Cushing’s Syndrome caused by ACTH Precursors Secreted from a Pancreatic Yolk Sac Tumor in an Adult

Here, we report the first adult case of pancreatic yolk sac tumor with ectopic adrenocorticotropic hormone (ACTH) syndrome. The patient was a 27-year-old woman presenting with abdominal distension, Cushingoid features, and hyperpigmentation. Endogenous Cushing’s syndrome was biochemically confirmed. The ACTH level was in the normal range, which raised the suspicion of ACTH precursor-dependent disease. Elevated ACTH precursors were detected, supporting the diagnosis of ectopic ACTH syndrome. Functional imaging followed by tissue sampling revealed a pancreatic yolk sac tumor. The final diagnosis was Cushing’s syndrome due to a yolk sac tumor. The patient received a steroidogenesis inhibitor and subsequent bilateral adrenalectomy for control of hypercortisolism. Her yolk sac tumor was treated with chemotherapy and targeted therapy. Cushing’s syndrome secondary to a yolk sac tumor is extremely rare. This case illustrated the utility of ACTH precursor measurement in confirming an ACTH-related pathology and distinguishing an ectopic from a pituitary source for Cushing’s syndrome.

Introduction

Ectopic adrenocorticotrophic hormone (ACTH) syndrome, also termed paraneoplastic Cushing’s syndrome, can be caused by the secretion of ACTH and/or ACTH precursors from ectopic tumors. The tumors concerned secrete ACTH precursors, including unprocessed proopiomelanocortin (POMC) and POMC-derived peptides, owing to the altered post-translational processing of POMC (1). These tumors are associated with intense hypercortisolism and various complications, such as hypertension, hyperglycemia, osteoporosis, infection risks, and thrombotic tendencies (2). Distinguishing ectopic from pituitary-dependent Cushing’s syndrome is often challenging. The two conditions are classically distinguished by their variable responses to dynamic endocrine tests, including the high-dose dexamethasone suppression test, the corticotrophin-releasing-factor (CRF) test, and the desmopressin test (3). Pituitary imaging may sometimes provide a diagnosis if a pituitary macroadenoma is identified at this juncture. The gold standard for diagnosing pituitary Cushing’s is a positive inferior petrosal sinus sampling (IPSS) result. The measurement of ACTH precursors is reported to have diagnostic value in this scenario (4).

The most common source of ectopic ACTH is intrathoracic tumors, including bronchial carcinoid and small cell lung cancers. Other possible sources include gut neuroendocrine tumors and medullary thyroid cancer. Recognizing the potential causes of ectopic ACTH syndrome is essential as this provides guidance in locating the causative tumor and allows tumor-directed therapies. A yolk sac tumor as a cause of ectopic ACTH syndrome has only been reported in a 2-year-old child but not in adults (5). Here, we present a case of a 27-year-old Chinese woman who had Cushing’s syndrome due to ectopic ACTH precursor production from a pancreatic yolk sac tumor.

Case description

A 27-year-old Chinese woman, who had unremarkable past health and family history, presented with right upper quadrant abdominal pain and nausea in early 2020. Abdominal ultrasonography was unrevealing. A few months later, she developed Cushingoid features and oligomenorrhea. At presentation, her blood pressure was 160/95 mmHg, body weight was 65.6 kg, and body mass index was 23.2 kg/m2. She had a moon face, hirsutism, proximal myopathy, bruising, thinning of the skin, and acne. She also had hyperpigmentation on the nails and knuckles of both hands (Figure 1).

Figure 1
www.frontiersin.orgFigure 1. Cushingoid features at presentation include moon face, acne, thin skin, and easy bruising. Hyperpigmentation on the nails and knuckles was also noted.

Diagnostic assessments

Her 9 am and 9 pm cortisol were both >1,700 nmol/L. Her 24-h urine-free cortisol was beyond the upper measurable limit at >1,500 nmol/L. Her serum cortisol was 759 nmol/L after a 1 mg overnight-dexamethasone suppression test, confirming endogenous Cushing’s syndrome. The morning ACTH was 35 pg/mL (upper limit of normal is 46 pg/mL). After excluding a high dose-hook effect, her blood sample was concomitantly sent for ACTH measurement using two different platforms to eliminate possible interference, which might cause a falsely low ACTH reading. ACTH was 19 pg/mL (upper limit of normal is 46 pg/mL) using an IMMULITE 2000 XPI, Siemens Healthineers, Erlangen, Germany, and 17 pg/mL (reference range: 7–63 pg/mL) using a Cobas e-801, Roche Diagnostics, Indianapolis, IN, United States, therefore verifying the ACTH measurement.

In view of this being ACTH-dependent Cushing’s syndrome, a high-dose-dexamethasone suppression test (HDDST) was performed, and her cortisol was not suppressed at 890 nmol/L, with ACTH 42 pg/mL. The serum cortisol day profile showed a mean cortisol level of >1,700 nmol/L (i.e., higher than the upper measurable limit of the assay) and an ACTH of 17 pg/mL. A CRF test using 100 μg of corticorelin showed less than a 50% rise in ACTH and no rise in cortisol levels (Supplementary Table S1). She suffered from multiple complications of hypercortisolism, including thoracic vertebral collapse with back pain, diabetes mellitus (HbA1c 6.7% and fasting glucose 7.6 mmol/L), and hypokalemic hypertension, with a lowest potassium level of 2.3 mmol/L.

The rapid onset of intense hypercortisolism and refractory hypokalemia, as well as the responses in the HDDST and CRF tests raised the suspicion of ectopic ACTH syndrome. Tumor markers were measured. Alpha-fetoprotein (AFP) was markedly raised at 33,357 ng/mL (reference range: <9 ng/mL). Beta-human chorionic gonadotropin (beta-hCG) was not elevated. Carcinoembryonic antigen (CEA) was 4.0 ng/mL (reference range: <3 ng/mL) and CA 19–9 was 57 U/mL (reference range: <37 U/mL). The marked hyperpigmentation in the context of normal ACTH levels pointed to the presence of an underlying tumor producing circulating ACTH precursors. Hence, magnetic resonance imaging (MRI) of the pituitary gland was not performed at this juncture. ACTH precursors were measured using a specialized immunoenzymatic assay (IEMA) employing in-house monoclonal antibodies against the ACTH region and the gamma MSH region. Both monoclonal antibodies have to bind to these regions in POMC and pro-ACTH to create a signal. The patient had a level of 4,855 pmol/L (upper limit of normal is 40 pmol/L) (6). This supported Cushing’s syndrome from an ectopic source secondary to an excess in ACTH precursors.

Localization studies were arranged to identify the source of ectopic ACTH precursors. Computed tomography (CT) of the thorax did not show any significant intrathoracic lesion but incidentally revealed a pancreatic mass. Dedicated CT of the abdomen confirmed the presence of a 7.9 × 5.6 cm lobulated mass in the pancreatic body; the adrenal glands were unremarkable. 18-FDG and 68Ga-DOTATATE dual-tracer positron-emission tomography-computed tomography (PET-CT) showed that the pancreatic mass was moderately FDG-avid and non-avid for DOTATATE (Supplementary Figure S1). Multiple FDG-avid nodal metastases were also present, including left supraclavicular fossa lymph nodes.

Fine needle aspiration of the left supraclavicular fossa lymph node yielded tumor cells featuring occasional conspicuous nucleoli, granular coarse chromatin, irregular nuclei, and a high nuclear-to-cytoplasmic ratio. Mitotic figures were infrequent. On immunostaining, the tumor cells were positive for cytokeratin 7 and negative for cytokeratin 20. Focal expression of CDX-2, chromogranin, and synaptophysin was noted. They were negative for TTF-1, GCDPF, Gata 3, Pax-8, CD56, ACTH, inhibin, and S-100 protein. Further immunostaining was performed in view of highly elevated AFP. The tumor cells expressed AFP, Sall4, and MNF-116. They were negative for c-kit, calretinin, Melan A and SF-1. Placental ALP (PLAP) was weak and equivocal. The features were in keeping with a yolk sac tumor.

Therapeutic intervention and outcome

The patient had significant hypokalemic hypertension requiring losartan 100 mg daily, spironolactone 100 mg daily, and a potassium supplement of 129 mmol/day. Co-trimoxazole was given for prophylaxis against Pneumocystis jirovecii pneumonia. Metyrapone was started and up-titrated to 1 gram three times per day. However, in view of persistent hypercortisolism, with urinary free cortisol persistently above the upper measurable limit of the assay, bilateral adrenalectomy was performed. The tumor was mainly in the periadrenal soft tissue, with vascular invasion. The tumor formed cords, nests, and ill-defined lumen (Figure 2). The tumor cells were polygonal and contained pale to eosinophilic cytoplasm and pleomorphic nuclei, some with large nucleoli. Mitosis was present while tumor necrosis was not obvious. The stroma was composed of vascular fibrous tissue, with minimal inflammatory reaction. Immunohistochemical study showed that the tumor was positive for cytokeratin 7, MNF-116, AFP, and glypican-3, and also positive for Sall4 and HNF1β. The tumor cells were negative for cytokeratin 20, PLAP, CD30, negative for neuroendocrine markers including S100 protein, synaptophysin, chromogranin, and also negative for Melan-A, inhibin, and ACTH. Histochemical study for Periodic acid–Schiff–diastase (PAS/D) showed no cytoplasmic zymogen granules like those of acinar cell tumor. The features were compatible with yolk sac tumor. She was put on glucocorticoid and mineralocorticoid replacements post-operatively.

Figure 2
www.frontiersin.orgFigure 2. Histology and immunohistochemical staining pattern of tumor specimen. (A) HE stain x 40 showing tumor cells in the soft tissue and peritoneum. (B) HE × 400 showing that the tumor forms cords, nests, and ill-formed lumen in the vascular stroma. The tumor cells are polygonal with pale cytoplasm and pleomorphic nuclei. (C) PAS/D stain showing no cytoplasmic zymogen granules. (D) Tumor is diffusely positive for cytokeratin 7. (E) Tumor is positive for AFP. (F) Tumor is positive for glypican-3. (G) Tumor is diffusely positive for HNF1β. (H) Tumor is diffusely positive for SALL4.

Regarding her oncological management, she received multiple lines of chemotherapy, but the response was poor. Due to limited access to the ACTH precursor assay, serial measurement was unavailable. Treatment response was monitored by repeated imaging and monitoring of AFP. Figure 3 shows a timeline indicating the key events of the disease, showing the trends of the AFP and cortisol levels. Apart from (i) bleomycin, etoposide, and platinum, she was sequentially treated with (ii) etoposide, ifosfamide with cisplatin, and (iii) palliative gemcitabine with oxaliplatin. Next-generation sequencing showed a BRAF V600E mutation, for which (iv) dabrafenib and trametinib were given. Unfortunately, the disease progressed, and the patient succumbed approximately one year after the disease was diagnosed.

Figure 3
www.frontiersin.orgFigure 3. Timeline with serial cortisol and alpha-fetoprotein levels from diagnosis to patient death.

Discussion

This case demonstrates the diagnostic value of ACTH precursor measurement in the diagnosis of ectopic Cushing’s syndrome. ACTH precursors are raised in all ectopic tumors responsible for Cushing’s syndrome and could be useful in distinguishing ectopic from pituitary Cushing’s syndrome (4). Moreover, Cushing’s syndrome due to a yolk sac tumor has been reported only once in a pediatric case, and this is the first adult case reported in the literature (5).

POMC is sequentially cleaved in the anterior pituitary into pro-ACTH and then into ACTH, which is released into the circulation and binds to ACTH receptors in the adrenal cortex, leading to glucocorticoid synthesis (57). Due to incomplete processing, ACTH precursors are found in normal subjects at a concentration of 5–40 pmol/L (6). Pituitary tumors are traditionally well-differentiated and can also relatively efficiently process ACTH precursors. However, this processing is less efficient in ectopic tumors that cause Cushing’s syndrome (8). Some less differentiated pituitary macroadenomas can secrete ACTH precursors into the circulation; however, these tumors are diagnosed by imaging and so do not, in general, cause problems with differential diagnosis (9).

Measurement of ACTH precursors by immunoradiometric assay (IRMA) was first described by Crosby et al. (10). The assay utilized monoclonal antibodies specific for ACTH and the other binding gamma-MSH. The assay only detects peptides expressing both epitopes and therefore measures POMC and pro-ACTH. The assay does not cross-react with other POMC-derived peptides such as beta-lipotropin, ACTH, and N-POMC.

Oliver et al. demonstrated that, compared to the pituitary adenomas in Cushing’s disease, all ectopic tumors responsible for Cushing’s syndrome in their study produce excessive POMC and pro-ACTH (4). The excessive production of ACTH precursors may reflect neoplasm-induced modification and amplification of POMC production. It is suggested that POMC binds to and activates the ACTH receptor because it contains the ACTH amino-acid sequence, or it is cleaved to ACTH in the adrenal glands to cause hypercortisolism (5) (Figure 4). Moreover, cleavage of POMC may produce peptides that exert mitogenic actions on adrenal cells and lead to adrenocortical growth. Outside the adrenal tissue, excessive ACTH precursors in Cushing’s syndrome caused by ectopic tumors can lead to marked hyperpigmentation. Both hypercortisolism and hyperpigmentation were observed in the reported case.

Figure 4
www.frontiersin.orgFigure 4. Postulated pathological mechanism of ectopic ACTH precursors.

In patients with ACTH-dependent Cushing’s syndrome, ectopic tumors should be distinguished from pituitary tumors. The HDDST, at a cut-off of 50% cortisol suppression, gives a sensitivity of 81% and a specificity of 67% for pituitary dependent Cushing’s syndrome (11). The CRF test provides 82% sensitivity and 75% specificity for pituitary disease (8). IPSS is the gold standard in distinguishing pituitary from ectopic tumors in Cushing’s syndrome. Utilization of CRF-stimulated IPSS provides 93% sensitivity and 100% specificity for pituitary disease. It also allows correct lateralization in 78% of patients with pituitary tumors. However, it is only available in specialized centers.

In a retrospective cohort, the ACTH precursor level distinguished well between Cushing’s disease and ectopic ACTH syndrome (4). With a cut-off of 100 pmol/L, the test achieved 100% sensitivity and specificity for ectopic ACTH syndrome. More recently, this assay has been used to diagnose patients with occult ectopic ACTH syndrome, with ACTH precursors above 36 pmol/L (8). Unfortunately, the immunoassay for ACTH precursor measurement utilizes in-house monoclonal antibodies, which are not widely available.

Cross-reactivity of POMC in commercially available ACTH assays ranges from 1.6% to 4.7% (12). In cases of ectopic tumors causing Cushing’s syndrome with markedly raised ACTH-precursors and intense hypercortisolism, the cross-reactivity would give significantly high ‘ACTH’ measurements to suggest an ACTH-related pathology. The degree of cross-reactivity, which is variable, should ideally be provided by the assay manufacturer as it affects result interpretation. Lower levels of ACTH precursor production might not be detected, especially by assays with low precursor cross-reactivity. Clinical vigilance is crucial in reaching the correct diagnosis. In patients with marked hypercortisolism and a normal ACTH concentration, like in this case, the measurement of ACTH precursors would allow the accurate diagnosis of Cushing’s syndrome caused by ACTH precursors.

Ectopic tumors causing Cushing’s syndrome are associated with more intense hypercortisolism than Cushing’s disease (11). However, due to variable cross-reactivity, commercial ACTH assays might not accurately detect the excessive ACTH precursors responsible for the clinical syndrome. For this reason, ACTH measurements in these two conditions can significantly overlap and may not differentiate between ectopic and pituitary diseases (4). On the other hand, the more specific POMC assay described in 1996, which does not cross-react with pro-ACTH, has a low sensitivity of 80% for ectopic Cushing’s syndrome and is not now available (13). Hence, the ACTH precursor assay used in this reported case, which detects POMC and pro-ACTH, appears to provide the best diagnostic accuracy from the available literature.

Serial measurement of ACTH precursors may play a role in monitoring the treatment response in an ACTH precursor secreting tumor. In the case of ectopic ACTH secretion, the corticotropic axis is slowed down and ACTH is almost exclusively of paraneoplastic origin. Immunotherapy is known to alter the functioning of the hypothalamic–pituitary corticotropic axis; however, its effect on ectopic secretions is not known. More data is required before the role of ACTH precursor measurement for disease monitoring in these scenarios can be ascertained.

The incidence of endogenous Cushing’s syndrome is reported to be 2 to 4 per million people per year (14). Ectopic sources of Cushing’s syndrome are responsible for 9 to 18% of these cases. Typical sources of these ectopic tumors include bronchial carcinoid tumors, small-cell lung cancer, and gut neuroendocrine tumors. Notably, germ cell tumors, including teratomas, ovarian epithelial tumors, and ovarian endometrial tumors, are also possible ectopic sources of Cushing’s syndrome.

The histological diagnosis of germ cell tumor in a non-genital site is challenging, especially for the poorly differentiated, or with somatic differentiation. Immunostaining, chromosomal, or genetic study are very important in confirming the diagnosis. AFP elevation in our case limited the differential diagnoses to germ cell tumors/yolk sac tumors, hepatocellular carcinoma, and rare pancreatic tumors. The specimen was biopsied from the retroperitoneum, and the morphology was a dominant trabecular pattern or a hepatoid pattern. It showed diffuse positive immunostaining for cytokeratin, AFP, and glypican-3. It was also diffusely and strongly positive for HNF1β and SALL4, supporting the diagnosis of yolk sac tumor. Both HNF1β and SALL4, being related with the expression of genes associated with stem cells or progenitor cells, are used as sensitive and specific markers for germ cell tumors/yolk sac tumors (1516).

Staining related to pancreatic acinar cell carcinoma and neuroendocrine tumor were performed. PAS/D staining showed a lack of zymogen granules. A lack of nuclear β-catenin positivity was shown. Staining for neuroendocrine markers, including chromogranin and synaptophysin, was negative. Bcl-10 and trypsin were not available in the local setting.

Cushing’s syndrome due to a yolk sac tumor was reported only once, in a 2-year-old child (5). The abdominal yolk sac tumor was resistant to cisplatin, with rapid disease progression, and the patient succumbed 1.5 years after initial presentation. Yolk sac tumor in the pancreas is also rare, with only 4 cases reported so far. The first case was reported in a 57-year-old woman with an incidentally detected abdominal mass (17). The tumor stained positive for AFP, PLAP, and CEA. The second case was a 70-year-old asymptomatic woman with histology showing a group of tumor cells with features of a yolk sac tumor, and another group showing features of pancreatic ductal adenocarcinoma with mucin production, suggesting a yolk sac tumor derived from pancreatic ductal adenocarcinoma (18). The tumor showed partial positivity for AFP, Sall4, glypican-3, and cytokeratin 7, as found in our case, while MNF-116 and PLAP staining results were not described. The third was in a 33-year-old man with a solitary pancreatic head mass with obstructive jaundice (19). The patient had undergone Whipple’s procedure followed by cisplatin-based chemotherapy, resulting in at least 5 years of disease remission. The latest reported case was in a 32-year-old man presenting with abdominal pain (20). Notably, initial imaging showed diffuse enlargement of the pancreas and increased FDG uptake without a distinct mass. Reassessment imaging 11 months later showed a 13 cm pancreatic mass. The initial imaging findings suggested initial intraductal growth of the tumor, as reported in some subtypes of pancreatic carcinoma. None of the reported cases of adult pancreatic yolk sac tumors were associated with abnormal hormone secretion. We reported the first adult case of pancreatic yolk sac tumor with ectopic ACTH syndrome. The case represents an overlap of two rarities. It demonstrates that pancreatic yolk sac tumor is a possible cause of ectopic ACTH syndrome.

Conclusion

ACTH precursor measurement helps to distinguish ectopic ACTH syndrome from Cushing’s disease. The test has superior diagnostic performance and is less invasive than IPSS. Nonetheless, the limited availability of the assay may restrict its broader use in patient management. We describe the first adult case of pancreatic yolk sac tumor with ACTH precursor secretion resulting in Cushing’s syndrome. This adds to the list of origins of ectopic ACTH syndrome in adults.

Data availability statement

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding author.

Ethics statement

Written informed consent was obtained from the individual to publish any potentially identifiable images or data in this article.

Author contributions

JC wrote the manuscript. JC, CW, WC, AW, KW, and PT researched the data. WC, AL, EL, YW, KT, KL, and CL critically reviewed and edited the manuscript. DL initiated and conceptualized this case report and is the guarantor of this work. All authors contributed to the article and approved the submitted version.

Funding

The author(s) declare that no financial support was received for the research, authorship, and/or publication of this article.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Supplementary material

The Supplementary material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmed.2023.1246796/full#supplementary-material

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Keywords: Cushing’s syndrome, ectopic ACTH syndrome, yolk sac tumor, pancreatic tumor, ACTH precursor

Citation: Chang JYC, Woo CSL, Chow WS, White A, Wong KC, Tsui P, Lee ACH, Leung EKH, Woo YC, Tan KCB, Lam KSL, Lee CH and Lui DTW (2023) Cushing’s syndrome caused by ACTH precursors secreted from a pancreatic yolk sac tumor in an adult—a case report and literature review. Front. Med. 10:1246796. doi: 10.3389/fmed.2023.1246796

Received: 18 July 2023; Accepted: 20 November 2023;
Published: 05 December 2023.

Edited by:

Alessandro Vanoli, University of Pavia, Italy

Reviewed by:

Petar Brlek, St. Catherine Specialty Hospital, Croatia
Wafa Alaya, Hospital University Tahar Sfar, Tunisia

Copyright © 2023 Chang, Woo, Chow, White, Wong, Tsui, Lee, Leung, Woo, Tan, Lam, Lee and Lui. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: David Tak Wai Lui, dtwlui@hku.hk

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

From https://www.frontiersin.org/articles/10.3389/fmed.2023.1246796/full

Ectopic Adrenocorticotropic Hormone-Secreting Pituitary Adenoma in the Clivus Region: A Case Report

Yan Zhang, Danrong Wu, Ruoqiu Wang, Min Luo, Dong Wang, Kaiyue Wang, Yi Ai, Li Zheng, Qiao Zhang, Lixin Shi

Department of Endocrinology and Metabolism, Guiqian International General Hospital, Guiyang, People’s Republic of China

Correspondence: Qiao Zhang; Lixin Shi, Department of Endocrinology and Metabolism, Guiqian International General Hospital, Guiyang, People’s Republic of China, Tel/Fax +86 851-86277666, Email endocrine_zq@126.com; slx1962@medmail.com.cn

Abstract: Ectopic pituitary adenoma (EPA) is a pituitary adenoma unrelated to the intrasellar component and is an extremely rare disease. EPA resembles typical pituitary adenomas in morphology, immunohistochemistry, and hormonal activity, and it may present with specific or non-specific endocrine manifestations. Here, we report a rare case of ectopic adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma in the clival region. Only three patients with ACTH-secreting pituitary adenomas occurring in the clivus have been previously reported, and the present case was diagnosed as a clivus-ectopic ACTH-secreting pituitary macroadenoma. Thus, in addition to the more common organs, such as the lung, thymus, and pancreas, in the diagnosis of ectopic ACTH syndrome, special attention should be paid to the extremely rare ectopic ACTH-secreting pituitary adenoma of the clivus region.

Keywords: ectopic pituitary adenoma, Cushing’s syndrome, clivus, adrenocorticotropic hormone, endocrine

Introduction

The diagnosis of Cushing’s syndrome (CS), particularly its localization diagnosis, has always been a challenge in clinical practice.1,2 Endogenous CS can be divided into adrenocorticotropic hormone (ACTH)-dependent and non-ACTH dependent with the former accounting for 70% of CS cases. Ectopic ACTH syndrome accounts for 5–10% of CS cases, and its lesions are mainly located in the lungs, thymus, pancreas, and the thyroid gland.3 Finding such lesions in non-pituitary intracranial regions is extremely rare, and ectopic ACTH in the clivus region is even rarer. To date, less than 60 cases of ectopic ACTH-secreting pituitary adenomas have been reported,4 and determining their localization is a formidable challenge in CS diagnosis. It is difficult to make an accurate and prompt diagnosis of ectopic ACTH-secreting pituitary adenoma caused by hypercortisolism based on its clinical manifestation, routine laboratory tests, and radiologic examinations.1,4 Ectopic pituitary adenomas (EPAs) are mainly concentrated in the sphenoid sinus, suprasellar region, and cavernous sinus, and rare regions include the clivus, ethmoid sinus, and nasal cavity.5 A literature review showed that only three cases of primary EPA in the clivus region have been reported worldwide.6–8 Recently, we diagnosed a patient with ectopic ACTH-secreting pituitary macroadenoma in the clivus region that was confirmed by surgery and immunohistochemistry.

Case Presentation

A 53-year-old female patient sought medical attention at our hospital for hypertension, headache, and dizziness with a blood pressure as high as 180/100 mmHg. Her medical history showed that she had developed similar symptoms 2 years ago. At that time, she had hypertension (180/100 mmHg), headache, and dizziness, and she was treated with amlodipine (5 mg per day), benazepril hydrochloride (10 mg per day), and metoprolol tartrate (50 mg per day). The patient was not hospitalized for treatment and did not undergo systemic examination. Three months before admission, the patient had a thoracic vertebrae fracture caused by moving heavy objects. One month before admission, she had a bilateral rib fracture due to falling on flat ground. Her physical examination results were as follows: blood pressure, 160/85 mmHg; height, 147 cm; weight, 55.2 kg; and body mass index (BMI), 25.54 kg/m2. In the physical examination, moon facies, buffalo hump, concentric obesity, facial plethora, and large patches of ecchymosis at the blood sampling site were observed. Purple striae were absent below the axilla, abdomen, and limbs. Her hematological examination results were as follows: cortisol (COR) rhythm with 33.52 µg/dL (reference range: 4.26–24.85) at 8:00 AM, 34.3 µg/dL at 4:00 PM, and 33.14 µg/dL at 12:00 AM; 1 mg dexamethasone overnight suppression test indicated 22.21 µg/dL COR at 8:00 AM; 24 h urine COR was 962.16 µg/24 h (reference range: 50–437 µg/24 h); 8:00 AM ACTH at two different times was 74 pg/mL and 90.8 pg/mL (reference range: <46); high-dose dexamethasone suppression test (HDDST) was 21.44 µg/dL COR (serum COR level was not suppressed by more than 50%); serum potassium was 3.38 mmol/L (reference range: 3.5–5.5); insulin-like growth factor-1 (IGF-1) was 106.6 ng/mL (reference range: 84–236); serum luteinizing hormone (LH) was <0.07 IU/L (reference range: 1.9–12.5); serum follicle stimulating hormone (FSH) was 0.37 IU/L (reference range: 2.5–10.2); prolactin (PRL), testosterone, progesterone, and estradiol test results were normal; FT4 was 8.25 pmol/L (reference range: 10.44–24.38); TSH was 1.116 mIU/L (reference range: 0.55–4.78); oral glucose tolerance test (OGTT) indicated that fasting blood glucose was 6.3 mmol/L and 2-h blood glucose was 18.72 mmol/L; and glycated hemoglobin (HbA1c) was 7.1%. A bone mineral density test suggested osteoporosis (dual energy X-rays: L1-L4 T values were −3.4).

Magnetic resonance (MR) scans were performed using a SIGNA Pioneer 3.0T (GE Healthcare, Waukesha, WI, USA), and computed tomography (CT) scans were performed using a 256 slice CT scanner (Revolution CT; GE Healthcare, Waukesha, WI, USA). The enhanced MR scan of the sellar lesion showed a soft tissue mass with abnormal signals in the occipital bone clivus. T1WI showed an isointense signal, and T2WI showed an isointense/slightly hyperintense signal in a large area of approximately 30 mm × 46 mm. The lesion extended anteriorly to completely fill the entire sphenoidal sinus, and it was in a close proximity to the right internal carotid arteries. Significant invasion, liquefaction, and necrosis were not observed in the bilateral cavernous sinuses. Pituitary gland morphology was normal with a superoinferior diameter of 3.14 mm, and the pituitary gland was located in the center. An occipital bone clival space-occupying lesion was considered with a tendency of low malignancy and a possibility of chordoma (Figure 1A–C). Non-enhanced high-resolution CT scans of the nasal sinuses showed osteolytic destruction, and a soft tissue mass was observed in the occipital bone clivus. The mass had a large area of 20 mm × 30 mm × 46 mm (Figure 1D). Enhanced CT of the adrenals showed bilateral adrenal gland hyperplasia.

Figure 1 (A) MR T1+T2 scan (transverse view). MR T1 scan (left) shows the soft tissue mass of the occipital clivus (white arrow), and MR T2 scan (right) shows that the right internal carotid artery, cavernous sinus, and tumor are within close proximity to each other (white arrow). (B) MR T1 enhanced scan (sagittal view) shows clear demarcation between normal pituitary gland and mass (white arrow). (C) MR T2 scan (sagittal view) shows that the pituitary fossa is normally present (white arrow). (D) CT (sagittal view) shows bony destruction of dorsum sellae, clivus, and sphenoid sinus by mass (white arrow).

Bilateral inferior petrosal sinus sampling (IPSS) combined with a desmopressin stimulation test had the following results: baseline ACTH at left inferior petrosal sinus/periphery (IPS/P), 5.4; post-stimulation IPS/P, 3.42; stimulation corrected (ACTHPRL) IPS/P, 2.8; right baseline IPS/P, 1.64; post-stimulation IPS/P, 9.34; and stimulation corrected IPS/P, 6.92. The left inferior petrosal sinus was the dominant side (Table 1).

Table 1 Bilateral Inferior Petrosal Sinus Sampling Combined with Desmopressin Stimulation Test

The patient underwent endoscopic transsphenoidal clival lesion resection surgery, and the postoperative pathology test results showed EPA (Figure 2). The immunohistochemistry staining results were as follows: CK (+), SYN (+), CgA (+), ACTH (+), growth hormone (GH) (−), LH (−), TSH (−), PRL (−), FSH (−), and Ki-67 (<1% +). The COR level at 10 days after surgery was 15.87 µg/dL, and the ACTH level was 31.37 pg/mL (Table 2).

Table 2 Changes in COR and ACTH Levels During Course of Treatment
Figure 2 Pathological diagnosis of (clivus) ectopic pituitary adenoma. (A) Pituitary adenoma revealing a trabecular and nested structure revealing vascular invasion (hematoxylin and eosin (HE) stain, 200x) composed of two distinct types of cells. (B) ACTH expression in the EPA (200x, ACTH-antibody, Dako).

After admission, her blood and urine COR levels were significantly elevated, and a qualitative diagnosis of CS was obtained. Etiological examination found that ACTH was also significantly elevated, suggesting that the CS was ACTH dependent. The HDDST results showed that the serum COR level was not suppressed by more than 50% and was accompanied by hypokalemia, suggesting that the ACTH-dependent CS may be ectopic ACTH syndrome. Ectopic ACTH syndrome is relatively rare, and the lesions are caused by non-pituitary tumors. No lesions were identified in the lung, thymus, pancreas, and thyroid of our patient. Regarding the IPSS examination, the IPS/P ratio was greater than 2, which suggested that the ectopic ACTH was located intracranially and not at the periphery. Radiologic testing suggested that the pituitary structure was normal and that a space-occupying lesion in the clivus region was present. Therefore, ectopic ACTH-secreting adenoma in the clivus region was considered, and postoperative pathological biopsy was used to confirm the diagnosis.

Discussion

EPA is an extremely rare disease that occurs outside of the sella turcica, and it is not linked to the intrasellar pituitary. The morphology, immunohistochemistry, and hormone activity of EPAs are similar to typical pituitary adenomas. EPAs can manifest as specific or non-specific endocrine disorders, and they account for 0.48% of all pituitary adenomas.9 The pathogenesis of EPA is still currently unknown. It is generally considered that during the development of the anterior pituitary lobe, the incompletely degraded Rathke cleft cyst remnants of the Rathke pouch lead to the formation of EPAs in the nasopharynx, sphenoid, and clivus.10,11 EPA is rare in China. Zhu et al5 recorded 14,357 pituitary gland patients in the last 20 years; of these patients, only 14 were diagnosed with EPA (0.098% of all cases), but none of the lesions originated from the clivus region. Previous literature reviews4,5 revealed that non-functioning EPAs in the clivus region are the most common (50%); the most common hormone-secreting functional adenomas are PRL adenomas and GH adenomas, which account for 25.0% and 21.4% of EPAs, respectively, whereas ACTH-secreting EPAs are extremely rare and only account for 3.6% of cases.

The postoperative pathological and immunohistochemical results of the tumor tissue in the patient demonstrated that it was an ectopic ACTH-secreting pituitary macroadenoma in the clivus region. Most EPAs are microadenomas (diameter <1 cm), except those in the clivus region, which are macroadenomas.5 Adenoma size generally does not affect the patient’s clinical and biochemical characteristics, and it may be related to tumor location or extension.12 Encasement of the internal carotid artery is a characteristic feature of EPA invasion into surrounding tissues.5 Encasement of the right internal carotid artery by the tumor was also observed in our patient. Therefore, surgery cannot completely remove the tumor and may ultimately affect surgical outcomes, and radiotherapy may even be required in the future. The serum COR and ACTH levels of our patient were evaluated 10 days after surgery. Although the levels were significantly lower than those before the surgery, the COR level was still significantly higher than the cutoff value of 1 µg/dL,13,14 suggesting that the patient may not have complete remission due to the incomplete tumor resection in the area adjacent to the carotid artery during surgery. Another feature that was observed in our patient was bone invasion. Because the clivus is composed of abundant cancellous bone that is connected to surrounding bone structures, EPAs or other tumors may cause bone destruction and affect the sphenoidal sinus and cavernous sinus, which is also consistent with literature reports.15,16

Due to the low incidence of EPAs, most EPA cases are reported as case reports in the literature. We performed an English literature search using the PubMed and Web of Science Core Collection databases with the following predetermined terms: “Cushing’s syndrome”, “pituitary adenomas”, “clivus”, “ectopic pituitary adenoma”, and “adrenocorticotropic”. The literature was included if it met the following criteria: (i) the confirmed diagnosis of CS or ectopic ACTH syndrome was described in the literature; (ii) the diagnosis of EPA was confirmed by postoperative inspection; and (iii) EPA occurred in the clivus. After excluding cases of clival invasion from other sites, we found only three reports of ectopic ACTH-secreting adenoma in the clivus region,6–8 and they were all female patients. Ortiz-Suarez and Erickson6 employed transfrontal craniotomy to demonstrate that the ectopic ACTH-secreting adenoma was an extension of extrasellar lesion to the clivus. In a case report by Pluta et al,7 the patient was found to have cavernous sinus and clival ACTH-positive tumors through transphenoidal surgery. In a case report by Aftab et al,8 the patient only presented a space-occupying lesion with unilateral vision loss; the patient was initially diagnosed with clival chordoma, but the postoperative results supported the diagnosis of EPA. Based on preoperative imaging, the possibility of chordoma was also considered to be high in our patient. We combined the clinical manifestation and laboratory test results of the patient and considered the etiology of CS to conclude that the patient had clival ectopic ACTH-secreting adenoma instead of chordoma.

Hormone tests in our patient suggested secondary pituitary-gonadal axis and decreased pituitary-thyroid axis function. These changes in endocrine function may be due to pituitary suppression by hypercortisolism. After surgery, the corresponding markers recovered, indicating that the suppression was transient. The patient has a history of fracture and a bone mineral density suggestive of osteoporosis, which may also be associated with CS hypercortisolemia.

Treatment modalities for EPA include adenoma resection surgery, radiotherapy, and drugs. The first-line recommended treatment is surgical resection. Craniotomy is considered the surgical procedure of choice for EPA, and endoscopic transsphenoidal surgery (TSS) is considered a feasible method for preserving pituitary function while simultaneously treating EPA. However, due to limitations with the surgical operation space, there are still concerns whether sufficient exploration and effective tumor resection can be achieved.17 Because there are few case reports of such patients, the long-term outcomes of these two surgical procedures require further validation. Due to differences in EPA sites and functions, the efficacy of surgery also differs. Zhu et al5 reported that compared to the radical resection rate of sphenoidal sinus and cavernous sinus EPA (72.3% and 73.3%, respectively), the radical resection rate of clival EPA is only 45.0%, and this difference is statistically significant.

The three clival EPA patients described in the three relevant publications6–8 all showed significant improvements in postoperative signs, symptoms, and hormone levels after complete surgical removal of the lesions or combined with radiation therapy. In our patient, however, radical resection of the tumor could not be achieved due to the close proximity of the tumor mass to the right internal carotid artery, and surgery could not be used to achieve complete remission, which is similar to the case reported by Zhu et al.5 For such patients, radiotherapy can be considered as a second-line treatment for EPA. To control hormone levels, drugs and bilateral adrenalectomy are also treatment options.5,18,19

Conclusion

EPA is a rare disease, and clival EPA is even rarer. From the entire diagnosis and treatment course, this unique and rare EPA case was preliminarily diagnosed through a comprehensive hormone panel and IPSS, and it was confirmed by pathology and immunohistochemistry after surgery. In the diagnosis of ectopic ACTH syndrome, attention should also be paid to extremely rare pituitary ectopic sites, such as the sphenoid sinuses, parasellar region, and the clivus, in addition to common sites, such as the lungs, thymus, pancreas, and thyroid.

Data Sharing Statement

The raw data supporting the conclusions of this article will be made available by the authors without undue reservation.

Informed Consent Statement

Prior written permission was obtained from the patient for treatment as well as for the preparation of this manuscript and for publication. Our institution approved the publication of the case details.

Acknowledgments

We would like to thank the patient and her family.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Funding

There is no funding to report.

Disclosure

The authors report no conflicts of interest in this work.

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Thyroid cancer: Cushing syndrome is a lesser-known warning sign – what is it?

Thyroid cancer survival rates are 84 percent for 10 years or more if diagnosed early. Early diagnosis is crucial therefore and spotting the unusual signs could be a matter of life and death. A sign your thyroid cancer has advanced includes Cushing syndrome.

What is it?

What is Cushing syndrome?

 

Cushing syndrome occurs when your body is exposed to high levels of the hormone cortisol for a long time, said the Mayo Clinic.

The health site continued: “Cushing syndrome, sometimes called hypercortisolism, may be caused by the use of oral corticosteroid medication.

“The condition can also occur when your body makes too much cortisol on its own.

“Too much cortisol can produce some of the hallmark signs of Cushing syndrome — a fatty hump between your shoulders, a rounded face, and pink or purple stretch marks on your skin.”

In a study published in the US National Library of Medicine National Institutes of Health, thyroid carcinoma and Cushing’s syndrome was further investigated.

The study noted: “Two cases of thyroid carcinoma and Cushing’s syndrome are reported.

“Both of our own cases were medullary carcinomas of the thyroid, and on reviewing the histology of five of the other cases all proved to be medullary carcinoma with identifiable amyloid in the stroma.

“A consideration of the temporal relationships of the development of the carcinoma and of Cushing’s syndrome suggested that in the two cases with papillary carcinoma these conditions could have been unrelated, but that in eight of the nine cases with medullary carcinoma there was evidence that thyroid carcinoma was present at the time of diagnosis of Cushing’s syndrome.

“Medullary carcinoma of the thyroid is also probably related to this group of tumours. It is suggested that the great majority of the tumours associated with Cushing’s syndrome are derived from cells of foregut origin which are endocrine in nature.”

In rare cases, adrenal tumours can cause Cushing syndrome a condition arising when a tumour secretes hormones the thyroid wouldn’t normally create.

Cushing syndrome associated with medullary thyroid cancer is uncommon.

The syndrome is more commonly caused by the pituitary gland overproducing adrenocorticotropic hormone (ACTH), or by taking oral corticosteroid medication.

See a GP if you have symptoms of thyroid cancer, warns the NHS.

The national health body added: “The symptoms may be caused by less serious conditions, such as an enlarged thyroid, so it’s important to get them checked.

“A GP will examine your neck and can organise a blood test to check how well your thyroid is working.

“If they think you could have cancer or they’re not sure what’s causing your symptoms, you’ll be referred to a hospital specialist for more tests.”

 

Adapted from https://www.express.co.uk/life-style/health/1351753/thyroid-cancer-signs-symptoms-cushing-syndrome

BIPSS Diagnostic Method May Cause False Positive in Some Cases of Cyclic Cushing’s Syndrome

A diagnostic technique called bilateral inferior petrosal sinus sampling (BIPSS), which measures the levels of the adrenocorticotropic hormone (ACTH) produced by the pituitary gland, should only be used to diagnose cyclic Cushing’s syndrome patients during periods of cortisol excess, a case report shows.

When it is used during a spontaneous remission period of cycling Cushing’s syndrome, this kind of sampling can lead to false results, the researchers found.

The study, “A pitfall of bilateral inferior petrosal sinus sampling in cyclic Cushing’s syndrome,” was published in BMC Endocrine Disorders.

Cushing’s syndrome is caused by abnormally high levels of the hormone cortisol. This is most often the result of a tumor on the pituitary gland that produces too much ACTH, which tells the adrenal glands to increase cortisol secretion.

However, the disease may also occur due to adrenal tumors or tumors elsewhere in the body that also produce excess ACTH — referred to as ectopic Cushing’s syndrome.

Because treatment strategies differ, doctors need to determine the root cause of the condition before deciding which treatment to choose.

BIPSS can be useful in this regard. It is considered a gold standard diagnostic tool to determine whether ACTH is being produced and released by the pituitary gland or by an ectopic tumor.

However, in people with cycling Cushing’s syndrome, this technique might not be foolproof.

Researchers reported the case of a 43-year-old woman who had rapidly cycling Cushing’s syndrome, meaning she had periods of excess cortisol with Cushing’s syndrome symptoms — low potassium, high blood pressure, and weight gain — followed by normal cortisol levels where symptoms resolved spontaneously.

In general, the length of each period can vary anywhere from a few hours to several months; in the case of this woman, they alternated relatively rapidly — over the course of weeks.

After conducting a series of blood tests and physical exams, researchers suspected of Cushing’s syndrome caused by an ACTH-producing tumor.

The patient eventually was diagnosed with ectopic Cushing’s disease, but a BIPSS sampling performed during a spontaneous remission period led to an initial false diagnosis of pituitary Cushing’s. As a result, the woman underwent an unnecessary exploratory pituitary surgery that revealed no tumor on the pituitary.

Additional imaging studies then identified a few metastatic lesions, some of which were removed surgically, as the likely source of ACTH. However, the primary tumor still hasn’t been definitively identified. At the time of publication, the patient was still being treated for Cushing’s-related symptoms and receiving chemotherapy.

There is still a question of why the initial BIPSS result was a false positive. The researchers think that the likely explanation is that BIPSS was performed during an “off phase,” when cortisol levels were comparatively low. In fact, a later BIPSS performed during a period of high cortisol levels showed no evidence of ACTH excess in the pituitary.

This case “demonstrates the importance of performing diagnostic tests only during the phases of active cortisol secretion, as soon as first symptoms appear,” the researchers concluded.

From https://cushingsdiseasenews.com/2020/01/02/cushings-syndrome-case-study-shows-drawback-in-bipss-method/

MEKT1 Could Be a Potential New Therapy for Treating Cushing’s Disease

MEKT1, a type of therapy called a PPAR-γ agonist, acts to reduce levels of the adrenocorticotropic hormone and could be a potential new therapy for Cushing’s disease, according to researchers.

Their study, “Inhibitory Effects of a Novel PPAR-γ Agonist MEKT1 on Pomc Expression/ACTH Secretion in AtT20 Cells,” was published in the journal PPAR Research.

Cushing’s disease is caused by a tumor in the pituitary gland — generally a type of tumor called an adenoma that produces high levels of adrenocorticotropic hormone (ACTH).

ACTH causes the adrenal glands to make too much cortisol, leading to the classic symptoms associated with Cushing’s disease.

PPAR-gamma (PPAR-γ) is a transcription factor protein (meaning it regulates the levels of certain genes by acting through other proteins), and is seen in high levels in the normal human pituitary and in ACTH-secreting pituitary adenomas.

The Pomc gene is a precursor molecule to ACTH. While it is known that PPAR-γ plays a role in regulating Pomc levels, its mechanism has not yet been clarified in pituitary cells.

PPAR-γ agonists — agents that activate PPAR-γ — include the medications rosiglitazone and pioglitazone, both of which are used to treat type 2 diabetes. Some studies have shown that rosiglitazone and pioglitazone have an effect on Pomc suppression, which would lead to lower levels of ACTH and help treat patients with Cushing’s disease.

However, the benefits of PPAR-γ agonists in the treatment of Cushing’s disease are still controversial.

Researchers examined the effects of a new PPAR-γ agonist, MEKT1, on Pomc levels and ACTH secretion using a mouse pituitary tumor-derived cell line called AtT20 cells. They also compared its effects with the well-established PPAR-γ agonists rosiglitazone and pioglitazone.

AtT20 cells were treated with either MEKT1, rosiglitazone, or pioglitazone at various concentrations ranging from 1 nM to 10 μM (micrometers) for 24 hours.

Results showed that 10 μM of MEKT1 significantly inhibited Pomc gene levels compared to rosiglitazone and pioglitazone. Additionally, ACTH secretion from AtT20 cells was also significantly inhibited by the agonist.

To see if it worked to decrease Pomc levels by acting specifically on PPAR-γ, researchers eliminated the PPAR-γ protein using a technique called siRNA knockdown. In this case, the effects of MEKT1 on Pomc levels were significantly halted.

It is known that other proteins, such as Nur77, Nurr1, and Tpit activate Pomc levels by binding to the promoter region of Pomc — the area of the gene responsible for activating gene levels.

To determine whether these proteins could be targeted by MEKT1, researchers also looked at levels of Nur77, Nurr1, and Tpit. The PPAR-γ agonist was found to significantly suppress the levels of the three genes that encode these proteins.

“Although clinical trials of MEKT1 are needed to determine its drug efficacy in the future, it can be speculated that MEKT1 is much more effective than the previously recognized PPAR-γ agonists rosiglitazone, and pioglitazone for the suppression of Pomc expression/ACTH secretion from our in vitro [laboratory] research,” they added.

Results from this study suggest MEKT1 could be a potential new therapy for the treatment of Cushing’s disease.

From https://cushingsdiseasenews.com/2018/06/12/mekt1-could-be-potential-therapy-treatment-cushings-disease/