ResearchPad - tumor-biology https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[SAT-141 Glycoprotein NMB (GPNMB) Is Pro-Tumorigenic in TSC2-Null Cancer Cells and Is a Potential Drug Target and Biomarker for Lymphangioleiomyomatosis (LAM)]]> https://www.researchpad.co/article/elastic_article_9551 Lymphangioleiomyomatosis (LAM) is an estrogen-sensitive lung disease found almost exclusively in women that is characterized by hyperproliferation of smooth muscle cells forming small tumors, or LAM lesions throughout the lungs of patients. Growth of these tumors leads to progressive loss of pulmonary function, and sometimes subsequent lung transplantation. LAM tumor cells contain mutations in either the TSC1 or TSC2 genes, leading to activation of the mTORC1 pathway. In fact, mTOR inhibitors such as sirolimus are commonly used to treat LAM; however, these drugs are not always effective and have significant side effects, suggesting the need for new therapeutic targets. Interestingly, another important feature of LAM cells is that they express melanocytic markers that are normally found in melanocytes or melanoma cells. From RNASeq analysis of a mouse model for LAM that we designed, we discovered significant upregulation of the melanocytic marker Glycoprotein Non-Metastatic Melanoma Protein B (GPNMB), a type I transmembrane protein. GPNMB was not only highly expressed in our mouse model (a uterine specific TSC2-null mouse), it was also expressed in TSC2-null cell lines, and human LAM patient lung samples. In our hands, knocking down GPNMB expression by siRNA directed against GPNMB mRNA decreased migration and proliferation in TSC2-null cells. Additionally, we found that GPNMB’s large ectodomain is shed by TSC2-null cells and can be detected in the blood of human patients with LAM. Finally, MMP 2 and 9 can be secreted as a result of ectodomain shedding and its interaction with integrins. Accordingly, we did indeed see a decrease in MMP 2/9 expression in TSC2-null cells with reduced GPNMB expression from treatment with siRNA directed against GPNMB mRNA. Overall, our results demonstrate the potential importance of GPNMB in LAM tumor progression, and suggest that GPNMB may be a possible LAM biomarker and target for its treatment.

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<![CDATA[SUN-903 Insulinoma - a Tricker Diagnosis When Some Pieces Are Missing]]> https://www.researchpad.co/article/elastic_article_8801 Insulinoma is a rare pancreatic neuroendocrine tumour that secretes insulin, causing hypoglycemia. Because of the nonspecific symptoms, the diagnosis could constitute a challenge. Early detection is important to prevent serious consequences.

A 31-year old woman was admitted for prolonged fasting test. She had no relevant past medical or surgical history till eight months before, when she had an episode of generalized tonic-clonic seizure with loss of consciousness. At this time, she was taken to emergency, with identification of a hypoglycaemia of 33 mg/dL. Unfortunately this was undervalued and she was discharged with an appointment on a neurologist. After evaluation, she did an EEG, which was normal, and blood tests that identified a fasting glycemia of 50 mg/dL. By recommendation of her general practitioner, she began to monitor her glycemia during the day, identifying multiple glycemia <50mg/dL – in fasting and post-prandial period. After the first generalized seizure, she had multiple seizures, always associated with hypoglycaemia. During the night she had to wake up every two hours to eat, in order to prevent hypoglycaemia. Moreover, in the last 6 months, she augmented 12 Kg. She also described two episodes of behavioural changes with confusion and speech alteration.

She wasn’t under any medication that could be associated with hypoglycemias. Previous records showed she had a fasting glycemia of 50 mg/dL two years ago. When she was admitted to our department, besides she had eat one hour before, she had glycemia <55 mg/dL. Blood tests showed glucose level=22 mg/dL, insulin=39 μU/mL (normal range 2.6-24.9 μU/mL), C-Pep=0.90 ng/mL (normal range 1.1-4-4 ng/mL). Plasma B-hydroxybutyrate was negative. After Glucagon EV, glucose level increase to 53 mg/dL (>25 mg/dL). We also evaluated cortisol and growth hormone that were normal. Abdominal computed tomography scan with contrast demonstrated a well-defined hypervascular lesion involving pancreas tail. Abdominal MRI was also performed showing a hypervascular lesion involving pancreas tail with 11x21mm. Laparoscopic surgery to enucleate the lesion was made. Pathological evaluation revealed a well-differentiated neuroendocrine tumour (positive staining for synaptophysin, cromogranin and insulin) measuring 0.3 cm. The diagnosis of pancreatic insulinoma was confirmed. After surgery, the glucose level increased to the normal range. The patient is currently in 6 months follow-up with a good evolution.

The diagnosis of insulinoma requires high suspicion. In this case, the patient didn’t have the typical insidious neurogenic symptoms. There is a need to value neuroglycopenic symptoms associated with hypoglycemia, otherwise serious consequences can occur.

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<![CDATA[SAT-147 Endogenous Expression of TCF21 by CRISPR/dCas9 System Results in Different Biological Responses in Adrenocortical Carcinoma and Hepatocarcinoma]]> https://www.researchpad.co/article/elastic_article_8780 Transcription factor 21 (TCF21/POD-1/Epicardin) inhibits the expression of SF-1 (NR5A1) by binding to the promoter E-box site in adrenocortical carcinoma (ACC). In contrast, TCF21 promotes increased expression of LRH-1 in hepatocarcinoma cell line, HepG2 cells, by binding to the Small Heterodimer Partner (SHP/NR0B2) promoter region, an LRH-1 negative regulator. Epigenetic alteration induced TCF21 loss of function and has been associated with increased of cellular migration and invasion. In ACC, TCF21 promoter is hypermethylated and less expressed. Our aim was to evaluate the effect of TCF21 by expressing or silencing TCF21 in adrenocortical pediatric adenoma, ACA-T7 cells, in ACC cell lines SW-13 and H295R cell line, and in HepG2 cell line. Were used CRISPR/dCas9/TCF21 and pCMVMycPOD1 or siRNATCF21 to express and silence TCF21, respectively. Increased expression of TCF21 in H295RpCMVMycPOD1 and SW-13CRISPR/dCas9/TCF21 cells resulted in significantly decreased cell migration and invasion (53.2±36.1%/70.8±26.5% and 82.6±4.2%/100%, respectively). In ACA-T7/siRNATCF21 cells, the inhibition of TCF21 resulted in significant increase migration and invasion capacity (45.0±12.7%/33.1±17.4%) compared with ACA-T7 cells. Higher TCF21 expression in HepG2CRISPR/dCas9/TCF21 increased invasion [147.08±16.54% (p<0.0001)]. Analysis of metalloproteinase genes expression showed that TCF21 significantly (p<0.01) increased MMP8 expression in SW-13CRISPR/dCas9/TCF21 and H295R/pCMVMycPod-1 whereas decreased MMP9 and MMP2 (p< 0.0001). The opposite effect was observed in ACA-T7/siRNATCF21. Moreover, in HepG2CRISPR/dCas9/TCF21 cells was observed an increase of MMP2 and MMP9 expression (p<0.001). These results suggest that TCF21 regulate epithelial mesenchymal transition and vice versa (EMT/MET) in tumors depending on cellular context. Supported by Fapesp and Capes.

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<![CDATA[MON-917 Carney Complex Due to a Contiguous Gene Deletion Syndrome (17q24.2-17q24.3)]]> https://www.researchpad.co/article/elastic_article_8777 Background

While genomic rearrangements of chromosome 17 are not uncommon, deletions of chromosome band 17q24.2-q24.3 are rare, and associated features include cardiac abnormalities, characteristic facial appearance, short stature, obesity, syndactyly, intellectual disability, seizures, delayed dentition, and features of Carney Complex. It has been suggested that the involvement of KCNJ2, PRKCA, CACNG gene cluster (CACNG1, CACNG4, CACNG5), and PRKAR1A genes contribute to this phenotype. A case of a child with a 3.7 Mb deletion at chromosome band 17q24.2-q24.3, as well as a 2.1 Mb gain at chromosome 17q22, is described.

Clinical Case

A now 6 year old female was born at 34 weeks gestational age with prenatal course complicated by oligohydramnios and intrauterine growth restriction. Birth weight was at the 9th percentile, and birth length was at the 92nd percentile. She was noted to have a patent ductus arteriosus (PDA), poor suck and swallow, and dysmorphic features. Chromosome microarray revealed a 3.7 Mb deletion at Chromosome 17q24.2-q24.3, involving KCNJ2, PRKCA, CACNG gene cluster (CACNG1, CACNG4, CACNG5), and PRKAR1A, as well as a 2.1 Mb gain at Chromosome 17q22, involving C17orf112 and KIP2B.

At 6 years old, she continues to be small for weight (-4.5 SDs), BMI (-4.22 SDs), and height (-2.5 SDs), though with appropriate pre-pubertal linear growth velocity. She is minimally verbal and continues to receive physical, occupational and speech therapies. Examination showed dysmorphic facial features, including triangular face with pointed chin, prominent forehead with low-set ears, retro-micrognathia, almond-shaped eyes with up-slanting palpebral fissures, bulbous nose, thin lips, and irregularly-shaped teeth. She had bilateral 5th digit clinodactyly, tapering of the distal aspects of bilateral first digits of the hands, and syndactyly of bilateral 2nd/3rd digits of the feet. She had scant freckling over the nasal bridge and cheeks, as well as freckles of the left arm, left groin, and back. She had no clinical stigmata of hypercortisolism. Echocardiogram continues to show a PDA with no cardiac myxomas. Thyroid ultrasound was normal. However, she does have mild hypercalcemia, most recently 2.61 mmol/L (2.15-2.55), and mildly elevated alkaline phosphatase of 341 U/L (96-297).

Conclusion

This case highlights a child with many of the previously reported findings associated with 17q24.2-q24.3 deletions. However, she also was noted to have a 2.1 Mb gain at chromosome 17q22 involving C17orf112 and KIP2B genes, which have not yet been associated with a clinical phenotype. It is therefore unclear if her phenotype is partially explained by the chromosomal gain. Clinicians should suspect a contiguous gene deletion syndrome in a patient with Carney Complex and atypical features. Patients with this condition have also been described as “Carney Complex-plus”, a term that we do not recommend be used.

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<![CDATA[SUN-141 Altitude as the Second Hit on the Appearance of Paragangliomas]]> https://www.researchpad.co/article/elastic_article_8769 Paragangliomas are rare neuroendocrine tumors with a high degree of inheritance. These neoplasms arise from the extra-adrenal autonomic paraganglion and can secrete catecholamines. Many patients debut with symptoms of hypertensive crisis, tachycardia, dyspnea, headache and intense sweating. However, many tumors that are derived from the parasympathetic system are asymptomatic. Supported on the genetic basis are classified into two conglomerates: conglomerate I are those that have mutations and alter the response to hypoxia. Cluster II has a more syndromatic component, with alteration in the function of complex signaling pathways. A study based on histopathological diagnoses was carried out between 2007 and 2017 at a hospital in Bogotá (Colombia) 2600 meters above sea level, which documented 108 cases of paragangliomas that were predominantly located at the carotid level (76%), with a 4.7:1 ratio between women and men. 93.2% of the patients came from geographical locations with heights above 2,500m above sea level. Most of the tumors were asymptomatic. We draw attention to the fact that paragangliomas are probably more frequent than clinically diagnosed and the influence of the environment on the development of these tumors is highlighted, with a special contribution of oxygen pressure as a second event that contributes to the formation of the tumor.

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<![CDATA[MON-903 Sporadic Phaeochromocytoma, Pancreatic Neuroendocrine Tumour and a Sacral Hibernoma: A Case Report]]> https://www.researchpad.co/article/elastic_article_8758 Most phaeochromocytomas and pancreatic neuroendocrine tumours are sporadic in nature however the presence of multiple neuroendocrine tumours raises the suspicion of a hereditary endocrinopathy. Hibernomas, benign tumours that morphologically resemble brown fat, do not possess a clear aetiology and a link with other neuroendocrine tumours remains unclear. We report an unusual case of a concurrent sporadic phaeochromocytoma, pancreatic neuroendocrine tumour and a sacral hibernoma. A 61 year old female presented with a 3 month history of abdominal pain which led to the discovery of a lesion in her right adrenal gland and a soft tissue mass at the pancreatic tail on a CT Abdomen. The adrenal lesion was biochemically suggestive of a phaeochromocytoma (plasma normetanephrine 4930 pmol/L, plasma 3-methoxytyramine 580 pmol/L, urinary noradrenaline 5564 pmol/day, urinary dopamine 4720 nmol/day). A 68Ga-DOTATATE-PET-CT scan revealed DOTATATE avid lesions in the right adrenal gland, tail of pancreas and right sacral ala. Following preoperative medical therapy, the patient underwent a right adrenalectomy and a resection of the distal pancreatic lesion.Histopathology confirmed a phaeochromocytoma with no conscipicouous mitotic activity, and the pancreatic tail lesion was consistent with a well-differentiated neuroendocrine tumour (NET) (Ki-67 score <3%). Following normalisation of the serum catecholamines, a biopsy of the sacral lesion was undertaken, which returned positive for a hibernoma. Genetic testing revealed no identifiable genetic mutations.This case reports the synchronous presence of a phaeochromocytoma, pancreatic NET and sacral hibernoma with no identifiable genetic mutation. To date, the association between hibernomas and neuroendocrine tumours has not been fully established, but a few case reports suggest a possible association between MEN1 and hibernomas.

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<![CDATA[SUN-136 Clinico-Pathological Features, Treatment Modalities and Survival of Patients with Malignant Insulinoma: A Multicenter Study]]> https://www.researchpad.co/article/elastic_article_8756 Introduction: management of malignant insulinoma is challenging due to the need to control both hypoglycemic syndrome and tumor growth. Literature data is limited to small series.

Aim of the study: to analyze clinical-pathological characteristics, treatment modalities and prognosis of patients with malignant insulinoma.

Materials and methods: Multicenter retrospective study on 31 patients (M 61.3%) diagnosed between 1988 and 2017.

Results: The mean age at diagnosis was 48 ± 15 years. In 5 cases (16.1%) the hypoglycemic syndrome occurred after 46 ± 35 months from the diagnosis of NET, in 26 (83.9%) cases it led to the diagnosis of NET, of which 11 cases (42.3%) with mean diagnostic delay of 32.7 ± 39.8 months. The majority ​​of the NET were G2 (70.8 %) and in the pancreatic body-tail (78.6%). The mean NET diameter was 41 ± 31 mm. Metastases were widespread in 40.7%, only hepatic in 37%, only lymph nodal in 18.5%..Surgical treatment was performed in 21/31 (67.7%) with hypoglycemic control in 42.9%. Except for 2 patients with curative surgery, the others underwent further different lines of therapies including somatostatin analogues (SA), Peptide Receptor Radionuclide Therapy (PRRT), everolimus, chemotherapy, TAE/TACE/RFA, radiotherapy. PRRT was performed in 14/31 (45.1%) with complete (42.9 %) or partial (50%) syndrome control.

The median follow-up was 60 months. The 5-year survival rate was 62%. The median overall survival (OS) was 40 months. No significant difference in OS was observed according to the site of primary tumour and its dimension. A trend towards increased survival was found according to grading (5-year OS 100% for G1, 77% for G2, 33% for G3). Patients with Ki-67 ≤ 10% had a significant higher survival rate compared to patient with Ki-67 >10% (5-year OS rate 87% vs 43%, p: 0.03). As regards the type of treatment, patients who underwent surgery had a higher survival rate than those who did not (5-year OS 76% vs 31.7%, p= 0.006). Moreover, patients receiving PRRT as II line treatment had a better prognosis than those who underwent it in further lines, although the 5-year OS was not significantly different (80% vs 25% respectively, p=0.057).

Conclusions: Our study includes the largest series of patients with malignant insulinomas up to now reported. The hypoglycemic syndrome may occur after years in initially non-functioning NETs, or be misunderstood with delayed diagnosis of NETs. Surgical treatment and Ki67 <10% are prognostic factors associated with better survival. PPRT seems to be promising in the control of hypoglycemic syndrome.

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<![CDATA[SUN-917 Aggressive De Novo MEN1 Variant in a Child with Metastatic Pancreatic Acth and Crh Co-Secreting Neuroendocrine Tumor: Diagnosis and 10-Year Follow Up]]> https://www.researchpad.co/article/elastic_article_8753 Background:

In Multiple Endocrine Neoplasia type 1 (MEN1) only about 2% of pituitary adenomas are ACTH-secreting. Cushing Syndrome due to ectopic ACTH or CRH secretion from neuroendocrine tumors (NETs), carcinoid tumors, or pheochromocytomas is very rare, though patients with MEN1 are at increased risk for these three types of tumors, as well as autonomous adrenal secretion of cortisol. The 10-year follow up of a previously-reported case of a child with MEN1 and metastatic pancreatic ACTH/CRH-secreting NET is presented.

Clinical Case:

A previously-reported (J Clin Endocrinol Metab, 2015) now 21 yo female presented to the National Institutes of Health (NIH) at 11 yo with persistent hypercortisolemia despite transsphenoidal surgery for suspected Cushing Disease. However, the resected tissue revealed pituitary hyperplasia, and she remained hypercortisolemic. A CRH test was consistent with an ectopic source, and abdominal CT, PET scan, and Octreotide scan revealed a mass in the pancreatic tail. The patient underwent partial pancreatectomy at 11 yo with the resected tissue staining positive for ACTH and CRH. However, she remained hypercortisolemic, so bilateral adrenalectomy was performed. At 12 yo metastases were found, so Octreotide therapy was initiated. She continued to have elevated ACTH levels > 1000 pg/mL (5-46).

Additionally, a pituitary adenoma was noted at 12 yo, which has since increased in size. The patient also developed mild primary hyperparathyroidism, first noted at 19 yo. Sequencing of MEN1 for the patient and her parents revealed a de novo heterozygous c.1546dupC variant, consistent with sporadic MEN1. The patient also had a chromosome 8p23.2 duplication that was present in unaffected relatives.

Conclusion:

While 2% of patients with MEN1 may develop Cushing Syndrome due to an ACTH-secreting pituitary adenoma, it is also important to consider ectopic secretion of ACTH/CRH from MEN1-associated NETs, carcinoid tumors, or pheochromocytomas, as well as autonomous adrenal secretion of cortisol. Given the early age and severe presentation of MEN1 features in this patient, the c.1546dupC heterozygous variant of MEN1, which has been previously reported in multiple other cases of MEN1, may represent a higher-risk causative variant of MEN1. Alternatively, expression of this variant may have been affected by the concurrent presence of an otherwise apparently benign chromosomal variant.

References:

A. Karageorgiadis, G. Papadakis, J. Biro, M. Keil, C. Lyssikatos, M. Quezado, M. Merino, D. Schrump, E. Kebebew, N. Patronas, M. Hunter, M. Alwazeer, L. Karaviti, A. Balazs, M. Lodish, and C. Stratakis. Ectopic Adrenocorticotropic Hormone and Corticotropin-Releasing Hormone Co-Secreting Tumors in Children and Adolescents Causing Cushing Syndrome: A Diagnostic Dilemma and How to Solve It. Clin Endocrinol Metab, January 2015, 100(1):141–148

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<![CDATA[SUN-905 A Case of Adrenal Cushings a Primary Hyperparathyroidism]]> https://www.researchpad.co/article/elastic_article_8714 We present the case of a 31 year old female referred with weight gain, secondary amenorrhea, facial plethora and buffalo hump x6-9/12. Background medical history of caesarean section. She was on no regular medications. She rarely consumed alcohol. There was no relevant family history.

She experienced secondary amenorrhea x6/12. Her menarche was at the age of 14 and had regular periods thereafter. She had gained 13kg over the previous 9/12. Examination revealed an intrascapular fat pad, abdominal striae and facial plethora. Her BP was 150/87.

Initial investigations were as follows: Overnight DST: Cortisol 642 nmol/L, DHEAS <0.4 µmol/L, hCG <1 U/L, TSH 0.71 mIU/L, FT4 15.1 pmol/L, Prolactin 380 mIU/L, IGF-I 152 µg/L, FSH 4.4 IU/L, LH 3.0 IU/L, oestradiol <100 pmol/L, 17-OH Progesterone <1.0 nmol/L. She then underwent a low dose 48 hour dexamethasone suppression test the results showed: Cortisol Day 1(time 0) 704 nmol/L, Day 2 (time 24 hours) 702nmol/L, Day 3 (time 48 hours) 703 nmol/L and paired ACTH 1.4ng/L.

She was admitted from clinic with BP 189/107 and was started on metyrapone and ramipril. On this admission her bloods showed calcium 2.70 mmol/L, iPTH 113.5 ng/L, 25 (OH) D27nmol/L. Ct abdomen and pelvis revealed a 3.3x2.2 cm right adrenal lesion with hounsfeld units <10 and unremarkable left adrenal. ARR, plasma metanephrines and HbA1c were all normal. The case was discussed at MDM and referred for retroperitoneal laprascopic right adrenalectomy. She was discharged day 2 post op off anti hypertensives and on hydrocortisone 10mg/5mg/5mg. Histology confirmed adrenocortical adenoma and Ki67 <5%.

Synacthen test done one month post operatively showed time 0 cortisol 35 nmol/L, time 30 cortisol 56 nmol/L, time 60 cortisol 60 nmol/L and time 0 ACTH 51 ng/L. Post operatively her menses returned.

When vitamin D replete, we re-evaluated her hypercalcemia. This revealed 2.77 mmol/L, iPTH 100.7ng/L, calcium: creatinine ratio 0.72 mmol/mol. She had an ultrasound neck and sestamibi which both lateralised to right lower lobe of thyroid. A synacthen test was repeated which revealed time 0 cortisol 183 nmol/L and ACTH 44 ng/L, time 30 cortisol 258 nmol/L and time 60 cortisol 302 nmol/L. She was referred for 4 gland exploration with intra operative PTH. Her baseline intra operative PTH was 193 ng/L and her 10 minute post excision value was 55 ng/L which demonstrates a 65% drop in concentration and intra operative PTH returned to within the reference interval.

The histology was atypical displaying extension of the tumour through the capsule and possible vascular extension. Ki 67 was <2%. It has been sent to St. Guy’s and Thomas’ for a second opinion. Her calcium and iPTH returned to normal post operatively. MEN1 and CDKN1B genes were negative. We’re awaiting gene sequencing on the following - RET, CDC73, CASR, CDKNIA, CDKN2C AND CDKN2B. This case represents a case of multiple endocrinopathies with no found genetic link.

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<![CDATA[MON-911 Debilitating Neuropsychiatry Symptoms in Pancreatic Insulinoma Co-Secreting Serotonin and IGF-1]]> https://www.researchpad.co/article/elastic_article_8712 Background:

Insulinoma is the most common type of functioning pancreatic neuroendocrine tumor (NET). Polyhormonal secretions from the NET, giving rise to distinct clinical symptoms such as carcinoid symptoms are rare. Clinical Case: We report a 68-year-old woman who presented with four months history of recurrent diaphoresis, palpitations, tremors and chest tightness. These were associated with episodic paroxysms of flushing and diarrhoea. The physical examination was unremarkable. She was a well-nourished woman with BMI of 28 kg/m2. Initial laboratory tests ruled out any renal, liver abnormalities with normal cortisol and thyroid function test. Further evaluation confirms insulin mediated hypoglycaemia with low random blood sugar 2.5 mmol/l (4.4-7.8) and failure to suppress C-peptide, 1092 pmol/L (298-2350) and insulin levels, 12.7 mU/L (3-25). Urine 5-HIAA was markedly elevated 2430.37 µmol/day (3.66-42.89) with borderline elevation of serum chromogranin A level 122 ng/mL (27-94). IGF-1 was also raised at 416 ug/L (91-282). Two months later she presented with new onset of delirium, incoherence, agitation and restlessness independent of her hypoglycaemic events. These symptoms deteriorated and fluctuates throughout the day with period of normalcy in between. This has led to requirement of a full time caregiver for her. Cranial CT excluded any brain pathology. We are faced with a diagnostic challenge to localize the primary lesion as radiological imaging so far were normal. GALLIUM-68 PET CT showed physiological uptake in the uncinate process of the pancreas (SUVmax 14.4). Endoscopic ultrasound of the pancreas was normal. An intra-arterial calcium stimulation test with hepatic venous sampling (ASVS) confirms a lesion at the head of pancreas with two times increment of insulin from baseline at the gastroduodenal artery distribution. Despite elimination of hypoglycaemic events with Diazoxide 100mg twice daily, her neuropsychiatric symptoms persisted. We postulate that this might be from excessive peripheral production of serotonin by the pancreatic carcinoid tumour or a niacin deficiency state because of metabolic diversion of its precursor, tryptophan. Conclusion:

This case highlights the occurrence of debilitating neuropsychiatry manifestations in a likely neuroendocrine tumour arising from the head of pancreas secreting insulin, serotonin and IGF-1.

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<![CDATA[SUN-LB24 Clinical Performance of Multiplatform Mutation Panel MicroRNA Risk Classifier in Indeterminate Thyroid Nodules]]> https://www.researchpad.co/article/elastic_article_8653 Introduction: We evaluated the clinical performance of an expanded mutation panel in combination with microRNA classification (MPTX) for the management of indeterminate thyroid nodules. Methods: MPTX included testing of fine needle aspirates with a combination of ThyGeNEXT® mutation panel for strong and weak driver oncogenic changes and ThyraMIR® microRNA risk classifier. MPTX test status (positive or negative) and MPTX clinical risk classifications (low, moderate, or high risk) were determined blind to patient outcomes. Surgical pathology and clinical follow-up records of patients from multiple centers were used to determine patient outcomes. MPTX performance was assessed by Kaplan Meier analysis for cancer-free survival of patients, with risk of malignancy determined by hazard ratios (HR). Results: Our study included 140 patients with AUS/FLUS or FN/SFN nodules, of which 13% had malignancy. MPTX negative test status and MPTX low risk results conferred a high probability (94%) that patients would remain cancer free. MPTX positive test status (HR 11.2, P<0.001) and MPTX moderate risk results (HR 8.5, P=0.001) were significant risk factors for malignancy, each conferring a 53% probability of malignancy. MPTX high risk results elevated risk of malignancy even more so, conferring a 70% probability of malignancy (HR 38.5, P<0.001). Conclusions: MPTX test status accurately stratifies patients for risk of malignancy. Further classification using MPTX clinical risk categories enhances utility by accurately identifying patients at low, moderate, or high risk of malignancy at the low rate of malignancy encountered when clinically managing patients with indeterminate thyroid nodules.

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<![CDATA[MON-912 Undiagnosed Chronic Eczema as a Presentation of Glucagonoma in MEN 1 Syndrome]]> https://www.researchpad.co/article/elastic_article_8641 Background: Glucagonomas are pancreatic tumors arising from the islets cell of Langerhans that over secrete glucagon. Necrolytic migratory erythema (NME) is an important feature for the recognition of glucagonomas. Glucagonomas occurring in MEN1 is infrequent and seen in less than 3% of all glucagonomas.

Clinical Case: A 51-year-old male presented to the clinic multiple visits for rash affecting the legs and genital area of two months. His medical history include type 2 DM and HT. The rash was attributed to subacute eczema and treated with topical steroids but showed no improvement. The skin eruption initially appeared on lower extremities progressed to trunk, and face. The skin lesions were associated with weight loss and stomatitis. On physical examination, skin showed ill-defined erythematous plaque exhibiting annular pattern, scale, and erosion on all extremities and perioral area. When the skin lesions healed, the new cutaneous eruptions occurred. Laboratory testing revealed plasma glucose of 185 mg/dL. The skin biopsy reported vacuolated keratinocytes in the epidermis with eosinophil cytoplasm, compatible with NME leading to further workup for pancreatic tumor. CT abdomen revealed tumor mass 9.6x6 cm at the pancreatic tail and multiple nodules in the liver. Somatostatin receptor scintigraphy showed an area of increased radiotracer uptake at the tail of the pancreas and multiple liver nodules corresponding to the previous CT scan. Serum glucagon was 923 pg/mL, confirming the diagnosis for glucagonoma. The patient was treated with distal pancreatectomy, and enucleation of liver metastases. Histopathological reported grade 2 well-differentiated NET. During the admission, the patient was found to have a parathyroid level of 79.3 pg/mL and increased uptake in the left and right lower regions of the thyroid gland from parathyroid MIBI scan, indicating hyperfunctioning parathyroid glands. All pituitary hormones were within normal ranges and no pituitary tumor was detected by the MRI brain. BMD showed osteoporosis at the lumbar spine and left femoral neck. The patient was referred to general surgery for subtotal parathyroidectomy. Pathological of resected parathyroid glands reported parathyroid hyperplasia. Postoperative PTH level and calcium were returned to normal range. Genetic testing focused on MEN1 gene, and the mutation was identified. After four months follow up plasma glucagon decreased to 425 pg/dL, patient had complete resolution of the cutaneous lesions.

Conclusion: Glucagonomas are a rare pancreatic tumors and often difficult to recognize. Chronic eczema may misdiagnose for NME and delay diagnosis. NME can be challenging for physicians to recognize NME which is an important key to diagnose glucagonoma. Even though MEN1 association with glucagonoma is infrequent, awareness of such is important to allow appropriate testing for MEN1 in patients with glucagonoma.

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<![CDATA[SAT-LB26 A Dual Role for IGF-1R in Mammary Tumorigenesis]]> https://www.researchpad.co/article/elastic_article_8586 The insulin-like growth factor type 1 receptor (IGF-1R) is now thought to have a dual function in breast cancer. Several studies have shown overexpression of the IGF-1R pathway results in increased tumor cell proliferation and survival. Recent loss-of-function models have shown decreased mammary tumorigenesis latency and increased metastasis. These recent studies correlate with analyses of human patient datasets identifying worse overall survival with low IGF-1R expression. Similarly, inhibition of IGF-1R in the clinic has had no affect or has led to worse outcomes supporting the hypothesis that the IGF-1R may have tumor suppressive properties. Our prior published studies revealed loss of IGF-1R function results in heightened tumor epithelial stress, which alters the tumor microenvironment to be permissive for metastasis. Therefore, we asked does the loss of IGF-1R inherently change the tumor epithelium or is it simply the alterations of the microenvironment that lead to a metastatic primary tumor? We first analyzed cell invasion of primary tumor epithelial cells from a mouse tumor model driven by the Wnt1 oncogene (MMTV-Wnt1) and with reduced IGF-1R signaling by expression of a dominant-negative transgene (MMTV-dnIGF-1R). Epithelial cells from the MMTV-Wnt1/dnIGF-1R (bigenic) tumors invaded at the same rate as MMTV-Wnt1 tumor epithelial cells by tail vein injection suggesting invasive capacity is unchanged with reduced IGF-1R signaling. Interestingly, size of lung micrometastases from tail vein injected bigenic tumor epithelial cells was significantly reduced and the number also decreased over time in part due to a proliferative defect determined by immunostaining for pH3. Similarly, bigenic primary tumor epithelial cells injected into the mammary gland fat pad failed to form tumors suggesting alterations in cell adhesion. Consistent with this observation, E-cadherin gene and protein expression were decreased in the bigenic tumor epithelium compared to MMTV-Wnt1 tumors. In vitro analysis of cell adhesion in MMTV-Wnt1 primary epithelial cells resulted in both K8+ (luminal) and K14+ (basal) tumor epithelial cells adherence, while only K14+ cells from bigenic tumors adhered to collagen. Similarly, the lung micrometastases from tail vein injections exhibited predominantly K14+ cells. Analysis of MMTV-Wnt1 and bigenic primary tumors using single cell RNAseq revealed alterations in both stromal and epithelial populations that may contribute to bigenic primary tumor growth and metastasis. These data support the conclusion that inhibiting IGF-1R signaling results in both alterations to the tumor epithelium (partial EMT) and microenvironment that result in metastasis, but also, that the IGF-1R deficient metastatic cells need a niche or paracine signaling to proliferate.

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<![CDATA[MON-918 Familial Paraganglioma: Familiar Case Report]]> https://www.researchpad.co/article/elastic_article_8583 Introduction: Pheochromocytomas and Paragangliomas (PGL) are rare tumors originating from chromaffin cells. They may be sporadic or associated with familial inherited genetic syndromes around 50-80%. There are several PGL syndromes, the most common being PGL 1 (SDHD mutations), PGL 2 (SDHAF), PGL 3 (SDHC), PGL 4 (SDHB), PGL 5 (SDHA), PGL 6 (SLC25A11) and PGL 7 (DLST). SDHB mutations generate a higher probability of malignant PGL, as well as risk of renal, GIST and pituitary neoplasms. We report the case of a patient with a positive family history for the autosomal dominant SDHB mutation.Clinical cases: FZR, male, 19 years old, history of headache, sweating, palpitations, and sudden onset tremors associated with hypertensive peaks. Physical examination: Blood Pressure 140x90mmHg lying down, 110x70 standing up. Performed examinations, of which altered, showed: Plasma metanephrines: 82 pg/mL (RV <65), Plasma normetanephrines: 1.488pg/mL (VR <196), Urinary Catecholamines: 1.784mcg/24h (RV: 80-500), Abdomen Resonance showed an expansive, solid, heterogeneous abdomen mass in posterior contact with the left psoas muscle, medial with the aorta, and lateral with jejunum loops, measuring 7x3.5 cm. MIBG scintigraphy: abnormal uptake in left kidney. Family history: uncle diagnosed with cervical paraganglioma with cervical lymph node metastasis, gastric GIST and PCR genetic sequencing identifying mutation in SDHB (Q.137 G > T in exon 2). Asymptomatic second cousin with positive genetic analysis for the same mutation and another deceased first cousin diagnosed with pheochromocytoma with bone metastasis. He underwent tumor resection that identified retroperitoneal paraganglioma with 10% KI67, Protein S-100, Chromogranin-A and Synaptophysin positive. Carried out PCR genetic analysis that identified the same Q.137 G > T mutation in exon 2 of the SDHB gene in heterozygosis.Twenty-six relatives were called for mutation research, of which 5 positive for the SDHB mutation, until now, including the patient’s mother and twin brother, both already investigating related diseases.We await new family members and, subsequently, the result of the mutation analysis to continue the clinical and laboratory follow-up of this family.Conclusion: Although rare, this condition should be remembered as a differential diagnosis of diseases with such clinical symptoms and, once characterized, investigate possible associations with genetic syndromes.

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<![CDATA[SAT-148 Ectopic ACTH Secretion Has Varied Presentation and Requires Individualized Treatment - One Size Does Not Fit All]]> https://www.researchpad.co/article/elastic_article_8565 Ectopic ACTH secretion (EAS) presents in myriad ways. We present five cases of EAS to highlight similarities and differences in presentation and treatment. The first woman with known metastatic lung neuroendocrine tumour (NET) for two years presented with facial fullness, proximal weakness, worsening hypertension and hypokalaemia. Random cortisol of 2742nmol/L (99.39mcg/dL), with adrenocorticotrophic hormone (ACTH) of 201ng/L (5-50), was in keeping with EAS. She received medical treatment followed by bilateral adrenalectomy with EAS resolution and development of adrenal insufficiency. She is doing well. The second woman with proximal weakness was evaluated by neurologists. All neurological tests were normal but facial fullness and easy bruising was noted. Random cortisol was 875nmol/L (31.71mcg/dL) and ACTH was 90 ng/L. Imaging revealed metastatic liver disease with unknown primary and biopsy confirmed NET. Cortisol rose despite medical treatment and she died within fifteen months. The third woman with significant smoking history presented with haemoptysis and breathlessness. A right lung mass was suspected on chest X-ray and confirmed with CT. Endobronchial ultrasound-guided biopsy revealed small cell lung cancer (SCLC). She developed generalised weakness and severe hypokalaemia. Random cortisol of 1645nmol/L (59.63mcg/dL) with ACTH of 282ng/L suggested EAS. Despite medical treatment, she died within two weeks. The fourth woman presented with confusion, hypertension and severe hypokalaemia. Morning cortisol of 8557nmol/L (310.19mcg/dL) and random ACTH of 73ng/L were suggestive of EAS. CT demonstrated left lung mass with widespread metastases. She deteriorated and died within 2 weeks. Our only man had incidentally discovered metastatic liver lesions on ultrasound. Further imaging revealed prostatic mass and biopsy showed small cell neuroendocrine cancer. He presented with severe hypokalaemia. Random cortisol was 1065nmol/L (38.61mcg/dL) and ACTH was 188ng/L. He was commenced on medical treatment but declined rapidly and died.

All our patients had profound hypokalaemia and metastatic disease at presentation. Many patients do not exhibit classical cushingoid features as EAS tends to develop acutely and underlying malignancy drives weight loss. A high index of suspicion is required to make a diagnosis. EAS should be considered in patients with proximal myopathy, pigmentation, resistant or severe hypokalaemia or hypertension and known or suspected malignancy. Early and quick control of cortisol excess is essential to minimise cardiometabolic abnormalities, severe infections and thromboembolic complications. Prognosis depends upon age, frailty, comorbidity, nature of neoplasm and extent of hypercortisolaemia. Adrenolytics with or without bilateral adrenalectomy, reduction in tumour burden and management of complications are the mainstay of treatment.

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<![CDATA[SAT-LB308 Primary Hyperparathyroidism and Meningioma as a Part of Multiple Endocrine Neoplasm Type 1 (MEN Type 1)]]> https://www.researchpad.co/article/elastic_article_8561 Background: Meningioma is a rare association of Multiple endocrine neoplasia type 1 (MEN 1) and very few cases has been reported in literature. Clinical Case: a 75-year-old woman showed severe headache, disturbed consciousness and convulsions. A diagnosis of cerebral meningioma was made and surgical excision was done, histopathological examination confirmed meningioma; patient was transferred to the ICU postoperatively for monitoring. Patient’s consciousness was not regained in full and remained in delirium, follow up investigations revealed: serum calcium of 13.2 mg/dl (8.5 to 10.5 mg/dl), serum sodium 141 mmol/L (135-145 mmol/L) and potassium 4.9 mmol/L (3.5-5 mmol/L), serum parathormone of 850 pg/mL (10-65 pg/mL), primary hyperparathyroidism was suspected; further investigations revealed inferior parathyroid adenoma on ultrasound which elicited focal tracer uptake on sesta-mibi parathyroid scintigraphy. Patient did excision of the lesion and was confirmed by histopathological examination to be parathyroid adenoma. Patient recovered well postoperatively, consciousness was regained and no neurological defects ware present. Genetic studies where performed and was found positive for MEN type 1 gene. Whole body Ga-DOTATATE PET/CT was then done to exclude any associated tumors and no tracer uptake was found. Patient was discharged, family members were offered genetic analysis and were counselled on the importance of screening. Conclusion: MEN type 1 can rarely present with meningiomas with symptoms very similar and easily confused with hypercalcemia and the diagnosis can be missed.

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<![CDATA[MON-924 Susceptibility Genetic Testing and Functional Imaging Modalities in the Management of Bladder Paragangliomas]]> https://www.researchpad.co/article/elastic_article_8552 Introduction: Bladder Paragangliomas (PGLs) are rare neuroendocrine tumors derived from sympathetic paraganglionic tissue within the bladder wall, accounting for <1% of all Pheochromocytomas and Paragangliomas (PPGLs). >40% of PPGLs are associated with inherited syndromes through mutations affecting citric acid cycle enzymes (commonly SDH). Susceptibility gene identification has important implications for long-term care and facilitates targeted cascade genetic screening. Functional imaging using MIBG, Gallium DOTATATE and FDG-PET have become important tools in both diagnosis and treatment (Peptide Receptor Radionuclide Therapy).

Clinical Cases: We report the demographics, clinical characteristics and novel features of 7 patients with bladder PGLs. The series includes 2 females and 5 males, median age 38 years (range 14-68). 5 presented with hematuria and 2 were detected incidentally (1 found on radiological imaging and the other during cystoscopy surveillance). Other symptoms reported were headaches, sweating and palpitations which were relieved by urination. Only 1/7 had a known family history of PGLs. 5/7 patients had elevated plasma normetadrenaline levels and 2 had non-elevated catecholamine metabolites (these 2 patients were asymptomatic).

6/7 patients had genetic testing performed and pathogenic variants were identified in 4 (Fumarate hydratase (FH), SDHA, SDHB*2 genes) and no pathogenic variant identified in 2 patients in our genetic panel of 10 PPGL genes. All primary tumors demonstrated MIBG avidity and in 2 patients assessed there was PGL FDG-PET avidity. Metastatic disease was present in 2 patients (2 SDHB mutations; with 1 MIBG avid bone and 1 FDG-PET avid nodal metastasis). SDHB immunostaining on resected histology was available for 3 cases - absent SDHB immunostaining in the patient with SDHA mutation and strongly positivity in 2 patients (1 with no genetic mutation and in 1 with FH mutation).

Conclusions: The majority (>65%) of patients with bladder PGL have a germ line mutation in a susceptibility gene involving the citric acid cycle. An extended gene panel should be performed in all patients diagnosed with bladder PGLs including SDHA and FH gene mutations. SDH immunostaining of tumour can indicate SDHx gene defects but can be normal in FH mutations. SDHB is associated with increased risk of malignant/metastatic behavior. All 3 modalities of functional imaging (Ga DOTATATE, FDG PET, & MIBG) have a role in the assessment and treatment decision making in the management of bladder PGLs.

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<![CDATA[SUN-139 Luminescence-Based Drug Screen for Novel Androgen Receptor Antagonists for Prostate Cancer Therapy]]> https://www.researchpad.co/article/elastic_article_7193 The development and maintenance of the adult prostate is dependent on the action of androgens, which mediate its effect by binding to the androgen receptor (AR). Dysregulation in the AR signaling axis disrupts transcriptional homeostasis, shifting the balance towards uncontrolled proliferation and driving the progression towards prostate cancer (PCa). The prominent role of AR signaling in prostate carcinogenesis led to the development of androgen deprivation therapy (ADT) as the primary treatment strategy for managing PCa. Despite the success of ADT in early PCa cases, most patients develop resistance to ADT and the cancer ultimately recurs towards a lethal state termed castration-resistant prostate cancer (CRPC). Remarkably, AR signaling is still active in CRPC, suggesting that the progression towards CRPC is still reliant on AR activity. Current treatments are ineffective against CRPC, highlighting the need for alternative therapeutics that can combat the resistant nature of CRPC. To address the need for innovative approaches against CRPC, we used a robust luminescence-based bioassay that can identify novel AR antagonists. We screened plant extracts derived from local fauna by measuring their effect on AR-driven activity using a luciferase-based reporter assay in HeLa cells stably overexpressing hAR (HeLa-hAR). To identify candidate hits, HeLa-hAR cells were treated with DHT to induce AR-dependent luciferase activity, DHT with the AR antagonist bicalutamide as a positive control, and DHT plus the plant extracts. We identified one extract, A32, which showed significant inhibition of AR-dependent luciferase activity without having deleterious effects on cell viability. Secondary validation tests also showed that A32 exhibits a dose-dependent inhibition of AR-driven reporter activity. When testing the effect of A32 on gene expression in LNCaP cells, we observed a down-regulation in the expression of canonical AR target genes such as PSA to degrees similar to bicalutamide. These results suggest that A32 may be an AR antagonist or may target the AR signaling axis. Collectively, this study establishes the use of a luminescence-based reporter assay for the identification of novel AR antagonists from a plant extract library.

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<![CDATA[SUN-938 Rare Case of Ectopic Cushing Syndrome Caused by ACTH Secreting Thymic Neuroendocrine Tumor in a Patient with Multiple Endocrine Neoplasia Type 1]]> https://www.researchpad.co/article/elastic_article_7192 Introduction

Cushing syndrome (CS) represents an uncommon manifestation of MEN1 and can be caused by both ACTH dependent or independent etiologies. Among them, ectopic ACTH secretion from a Thymic neuroendocrine tumor (TNET) in MEN1 is rare, with very few cases reported so far in literature. We report a case of Ectopic Cushing syndrome (ECS) in a MEN1 patient (pt) with multiple tumors, secondary to ACTH-secreting TNET.

Case description:

A 44 year old male presented to our institution for nausea, vomiting, dizziness. He had initial workup which revealed multiple tumors (papillary thyroid cancer, thymic mass, parathyroid adenomas, bilateral adrenal nodules, macroprolactinoma, peripancreatic nodules). Given concern for MEN 1, genetic testing was performed which was confirmative. Hormonal workup at this time for adrenal nodules was negative including low dose dexamethasone suppression test(DST). The immobile thymic mass was found to be poorly differentiated NET on biopsy with Ki-67 >50% with vascular invasion and adhesions to lung/chest wall on VATS, not amenable to surgery. The pt declined chemotherapy and radiotherapy due to poor social support. Six months later, he presented with complaints of shortness of breath, proximal muscle weakness, anasarca. Evaluation revealed AM cortisol >60 ug/dL(range 6.7-22), high-dose DST Cortisol >60 ug/dL, 24hr urine free cortisol: 8511mcg (range 4-50) and ACTH level: 278pg/mL(range 6-50) confirming ACTH-dependent CS. Special stains from the previous TNET biopsy demonstrated positive staining for ACTH confirming ectopic ACTH secretion. Ketoconazole and chemotherapy with Etoposide and Carboplatin was started, however he clinically deteriorated and expired a few weeks after diagnosed of ECS.

Discussion:

TNET in MEN 1 is rare, with a prevalence of 3-8%. TNET are unusual neoplasms that account for 2% to 7% of all mediastinal tumors. TNET in MEN1 rarely secrete functional hormones with very few reported Ectopic ACTH secretion. MEN1 associated ECS from TNET is an aggressive disease with local invasion of adjacent mediastinal structures or metastasis being common, resulting in poor prognosis as demonstrated in few case reports including our case. Radical surgery of involved adjacent structures and adjuvant local RT can provide local disease control.

Conclusion:

Our pt is a rare case of ECS from TNET in MEN1 with poor prognosis. A special feature of this case is that the patient had initial negative evaluation for hypercortisolemia, however 6 months later he presented with signs and symptoms of severe hypercortisolism, with evaluation confirming transformation into ACTH producing TNET. This conversion is very rarely found in literature and adds to the unique presentation of the case.

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<![CDATA[SAT-144 Cooperative Mechanism of SREBP-Dependent Cholesterol Synthesis Pathway and P53 on Malignant Formation in Breast Cancer]]> https://www.researchpad.co/article/elastic_article_7149 p53 is mutated more than half of human cancers, and mutant p53, a gain of function, can actively have functional consequences with tumorigenesis. However, its action of molecular mechanisms, particularly in vivo conditions, has not been fully are clarified. Here, we generated KO and KI (R280K) breast cancer cell lines for p53 using CRISPR/Cas9 system, and then performed a three-dimensional culture model. We found that the introduction of mutant p53 was solely able to mediate the transformation to poor architectural structure. Interestingly, our findings in statin-effect along with cholesterol synthesis pathway, especially isoprenoid dependency, revealed that this pathway is necessary and sufficient for the regulation of malignant architecture in SREBP2-dependent manner with cooperatively being controlled by mutant p53 on 3D-cultured breast cancer. Furthermore, in accordance with the malignancy progresses, SREBP2 was accumulated in nuclear and nuclear membrane portion with enhancement in malignant formation. In addition, we found that mutant p53 interacts with SREBP2, and consistently mutant p53 was associated with DHCR7 promoter in parallel with binding pattern of SREBP2. Thus, our results provide the novel insight into the mutant p53, a gain of function, and its linkage to poor architectural structure in 3D-cultured breast cancer cells via SREBP2-dependent isoprenoids regulation as potential therapeutic targets.

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