Ectopic CRH/ACTH-Co-Secreting Neuroendocrine Tumors Leading to Cushing’s Disease

Posted on March 17, 2025 by MaryO

Abstract

Adrenocorticotropic hormone (ACTH) and corticotropin-releasing hormone (CRH) are essential regulators of cortisol production within the hypothalamic-pituitary-adrenal (HPA) axis. Elevated cortisol levels, resulting from excessive ACTH, can lead to Cushing’s syndrome, a condition with significant morbidity. Neuroendocrine tumors (NETs) can ectopically produce both ACTH and CRH, contributing to this syndrome. This review discusses the pathophysiology, types, clinical presentation, diagnosis, and management of these tumors. Emphasis is placed on the importance of identifying dual CRH/ACTH secretion, which complicates diagnosis and necessitates tailored therapeutic strategies. Furthermore, the review highlights the prognosis, common complications, and future directions for research in this area.

We report the case of a 53-year-old female patient who presented with severe Cushing’s syndrome and was diagnosed with ectopic ACTH syndrome. Despite initial indications pointing towards pituitary-dependent hypercortisolism, further investigations revealed the presence of a highly differentiated atypically located tumor in the upper lobe of the left lung, adjacent to the mediastinum. Immunohistochemistry of the tumor tissue demonstrated not only ACTH but also CRH and CRH-R1 expression. The simultaneous expression of these molecules supports the hypothesis of the presence of a positive endocrine feedback loop within the NET, in which the release of CRH stimulates the expression of ACTH via binding to CRH-R1. This case report highlights the challenges in diagnosing and managing ectopic ACTH syndrome, emphasizing the importance of a comprehensive diagnostic approach to identify secondary factors impacting cortisol production, such as CRH production and other contributing neuroendocrine mechanisms.

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Ectopic Cushing’s Syndrome From a Corticotropin-Releasing Hormone-Secreting Medullary Thyroid Carcinoma: a Rare Pitfall af Inferior Petrosal Sinus Sampling

Posted on October 27, 2023 by MaryO

Abstract

Summary

This case report describes a rare presentation of ectopic Cushing’s syndrome (CS) due to ectopic corticotropin-releasing hormone (CRH) production from a medullary thyroid carcinoma (MTC).

The patient, a 69-year-old man, presented with symptoms of muscle weakness, facial plethora, and easy bruising.

An inferior petrosal sinus sampling test (IPSS) demonstrated pituitary adrenocorticotrophic hormone (ACTH) secretion, but a whole-body somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) revealed enhanced uptake in the right thyroid lobe which, in addition to a grossly elevated serum calcitonin level, was indicative of an MTC. A 18F-DOPA PET/CT scan supported the diagnosis, and histology confirmed the presence of MTC with perinodal growth and regional lymph node metastasis.

On immunohistochemical analysis, the tumor cell stained positively for calcitonin and CRH but negatively for ACTH. Distinctly elevated plasma CRH levels were documented. The patient therefore underwent thyroidectomy and bilateral adrenalectomy.

This case shows that CS caused by ectopic CRH secretion may masquerade as CS due to a false positive IPSS test. It also highlights the importance of considering rare causes of CS when diagnostic test results are ambiguous.

Learning points

  • Medullary thyroid carcinoma may secrete CRH and cause ectopic CS.
  • Ectopic CRH secretion entails a rare pitfall of inferior petrosal sinus sampling yielding a false positive test.
  • Plasma CRH measurements can be useful in selected cases.

Background

The common denominator of Cushing’s syndrome (CS) is autonomous hypersecretion of cortisol (1) and it is subdivided into ACTH-dependent and ACTH-independent causes. The majority of CS cases are ACTH-dependent (80–85%) with a pituitary corticotroph tumor as the most prevalent cause (Cushing’s disease), and less frequently an ectopic ACTH-producing tumor (2). The gold standard method to ascertain the source of ACTH secretion in CS patients is inferior petrosal sinus sampling (IPSS) with measurement of plasma ACTH levels in response to systemic corticotropin-releasing hormone (CRH) stimulation (3). The IPSS has a very high sensitivity and specificity of 88–100% and 67–100%, respectively (4), but pitfalls do exist, including the rare ectopic CRH-producing tumor, which may yield a false positive test result (3). Here, we describe a very rare case masquerading as CS including a positive IPSS test.

Case presentation

A 69-year-old man presented at a local hospital with a 6-month history of progressive fatigue, muscle weakness and wasting, easy bruising, facial plethora, and fluid retention. His serum potassium level was 2.6 mmol/L (reference range: 3.5–4.2 mmol/L) without a history of diuretics use. His previous medical history included spinal stenosis, benign prostatic hyperplasia, and hypertension. An electromyography showed no sign of polyneuropathy and an echocardiography showed no signs of heart failure with an ejection fraction of 55%. MRI of the spine revealed multiple compression fractures, and the patient underwent spinal fusion and decompression surgery; during this admission he was diagnosed with type 2 diabetes (HbA1c: 55 mmol/mol). After spine surgery, the patient developed a pulmonary embolism and initiated treatment with rivaroxaban.

Establishing the diagnosis of ACTH-dependent CS

Six months after his spine surgery, the patient was referred to the regional department of endocrinology for osteoporosis management. Blood tests revealed a low serum testosterone level with non-elevated luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels (Table 1). An overnight 1 mg dexamethasone suppression test was positive with a morning cortisol level of 254 nmol/L and three consecutive 24-h urinary cortisol levels were markedly elevated with mean level of ≈600 nmol/24 h (reference range: 12–150 nmol/24 h). A single plasma ACTH was 37 ng/L (Table 1).

Table 1Baseline endocrine assessment.

Parameters Patient’s values Reference range
ACTH, ng/L 37 7–64
UFC, nmol/day 588 12–150
Urinary cortisol, nmol/L 600 171–536
OD, nmol/L 254 <50
Free testosterone, nmol/L 0.061 0.17–0.59
HbA1c, mmol/mol 55 <48
FSH, IU/L 7.4 1.2–15.8
LH, IU/L 2.2 1.7–8.6

ACTH, adrenocorticotropin; FSH, follicle-stimulating hormone; IU, international units; LH, luteinizing hormone; OD, plasma cortisol levels after a 1 mg overnight dexamethasone suppression test; UFC, urine free cortisol hormone.

Differential diagnostic tests

The patient was referred to a tertiary center for further examinations. Ketoconazole treatment was started to alleviate the consequences of hypercortisolism. A pituitary MRI revealed an intrasellar microtumor with a maximal diameter of 6 mm and an IPSS was ordered. A whole-body somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) was also performed to evaluate the presence of a potential neuroendocrine tumor. This revealed multiple areas of enhanced uptake including the right thyroid lobe and cervical lymph nodes in the neck (with CT correlates), as well as in the duodenum (with no CT correlate). Concomitantly, a grossly elevated serum calcitonin level of 528 pmol/L (reference range <2.79 pmol/L) was measured.

Subsequently, the IPSS revealed pituitary ACTH secretion with a central-to-peripheral ACTH ratio >3 (Table 2). The right petrosal sinus was not successfully catheterized; thus, lateralization could not be determined.

To corroborate the diagnosis MTC, a 18F-DOPA PET/CT scan (FDOPA) was performed (5), which showed pathologically enhanced uptake in the right thyroid lobe and regional lymph nodes (Fig. 1). An ultrasound-guided core needle biopsy from the thyroid nodule was inconclusive; however, the patient underwent total thyroidectomy and regional lymph node resection, from which histology confirmed the diagnosis of disseminated MTC. Standard replacement with levothyroxine, calcium, and vitamin D was initiated. A blood sample was collected, and genomic DNA was extracted. The DNA analysis for RET germline mutation was negative.

Figure 1View Full Size
Figure 1
18F-DOPA PET/CT scan with pathologically enhanced uptake in the right thyroid lobe (large blue arrow on the left side) and regional lymph nodes (small blue arrows).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 3; 10.1530/EDM-23-0057

Table 2Results from the inferior petrosal sinus sampling.*

Time (min) Left IPSS Peripheral L/P
-5 42 36 1.2
-1 116 33 3.5
2 120 32 3.8
5 209 28 7.5
7 180 43 4.2
10 529 34 15.6
15 431 37 11.6

*Data represents ACTH levels in ng/L. IPSS Inferior petrosal sampling ACTH Adrenocorticotropin hormone CRH Corticotropin-releasing hormone, L/P Ratio of left (L) inferior petrosal sinus to peripheral venous ACTH concentrations.

Pathology

Total thyroidectomy and bilateral cervical lymph node dissection (level six and seven) were performed. Macroscopic evaluation of the right thyroid lobe revealed a 24 mm, irregular solid yellow tumor. Microscopically the tumor showed an infiltrating architecture with pseudofollicles and confluent solid areas. Calcification was prominent, but no amyloid deposition was seen. The tumor cells were pleomorphic with irregular nuclei and heterogenic chromatin structure. No mitotic activity or necrosis was observed. On immunohistochemical analysis, the tumor cells expressed thyroid transcription factor 1 and stained strongly for carcinoembryonic antigen and calcitonin; tumor cells were focally positive for cytokeratin 19. The tumor was completely negative for ACTH, thyroid peroxidase, and the Hector Battifora mesothelial-1 antigen. Further analysis revealed positive immunostaining for CRH (Fig. 2). The Ki-67 index was very low (0–1%), indicating a low cellular proliferation. Molecular testing for somatic RET mutation was not performed.

Figure 2View Full Size
Figure 2
Histopathological findings and immunohistochemical studies of MTC. (A) Microscopic features of medullary thyroid carcinoma. (B) Polygonal tumor cells (hematoxylin and eosin, ×40). (C) Tumor cells stain for calcitonin (×20). (D) Immunohistochemical stain (×400) for CRH showing cells being positive (brown). (E) Pituitary tissue from healthy control staining positive for ACTH in comparison to (F) ACTH-negative cells MTC tissue from the patient (×20).

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 3; 10.1530/EDM-23-0057

No malignancy was found in the left thyroid lobe and there was no evidence of C-cell hyperplasia. Regional lymph node metastasis was found in 13 out of 15 nodes with extranodal extension.

Outcome and follow-up

Follow-up

Serum calcitonin levels declined after neck surgery but remained grossly elevated (118 pmol/L 3 weeks post surgery) and cortisol levels remained high. Ketoconazole treatment was poorly tolerated and not sufficiently effective. Plasma levels of CRH were measured by a competitive-ELISA kit (EKX-KIZI6R-96 Nordic BioSite), according to the instructions provided by the manufacturer. The intra- and interassay %CV (coefficient of variability) were below 8% and 10%, respectively, and the assay sensitivity was 1.4 pg/mL. The plasma CRH was distinctly elevated compared to in-house healthy controls both before and after thyroid surgery (Fig. 3).

Figure 3View Full Size
Figure 3
Plasma CRH levels before and after total thyroidectomy compared to three healthy controls.

Citation: Endocrinology, Diabetes & Metabolism Case Reports 2023, 3; 10.1530/EDM-23-0057

The patient subsequently underwent uneventful bilateral laparoscopic adrenalectomy followed by standard replacement therapy with hydrocortisone and fludrocortisone. The symptoms and signs of his CS gradually subsided. Pathology revealed bilateral cortical hyperplasia as expected.

The patient continues follow-up at the Department of Oncology and the Department of Endocrinology and Internal Medicine. At 13-month follow-up, 68Ga-DOTATOC shows residual disease with pathologically enhanced uptake in two lymph nodes, whereas the previously described focal DOTATOC uptake in the duodenum was less pronounced (still no CT correlate). Serum calcitonin was 93 pmol/L at the 13-month follow-up.

Discussion

Diagnostic challenges remain in the distinction between pituitary and ectopic ACTH-dependent CS, and several diagnostic tools are used in combination, none of which is infallible, including IPSS (6). Our case and others illustrate that ectopic CRH secretion may yield a false positive IPSS test result (3). Measurement of circulating CRH levels is relevant if an ectopic CRH producing tumor is suspected, but the assay is not routinely available in clinical practice (Lynnette K Nieman M. Measurement of ACTH, CRH, and other hypothalamic and pituitary peptides https://www.uptodate.com/contents/measurement-of-acth-crh-and-other-hypothalamic-and-pituitary-peptides: UpToDate; 2019). In our case, the presence of elevated plasma CRH levels after thyroidectomy strengthened the indication for bilateral adrenalectomy.

The most common neoplasm causing ectopic CS is small-cell lung cancer, whereas MTC accounts for 2–8% of ectopic cases (7). The development of CS in relation to MTC is generally associated with advanced disease and poor prognosis of an otherwise relatively indolent cancer (8), and the clinical progression of CS is usually rapid, why an early recognition and rapid control of hypercortisolemia and MTC is necessary to decrease morbidity and mortality (7, 9). Our case does have residual disease; however, he remains progression-free with stable and relatively low calcitonin levels within 1-year follow-up.

Only a very limited number of cases of ectopic tumors with either combined ACTH and CRH secretion or isolated CRH secretion have been reported, with ectopic CRH secretion accounting for less than 1% of CS (9).

An ACTH- or CRH-producing tumor can be difficult to localize and may include gastric ACTH/CRH-secreting neuroendocrine tumors (9). In our case, the 68Ga-DOTATOC identified a possible duodenal site, in addition to the MTC, but an upper gastrointestinal endoscopy revealed no pathological findings and there was no CT correlate. Thus, we concluded that the most likely and sole source of ectopic CRH was the MTC and its metastases.

To our knowledge, no official guidelines for managing ectopic ACTH-dependent CS have been established. In a recent publication by Alba et al. (10), the authors demonstrated a clinical algorithm (The Mount Sinai Clinical Pathway, MSCP) and recommendation for the management of CS due to ectopic ACTH secretion.

Essentially, our approach in this particular case followed these recommendations, including source location by CT and 68Ga-DOTATATE PET/CT imaging, acute management with ketoconazole, and finally, bilateral adrenalectomy as curative MTC surgery was not possible. In retrospect, performance of the IPSS could be questioned in view of the MTC diagnosis. In real time, however, a pituitary MRI performed early in the diagnostic process revealed a microadenoma, which prompted the IPSS. In parallel, a somatostatin receptor scintigraphy (68Ga-DOTATOC PET/CT) was also done, which raised the suspicion of an MTC.

Conclusion

We report a very rare case of an ectopic CS caused by a CRH-secreting MTC. Although IPSS has stood the test of time in the differential diagnosis of ACTH-dependent CS, this case illustrates a rare pitfall.

Declaration of interest

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Funding

This research did not receive any specific grant from any funding agency in the public, commercial, or not-for-profit sector.

Patient consent

Written informed consent for publication of their clinical details was obtained from the patient.

Author contribution statement

JOJ and MJO are the physicians responsible for the patient. LR performed the thyroidectomy and bilateral adrenalectomy. SHM and SLA assessed and reassessed the histopathology and the immunohistochemical analysis. MB measured plasma CRH. VM, JOJ, and MJO drafted the manuscript. All authors contributed to critical revision of the manuscript.

References

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Patients Undergoing Adrenalectomy Should Receive Steroid Substitutive Therapy

Posted on December 14, 2017 by MaryO

All patients who undergo removal of one adrenal gland due to Cushing’s syndrome (CS) or adrenal incidentaloma (AI, adrenal tumors discovered incidentally) should receive a steroid substitutive therapy, a new study shows.

The study, “Predictability of hypoadrenalism occurrence and duration after adrenalectomy for ACTH‐independent hypercortisolism,” was published in the Journal of Endocrinological Investigation.

CS is a rare disease, but subclinical hypercortisolism, an asymptomatic condition characterized by mild cortisol excess, has a much higher prevalence. In fact, subclinical hypercortisolism, is present in up to 20 percent of patients with AI.

The hypothalamic-pituitary-adrenal axis (HPA axis) is composed of the hypothalamus, which releases corticotropin-releasing hormone (CRH) that acts on the pituitary to release adrenocorticotropic hormone (ACTH), that in turn acts on the adrenal gland to release cortisol.

To avoid excess cortisol production, high cortisol levels tell the hypothalamus and the pituitary to stop producing CRH and ACTH, respectively. Therefore, as CS and AI are characterized by high levels of cortisol, there is suppression of the HPA axis.

As the adrenal gland is responsible for the production of cortisol, patients might need steroid substitutive therapy after surgical removal of AI. Indeed, because of HPA axis suppression, some patients have low cortisol levels after such surgeries – clinically known as post-surgical hypocortisolism (PSH), which can be damaging to the patient.

While some researchers suggest that steroid replacement therapy should be given only to some patients, others recommend it should be given to all who undergo adrenalectomy (surgical removal of the adrenal gland).

Some studies have shown that the severity of hypercortisolism, as well as the degree of HPA axis suppression and treatment with ketoconazole pre-surgery in CS patients, are associated with a longer duration of PSH.

Until now, however, there have been only a few studies to guide in predicting the occurrence and duration of PSH. Therefore, researchers conducted a study to determine whether HPA axis activity, determined by levels of ACTH and cortisol, could predict the occurrence and duration of PSH in patients who undergo an adrenalectomy.

Researchers studied 80 patients who underwent adrenalectomy for either CS or AI. Prior to the surgery, researchers measured levels of ACTH, urinary free cortisol (UFC), and serum cortisol after 1 mg dexamethasone suppression test (1 mg-DST).

After the surgery, all patients were placed on steroid replacement therapy and PSH was determined after two months. For those with PSH, levels of cortisol were determined every six months for at least four years.

Results showed that PSH occurred in 82.4 percent of CS patients and 46 percent of AI patients. PSH lasted for longer than 18 months in 50 percent of CS and 30 percent of AI patients. Furthermore, it lasted longer than 36 months for 35.7 percent of CS patients.

In all patients, PSH was predicted by pre-surgery cortisol levels after the 1 mg-DST, but with less than 70 percent accuracy.

In AI patients, a shorter-than-12-month duration of PSH was not predicted by any HPA parameter, but was significantly predicted by an absence of pre-surgery diagnosis of subclinical hypercortisolism.

So, this study did not find any parameters that could significantly predict with high sensitivity and specificity the development or duration of PSH in all patients undergoing adrenalectomy.

Consequently, the authors concluded that “the PSH occurrence and its duration are hardly predictable before surgery. All patients undergoing unilateral adrenalectomy should receive a steroid substitutive therapy.”

From https://cushingsdiseasenews.com/2017/12/08/therapy-cushings-patients-adrenalectomy/

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Desmopressin is Promising Alternative in Diagnosing Cushing’s Disease

Posted on November 15, 2017 by MaryO

Bilateral inferior petrosal sinus sampling (IPSS) — a procedure that uses desmopressin to determine levels of ACTH hormone from veins that drain from the pituitary gland, is a sensitive way to diagnose patients with Cushing’s disease and find tumors, a Chinese study shows.

The study, “Tumour Lateralization in Cushing’s disease by Inferior Petrosal Sinus Sampling with desmopressin,” appeared in the journal Clinical Endocrinology.

Cushing’s disease is characterized by excessive production of the adrenocorticotropin hormone (ACTH) caused by a tumor in the pituitary gland. ACTH is the hormone that causes the adrenal glands to produce cortisol.

Currently, pituitary imaging is insufficient to confirm a Cushing’s diagnosis. This is because 70 percent of pituitary adenomas in Cushing’s are microadenomas, which are physically very small. As a result, 40 percent of Cushing’s patients are reported as being healthy.

This means that a Cushing’s diagnosis requires a combination of techniques including clinical symptoms, imaging methods and endocrinological assays that include measures of serum cortisol and ACTH levels.

IPSS determines ACTH levels from veins that drain from the pituitary gland. ACTH levels are then compared to ACTH levels in blood. Higher levels in the pituitary gland indicate a pituitary tumor.

IPSS can also be used to determine tumor lateralization, which refers to which side of the pituitary gland the tumor is located on. The test is 69 percent accurate.

Doctors administer IPSS along with corticotropin-releasing hormone (CRH) stimulation. IPSS with CRH is considered the gold standard for preoperative diagnosis of Cushing’s, with a diagnostic sensitivity (or true positive rate) of 95 percent and specificity (or true negative rate) of 90 to 95 percent. Unfortunately, the high cost and limited availability of CRH make it impractical for many patients.

Desmopressin has been used to replace CRH to stimulate ACTH secretion for IPSS, and prior studies have shown that desmopressin’s sensitivity is comparable to that of CRH.

Researchers at Peking Union Medical College in Beijing conducted a retrospective analysis of their experience using desmopressin-stimulated IPSS to determine its diagnostic value for Cushing’s and its predictive value for tumor lateralization.

Researchers analyzed 91 Cushing’s patients who either had negative findings on the MRI imaging of the pituitary or negative high-dose dexamethasone suppression tests, which is another method of evaluation. All patients underwent IPSS with desmopressin, followed by pituitary surgery to extract the tumor.

Of the 91 patients tested, 90 patients had confirmed Cushing’s. And of these, 89 had positive IPSS findings, which led to a sensitivity of 98.9 percent for this test. One patient out of 91 who did not have Cushing’s also underwent this test, which led to a negative IPSS result and a specificity of 100 percent.

Researchers also determined tumor lateralization in patients who were ultimately diagnosed with Cushing’s and underwent surgery. Results of the IPSS showed a 72.5 percent concordance between the results from the IPSS and the surgery.

Therefore, IPSS with desmopressin is a comparable approach to IPSS with CRH for the diagnosis of Cushing’s. It also demonstrates moderate accuracy in determining the location of tumors.

“Like many medical centers in China, we currently have no supply of CRH, while desmopressin is readily available,” researchers concluded. “Moreover, desmopressin is cheaper than CRH. As our data and other studies indicate, IPSS with desmopressin yielded comparable outcomes to IPSS with CRH. Therefore, desmopressin-stimulated IPSS might serve as a possible alternative to CRH-stimulated IPSS.”

From https://cushingsdiseasenews.com/2017/11/14/ipss-desmopressin-alternative-method-diagnosis-cushings-disease/

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Rare neuroendocrine tumours may be misdiagnosed as Cushing’s disease

Posted on October 31, 2014 by MaryO

By Eleanor McDermid, Senior medwireNews Reporter

Ectopic tumours secreting corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) are very rare in children and can result in a misdiagnosis of Cushing’s disease (CD), say researchers.

Three of the patients in the reported case series had pituitary hyperplasia and underwent transsphenoidal surgery for apparent CD before the tumour that was actually causing their symptoms was located. The hyperplasia was probably caused by release of CRH from the ectopic tumour, which stimulated the pituitary gland, giving the impression of an ACTH-secreting pituitary adenoma, explain Maya Lodish (National Institutes of Health, Bethesda, Maryland, USA) and study co-authors.

These three patients were part of a series of seven, which Lodish et al describe as “a relatively large number of patients, considering the infrequency of this disease.”

The patients were aged between 1.8 and 21.3 years. Three had neuroendocrine tumours located in the pancreas ranging in size from 1.4 to 7.0 cm, two had thymic carcinoids ranging from 6.0 mm to 11.5 cm, one patient had a 12.0 cm tumour in the liver and one had a 1.3 cm bronchogenic carcinoid tumour of the right pulmonary lobe.

Four of the patients had metastatic disease and, during up to 57 months of follow-up, three died of metastatic disease or associated complications and two patients had recurrent disease.

“Our series demonstrates that these are aggressive tumors with a high mortality rate,” write the researchers in the Journal of Clinical Endocrinology & Metabolism. “It is important to follow the appropriate work up, regarding both biochemical and imaging tests, which can lead to the correct diagnosis and to the most beneficial therapeutic approach.”

The team found the CRH stimulation test to be helpful, noting, for example, that none of the patients had a rise in cortisol that was consistent with CD, with all patients showing smaller responses ranging from 2% to 15%. Likewise, just one patient had an ACTH rise higher than 35% on CRH administration, and four patients had a “flat” response, which has previously been associated with ectopic neuroendocrine tumours.

Of note, six patients had normal or high plasma CRH levels, despite all having high cortisol levels, which would be expected to result in undetectable plasma CRH due to negative feedback, implying another source of CRH production. Five patients had blunted diurnal variation of both cortisol and ACTH levels consistent with Cushing’s syndrome.

The patients also underwent a variety of imaging procedures to identify the source of ACTH/CRH production, some of which, such as octreotide scans, are specialist and not available in most hospitals, the researchers note, potentially contributing to inappropriate diagnosis and management.

From http://www.news-medical.net/news/20141030/Rare-neuroendocrine-tumours-may-be-misdiagnosed-as-Cushinge28099s-disease.aspx

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