diagnosis was significantly lower in the E-CS group compared with either the P-CS and the A-CS group (p < 0.01). The most frequently symptoms in CS patients were skin alterations (82.8%), weight gain (81.2%), and hypertension (81.2%).

CONCLUSIONS

The epidemiology of CS is changing toward a growing proportion of A-CS. All patients with E-CS presented a profound hypokalemia. Salient hypokalemia could be a biochemical marker more suggestive for E-CS rather than P-CS. The incidence of diabetes is more frequent in E-CS group than in P-CS and A-CS groups.

Bronchial Carcinoid Tumour as a Rare Cause of Cushing’s Syndrome in Children: A Case Report and Review of Literature

Cushing’s syndrome (CS) is rare in childhood and adolescence. The most common paediatric cause of CS is exogenous administration of glucocorticoids; either topical, inhaled or oral corticosteroids. Endogenous causes can be classified into adrenocorticotropic hormone (ACTH) independent and ACTH dependent causes. Herein, we report our experience of managing a 12 year old girl who presented with features of CS and was found to have an ectopic, ACTH-secreting bronchial carcinoid tumour, which was resected surgically. Our patient was managed successfully by multidisciplinary approach and has recovered from hypertension and Cushing’s habitus. The English language literature was searched from 2019 back, using PubMed, Google and Google Scholar. Keywords used for the search were; “Ectopic ACTH syndrome (EAS) in children”, “bronchial carcinoid in children” and “Cushing’s Syndrome in children”. Children with bronchial carcinoid tumours causing EAS were identified. Case variables such as age, sex, type of carcinoid, investigations, surgery, recurrences and outcome were reviewed. Fourteen cases of paediatric bronchial carcinoid producing ACTH were found with a mean age of 15.8 years and female preponderance. Most of the patients had a right lung lesion and histological appearance was typical of carcinoid tumour. Bronchial carcinoid is extremely rare in children and only 4% are associated with CS. The postoperative treatment of CS is challenging with a high prevalence of hypertension, increased body mass index and visceral fat mass, impaired cognitive function and decreased quality of life. A careful follow up is indispensable for monitoring recurrence of carcinoid and complete remission of CS.

Olfactory neuroblastoma (esthesioneuroblastoma) presenting as ectopic ACTH syndrome: always follow your nose

SUMMARY

ACTH-dependent hypercortisolism is caused by an ectopic ACTH syndrome (EAS) in 20% of cases. We report a rare cause of EAS in a 41-year-old woman, presenting with clinical features of Cushing's syndrome which developed over several months. Biochemical tests revealed hypokalemic metabolic alkalosis and high morning cortisol and ACTH levels. Further testing, including 24-hour urine analysis, late-night saliva and low-dose dexamethasone suppression test, confirmed hypercortisolism. An MRI of the pituitary gland was normal. Inferior petrosal sinus sampling (IPSS) revealed inconsistent results, with a raised basal gradient but no rise after CRH stimulation. Additional PET-CT showed intense metabolic activity in the left nasal vault. Biopsy of this lesion revealed an unsuspected cause of Cushing's syndrome: an olfactory neuroblastoma (ONB) with positive immunostaining for ACTH. Our patient underwent transnasal resection of the tumour mass, followed by adjuvant radiotherapy. Normalisation of cortisol and ACTH levels was seen immediately after surgery. Hydrocortisone substitution was started to prevent withdrawal symptoms. As the hypothalamic-pituitary-axis slowly recovered, daily hydrocortisone doses were tapered and stopped 4 months after surgery. Clinical Cushing's stigmata improved gradually.

LEARNING POINTS

Ectopic ACTH syndrome can originate from tumours outside the thoracoabdominal region, like the sinonasal cavity. The diagnostic accuracy of IPSS is not 100%: both false positives and false negatives may occur and might be due to a sinonasal tumour with ectopic ACTH secretion. Olfactory neuroblastoma (syn. esthesioneuroblastoma), named because of its sensory (olfactory) and neuroectodermal origin in the upper nasal cavity, is a rare malignant neoplasm. It should not be confused with neuroblastoma, a tumour of the sympathetic nervous system typically occurring in children. If one criticises MRI of the pituitary gland because of ACTH-dependent hypercortisolism, one should take a close look at the sinonasal field as well.

[Ectopia of the adrenal]

Ectopia of nodular adrenocortical tissue is very frequently found in the periadrenal region. It corresponds to accessory adrenal tissue and is a normal variant. Ectopia in more distant regions are found in inner male or female genitalia. Strong long-lasting hyperstimultions induce hyperplasia and simulate true tumors ("adrenal rest tumors"). Real autonomic tumors from ectopic adrenal tissue with or without hyperfunction are rare. Ectopia of adrenomedullary tissue are nearly exclusively found in the surroundings of normal medulla. Ectopia in the adrenals corresponds almost exclusively with thyroid tissue. Ectopic secretion of hormones, mostly ACTH, can be found in pheochromocytomas and induces hyperfunction (Cushing's syndrome).

Molecular analysis and literature-based hypothesis of an immunonegative prostate small cell carcinoma causing ectopic ACTH syndrome

Ectopic ACTH syndrome (EAS) due to a prostate small cell carcinoma (SCC) is very rare with only 26 cases reported to date and has a poor prognosis. We here describe another case of this disorder that was clinically typical based on prior reports as it showed hypercortisolemia and severe hypokalemia with multiple metastasis. However, our current case of prostate SCC causing EAS is the first to display negative immunostaining for ACTH despite detectable POMC mRNA expression in the primary lesion. ACTH immunonegativity is thought to be associated with a more aggressive disease course and a poorer prognosis although there are few studies of the underlying mechanisms. We explored two possibilities for this finding in our current patient: aberrant POMC processing prevented immunodetection with an anti-ACTH antibody; and the ACTH content per cell was below the threshold for immunodetection due to its rapid secretion or low synthesis. The aberrant processing theory was thought to be less likely because of immunonegative findings even using anti-POMC/ACTH antibodies. As the plasma ACTH levels in our patient were comparable with those reported for previous immunopositive prostate EAS cases, we speculated that the depletion of ACTH may be caused not only by rapid secretion but also by low production levels as a sign of de-differentiation. De-differentiation may therefore explain the mechanism underlying the negative correlation between immunoreactivity for ACTH in EAS and disease aggressiveness. We believe that our present findings will be of use in future prospective studies aimed at confirming the mechanism of immunonegativity.

A unique case of ectopic Cushing's syndrome from a thymic neuroendocrine carcinoma

Ectopic adrenocorticotropic hormone (ACTH) production leading to ectopic ACTH syndrome accounts for a small proportion of all Cushing's syndrome (CS) cases. Thymic neuroendocrine tumors are rare neoplasms that may secrete ACTH leading to rapid development of hypercortisolism causing electrolyte and metabolic abnormalities, uncontrolled hypertension and an increased risk for opportunistic infections. We present a unique case of a patient who presented with a mediastinal mass, revealed to be an ACTH-secreting thymic neuroendocrine tumor (NET) causing ectopic CS. As the diagnosis of CS from ectopic ACTH syndrome (EAS) remains challenging, we emphasize the necessity for high clinical suspicion in the appropriate setting, concordance between biochemical, imaging and pathology findings, along with continued vigilant monitoring for recurrence after definitive treatment. Learning points: Functional thymic neuroendocrine tumors are exceedingly rare. Ectopic Cushing's syndrome secondary to thymic neuroendocrine tumors secreting ACTH present with features of hypercortisolism including electrolyte and metabolic abnormalities, uncontrolled hypertension and hyperglycemia, and opportunistic infections. The ability to undergo surgery and completeness of resection are the strongest prognostic factors for improved overall survival; however, the recurrence rate remains high. A high degree of initial clinical suspicion followed by vigilant monitoring is required for patients with this challenging disease.

Ectopic adrenocorticotropic hormone syndrome associated with olfactory neuroblastoma: acquirement of adrenocorticotropic hormone expression during disease course as shown by serial immunohistochemistry examinations

Ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is a condition of endogenous hypercortisolism sustained by an extrapituitary ACTH-secreting tumor. Olfactory neuroblastoma (ONB) is a rare malignant neoplasm of the sinonasal tract and is derived from the olfactory epithelium. Because the paranasal sinus is not a common site of EAS, the development of ONB in patients with EAS is rare. We herein report the first known case of ONB with acquirement of ACTH production during the clinical course as proven by immunohistochemistry. A 50-year-old man diagnosed with ONB was referred to our department in July 2015 because of hypokalemia, hyperglycemia, decreased eosinophil and granulocyte counts, and elevated serum levels of ACTH and cortisol. Although two previous ONB biopsy specimens (2011 and 2014) showed no ACTH immunoreactivity, a newly obtained specimen in August 2015 clearly showed ACTH immunoreactivity. This is the first case of ectopic ACTH syndrome associated with an ONB that acquired the ability to express ACTH during its clinical course as shown by serial immunohistochemical examinations.

A case of ectopic ACTH syndrome due to DDAVP-sensitive but V1b receptor-negative bronchial typical carcinoid with lymphatic metastasis and plasma ProGRP elevation

Ectopic ACTH syndrome (EAS) is a potentially fatal endocrine disease that results from a variety of neuroendocrine tumors (NETs), such as small cell lung cancer (SCLC) and bronchial typical carcinoid. Typical carcinoid is usually slow growing, not associated with plasma progastrin releasing peptide (ProGRP) elevation. Here, we report a 47-year-old female smoker with progressive typical carcinoid and plasma ProGRP elevation. Several types of Cushingoid features were found on physical examination. In addition, laboratory examination showed elevated plasma ACTH and serum cortisol levels. These findings indicated ACTH-dependent Cushing's syndrome. Moreover, the serum cortisol level was not suppressed by overnight high-dose dexamethasone treatment, suggesting the presence of an extra-pituitary tumor. Contrast-enhanced brain MRI revealed no pituitary adenoma, which also supported the idea that EAS occurred in the present case. Strikingly, chest computed tomographic (CT) scan showed a single 18-mm peripheral nodule in the right middle lobe of the lung. Tumor marker analysis revealed an elevation in plasma ProGRP. These data suggested a possibility that SCLC secreted ACTH and caused EAS in this patient. Of note, the plasma ACTH level was increased (1.7 fold) in l-desamino-8-D-arginine vasopressin (DDAVP) test, also suggesting the specific clinical feature in this case. After additional imaging examinations, we performed surgical resection with the suspicion of limited SCLC. As a result, pathological examination revealed a vasopressin receptor Ib (V1b) receptor-negative bronchial typical carcinoid with ACTH production and mediastinal lymphatic metastasis. In summary, we present a case of EAS caused by progressive bronchial typical carcinoid with plasma ProGRP elevation. We propose a novel subtype of lung typical carcinoid.

Metyrapone-responsive ectopic ACTH-secreting pheochromocytoma with a vicious cycle via a glucocorticoid-driven positive-feedback mechanism

In ectopic ACTH-secreting pheochromocytoma, combined ACTH-driven hypercortisolemia and hypercatecholaminemia are serious conditions, which can be fatal if not diagnosed and managed appropriately, especially when glucocorticoid-driven positive feedback is suggested with a high ACTH/cortisol ratio. A 46-year-old man presented with headache, rapid weight loss, hyperhidrosis, severe hypertension and hyperglycemia without typical Cushingoid appearance. Endocrinological examinations demonstrated elevated plasma and urine catecholamines, serum cortisol and plasma ACTH. Moreover, his ACTH/cortisol ratio and catecholamine levels were extremely high, suggesting catecholamine-dominant ACTH-secreting pheochromocytoma. Computed tomography revealed a large right adrenal tumor. ¹⁸F-FDG positron emission tomography showed uptake in the area of the adrenal tumor, while ¹²³I-metaiodobenzylguanidine scintigraphy showed no accumulation. His plasma ACTH level paradoxically became elevated after a dexamethasone suppression test. After metyrapone administration, not only serum cortisol but also plasma ACTH levels were exponentially decreased almost in parallel, suggesting a glucocorticoid-driven positive-feedback regulation in this rapidly exacerbated ectopic ACTH-producing pheochromocytoma. Interestingly enough, plasma catecholamine levels were also decreased by metyrapone, although they remained extremely high. He became severely dehydrated due to hypoadrenalism requiring hydrocortisone supplementation. His clinical signs and symptoms were improved, and right adrenalectomy was performed uneventfully, resulting in complete remission of pheochromocytoma and Cushing's syndrome. A glucocorticoid-driven positive-feedback regulation in this ectopic ACTH-secreting pheochromocytoma created a vicious cycle with rapid exacerbation of both hypercortisolemia and hypercatecholaminemia with extremely elevated plasma ACTH level. Metyrapone was clinically effective to stop this vicious cycle; nonetheless, great care must be taken to avoid hypoadrenalism especially when hypercatecholaminemia remained.

Sphenoid sinus carcinoid tumour causing ectopic ACTH syndrome

A thirty-eight year old patient presented with a gradual increase in weight and Cushingoid facies of two years duration. He also had orbital congestion, with puffy eyelids and corkscrew conjunctival vessels, associated with painful eye movements. An endocrine evaluation revealed raised cortisol and ACTH. Head imaging was performed which showed an enhancing tumour arising from the sphenoid sinus, with osseous erosion of the sphenoid sinus, extending to the nasopharynx, sellar and a small amount extending intracranially. He underwent an endoscopic endonasal resection of the tumour and histology revealed a low-grade carcinoid tumour with ACTH staining. The patient also underwent radiotherapy for the intracranial extension. He is currently in his fourth year of follow-up and imaging has showed a small, stable intracranial remnant. His anterior pituitary hormonal profile remains normal.

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.

Primary intracranial neuroendocrine tumor: two case reports

BACKGROUND

Neuroendocrine tumor originates from the diffuse neuroendocrine system. Intracranial originating is lower to 0.74 %.

CASE PRESENTATION

We present two cases of primary intracranial neuroendocrine tumor A 39-year-old woman was admitted with headache, fever, polydipsia and polyuria. Biochemical and endocrinological results showed hyponatremia, hypothyroidism and hypopituitarism. MRI scans demonstrated an obviouslyenhancing lesion in seller and superseller area. Then a gross removal of tumor was achieved during the single nostril transsphenoidal approach surgery. Pathological diagnosis was high-grade small-cell neuroendocrine tumor. A 40-year-old woman presented with multiple symptoms and neurological deficit. Neuroimaging results demonstrated a huge obviously-enhancing tumor in anterior cranial fossa. Biochemical and hormone findings revealed hypokalemia, high glucose and hypercortisolemia. The intracranial surgery achieved a gross removal through a right frontal craniotomy. Pathological diagnosis was low-grade small-cell neuroendocrine tumor with immuno-negativity for ACTH.

CONCLUSION

The mechanism, diagnosis, and treatment of neuroendocrine tumor are still challenging.

Single-Session CT-Guided Percutaneous Microwave Ablation of Bilateral Adrenal Gland Hyperplasia Due to Ectopic ACTH Syndrome

Bilateral adrenalectomy is currently the only available treatment for adrenocorticotropic hormone (ACTH)-dependent Cushing's syndrome (ectopic ACTH syndrome) that is refractory to pharmacologic therapy. We describe two patients with refractory ectopic ACTH syndrome who were treated with CT-guided percutaneous microwave ablation of both hyperplastic adrenal glands in a single session: O ne was not a surgical candidate, and the other had undergone unsuccessful surgery. Following the procedure, both patients achieved substantial decreases in serum cortisol, symptomatic improvement, and decreased anti-hypertensive medication requirements.

Periodic hypokalemia associated with cyclic Cushing's syndrome

A 69-year-old woman presented with periodic hypertension, edema, and hypokalemia that occurred within an interval of a few weeks. Her laboratory test values showed autonomously elevated plasma adrenocorticotropic hormone (ACTH) and cortisol concentrations. The patient's Cushingoid features were not evident on first admission. Several weeks later, in spite of constant oral potassium supplementation, severe hypokalemia recurred with Cushingoid features and worsening symptoms of leg edema and pigmentation, which spontaneously disappeared within a few days. Her periodic symptoms occurred in parallel with fluctuations of plasma ACTH and cortisol concentrations. A series of endocrinological and pituitary imaging findings led to a tentative diagnosis of cyclic Cushing's syndrome caused by ectopic ACTH secretion. However, chest and abdominal computed tomography did not reveal any candidate lesion. The patient's periodic hypercortisolemia and symptoms were well controlled after treatment with metyrapone plus dexamethasone. This is a very rare case of periodic hypokalemia and hypertension caused by cyclic Cushing's syndrome.

Cushing's Syndrome: An Unusual Presentation of Olfactory Neuroblastoma

A 48-year-old man presented with symptoms consistent with Cushing's syndrome. Subsequent laboratory studies revealed markedly elevated adrenocorticotropic (ACTH) and cortisol levels, as well as a hypoklemic metabolic alkalosis. A pituitary MRI was performed, which revealed a normal pituitary; however, a large mass was seen centered in the ethmoid and paranasal sinuses with a significant amount of extension into surrounding structures. A biopsy was performed and pathology of the specimen was consistent with esthesioneuroblastoma. Immunohistochemical staining further defined the tumor as an ACTH-secreting esthesioneuroblastoma. After total resection of the mass and further treatment with adjuvant radiation therapy, the patient's symtoms completely resolved and the ACTH and cortisol levels were also greatly reduced. This case demonstrates the successful diagnosis and treatment of a rare neoplasm. Ectopic ACTH syndrome due to esthesioneuroblastoma is extremely uncommon with only five other cases being discussed in the literature.