GH-secreting Pituitary Tumors Research Articles

Differential Impact of Medical Therapies for Acromegaly on Glucose Metabolism.

Acromegaly is a rare endocrine disorder caused by excessive growth hormone (GH) production, due, in the vast majority of cases, to the presence of a GH-secreting pituitary tumour. The chronic elevation of GH and the resulting high circulating levels of insulin-like growth factor-1 (IGF-1) cause the characteristic tissue overgrowth and a number of associated comorbidities, including several metabolic changes, such as glucose intolerance and overt diabetes mellitus (DM). Elevated GH concentrations directly attenuate insulin signalling and stimulate lipolysis, decreasing glucose uptake in peripheral tissues, thus leading to the development of impaired glucose tolerance and DM. Acromegaly treatment aims to normalize plasma GH and IGF-1 levels using surgery, medical treatment, or radiotherapy. The effect of the different medical therapies on glucose homeostasis varies. This literature review explores the impact of the currently available pharmacological therapies for acromegaly (first- and second-generation somatostatin receptor ligands, a GH receptor antagonist, and dopamine agonists) on glucose homeostasis. We also discuss the underlying biological mechanisms through which they impact glucose metabolism.

Digital quantification of somatostatin receptor subtypes 2 and 5 in growth hormone-secreting pituitary tumors.

Immunohistochemistry (IHC) of somatostatin receptor subtype 2 can predict response to first-generation somatostatin receptor ligands (fg-SRLs) in acromegaly. Recently, we validated an open-source digital image analysis (DIA) to quantify somatostatin receptor subtype 2 (SSTR2) expression. We aimed to validate the DIA also on somatostatin receptor subtype 5 (SSTR5) in a new cohort of growth hormone (GH)-secreting pituitary tumors, with IHC performed in a different laboratory, and to correlate fg-SRL response with SSTs expression. Somatostatin receptor subtype 2 and SSTR5 were assessed in 42 GH-secreting pituitary tumors, using a semiquantitative immunoreactivity score (IRS) and the DIA by use of the open-access software CellProfiler. The DIA calculates the staining intensity and the percentage of positive cells (%PC). We found a good correlation between IRS and DIA for both SSTR2 and SSTR5 (P < .001), demonstrating the reliability of the DIA in this setting. Response to fg-SRL treatment correlated with SSTR2, but not SSTR5, expression. Somatostatin receptor subtype 2 expression predicted response to fg-SRL. In particular, the identified cut-offs were IRS ≥ 5 (area under the curve [AUC] 0.763; sensitivity 77%; specificity 83%); intensity/area ≥0.106 (AUC 0.833; sensitivity 92%; specificity 83%); and %PC-DIA ≥63.7% (AUC 0.917; sensitivity 92%; specificity 83%). The SSTR2 %PC correlated with treatment response only when evaluated using the DIA, showing a better performance of this method.

7248 Spliceosome component TCERG1 regulates the aggressiveness of somatotroph adenoma

Abstract Disclosure: K. Kim: None. The role of the spliceosome in the development of pituitary tumors is not well understood, despite preliminary studies indicating abnormal expression of oncogenic splicing variants in these neuroendocrine tumors. We aimed to identify differentially expressed spliceosome components in growth hormone (GH)-secreting pituitary tumors and investigate their roles in pathogenesis.We performed transcriptome analysis of 20 somatotroph adenomas and 6 normal pituitary tissues to select dysregulated spliceosome components. Clinical characteristics were analyzed based on gene expression in 64 patients with acromegaly. GH secreting pituitary adenomas were confirmed by 75 g oral glucose tolerance and immunohistochemical staining. Proliferation, invasion, and hormonal activity of GH secreting pituitary adenoma cells were investigated after modulating gene expression.TCERG1 expression was significantly higher in somatotroph adenomas than in normal cells (log2 fold change 0.59, adjusted P=0.0002*). Genotype-phenotype analysis revealed that patients with higher TCERG1 expression had lower surgical remission rates than those with lower expression (63.64% vs. 95.45%, P=0.009*). TCERG1 expression was significantly higher in groups with cavernous sinus (CS) invasion or Ki67 index over 1.5 (2.06 vs. 1.65, P=0.011*; 2.02 vs. 1.66, P=0.043*). TCERG1 overexpression led to a 16.91% increase in proliferation after 72 h (P&amp;lt;0.001*) and a 249.47% increase in invasion after 48 h in GH3 cells (P=0.026*). Conversely, TCERG1 silencing significantly decreased cell proliferation (10.15% at 72 h, P&amp;lt;0.001*) and invasion (96.87% at 48 h, P=0.029*). Vimentin was increased, but E-cadherin was decreased in both TCERG1 overexpressed GH3 cells and somatotroph adenomas. And TCERG1 silence reversed the expression of the genes (CDH2, SNAI1, ZEB2, and VIM) in GH3 cells. Additionally, GH secretion increased when TCERG1 was overexpressed in GH3 cells. Spliceosome machinery provide novel insights into the pathogenesis of GH-secreting pituitary tumor and highlight the potential role of TCERG1 as a therapeutic target. Presentation: 6/2/2024

12353 Differential Gene Expression And Pathway Analysis In Growth Hormone Secreting Pituitary Tumors According To Granulation Pattern

Abstract Disclosure: H. Shin: None. Differential gene expression and pathway analysis in growth hormone-secreting pituitary tumors according to granulation pattern. Hye Ju Shin [1], Kyung Won Kim[2], Chan Woo Kang[2], Eun Jig Lee[2], Cheol Ryong Ku[2]. [1]Department of Clinical Drug Discovery &amp; Development, Yonsei University College of Medicine, Seoul, Republic of Korea, [2]Endocrinology, Institute of Endocrine Research, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea Objective: The purpose of this research is to explain clinical variations in patients with acromegaly by exploring gene expression differences according to granulation patterns in growth hormone (GH)-secreting pituitary tumors. Materials &amp; methods: Transcriptome analysis was conducted on 6 normal pituitary tissues and 15 GH-secreting pituitary tumors, including 9 densely granulated somatotroph tumors (DGSTs) and 6 sparsely granulated somatotroph tumors (SGSTs). Results: The median age at diagnosis was 50 years, with a predominance of female patients (60%). We identified 3111 differentially expressed genes (DEGs) in tumors compared to normal pituitaries, with 1117 DEGs unique to a specific granulation within tumors. SGST showed enriched the pathways involved in neuronal development (axon development, axonogenesis, axon guidance, synapse and presynapse organization, gliogenesis, glial cell differentiation, nerve development, synaptic membrane adhesion, semaphorin-plexin signaling pathway involved in neuron projection guidance) and acute inflammatory response. No pathways were significantly downregulated in SGST compared with those in DGST. Three signaling pathways (JAK-STAT, phosphatidylinositol 3-kinase, and MAP cascade) and three neuronal development processes (generation of neurons, nerve development, and neurogenesis) were significantly enriched in both GO and GSEA analysis. The PPI networks constructed with the up- and downregulated DEGs consisted of 128 and 132 PPI pairs, respectively. There were 10 hub proteins, top highly connected DEGs: ANLN, TLE3, TLE2, DMD, ADRA1A, RBFOX1, MMP2, LMO1, RUNX1T1, and NPPA. Conclusion: The results indicate that granulation-specific gene expression may underpin diverse clinical characteristics in acromegaly. Overall, this study emphasizes the potential for further investigation into these transcriptomic variations and their roles in disease pathology, particularly the involvement of genes linked to neuronal development, inflammatory response, and JAK-STAT signaling in SGST. Presentation: 6/3/2024

Spliceosome component TCERG1 regulates the aggressiveness of somatotroph adenoma.

We aimed to identify differentially expressed spliceosome components in growth hormone (GH)-secreting pituitary tumors and investigate their roles in pathogenesis. We performed transcriptome analysis of 20 somatotroph adenomas and 6 normal pituitary tissues to select dysregulated spliceosome components. Clinical characteristics were analyzed based on gene expression in 64 patients with acromegaly. Proliferation, invasion, and hormonal activity of GH secreting pituitary adenoma cells were investigated. TCERG1 expression was significantly higher in somatotroph adenomas than in normal pituitaries (log2 fold change 0.59, adjusted P = 0.0002*). Genotype-phenotype analysis revealed that patients with higher TCERG1 expression had lower surgical remission rates than those with lower expression (63.64% vs. 95.45%, P = 0.009*). TCERG1 expression was significantly higher in groups with cavernous sinus (CS) invasion or Ki67 index over 3 (all P>0.05*). TCERG1 overexpression led to a 29.60% increase in proliferation (P<0.001*) and a 249.47% increase in invasion after 48h in GH3 cells (P = 0.026*). Conversely, TCERG1 silencing significantly decreased cell proliferation (25.76% at 72h, P<0.001*) and invasion (96.87% at 48h, P = 0.029*). E-cadherin was decreased, but vimentin was increased in both TCERG1 overexpressed GH3 cells and somatotroph adenomas. And TCERG1 silence reversed the expression of the genes (CDH2, SNAI1, ZEB2, and VIM) in GH3 cells. Spliceosome machinery provide novel insights into the pathogenesis of GH-secreting pituitary tumor and highlight the potential role of TCERG1 as a biomarker for tumor aggressiveness.

Differential gene expression and pathway analysis in growth hormone-secreting pituitary tumors according to granulation pattern.

This study investigated differential gene expression between granulation patterns in growth hormone (GH)-secreting pituitary tumors, aiming to elucidate novel transcriptomes that explain clinical variances in patients with acromegaly. Transcriptome analysis was conducted on 6 normal pituitary tissues and 15 GH-secreting pituitary tumors, including 9 densely granulated somatotroph tumors (DGSTs) and 6 sparsely granulated somatotroph tumors (SGSTs). We identified 3111 differentially expressed genes (DEGs) in tumors compared to normal pituitaries, with 1117 DEGs unique to a specific granulation within tumors. SGST showed enrichment of neuronal development and acute inflammatory response pathways, along with a significant enhancement of JAK-STAT, phosphatidylinositol 3-kinase, and MAPK signaling. The results suggest that granulation-specific gene expression may underpin diverse clinical presentations in acromegaly, highlighting the potential for further investigation into these transcriptomic variations and their roles in disease pathology, particularly the involvement of genes linked to neuronal development, inflammatory response, and JAK-STAT signaling in SGST.

Acromegaly in humans and cats: Pathophysiological, clinical and management resemblances and differences

ObjectiveAcromegaly is a disorder associated with excessive levels of growth hormone (GH) and insulin-like growth factor-1 (IGF-1). In general, GH/IGF-1 excess leads to morphologic craniofacial and acral changes as well as cardiometabolic complications, but the phenotypic changes and clinical presentation of acromegaly differ across species. Here, we review the pathophysiology, clinical presentation and management of acromegaly in humans and cats, and we provide a systematic comparison between this disease across these different species. DesignA comprehensive literature review of pathophysiology, clinical features, diagnosis and management of acromegaly in humans and in cats was performed. ResultsAcromegaly is associated with prominent craniofacial changes in both species: frontal bossing, enlarged nose, ears and lips, and protuberant cheekbones are typically encountered in humans, whereas increased width of the head and skull enlargement are commonly found in cats. Malocclusion, prognathism, dental diastema and upper airway obstruction by soft tissue enlargement are reported in both species, as well as continuous growth and widening of extremities resulting in osteoarticular compromise. Increase of articular joint cartilage thickness, vertebral fractures and spine malalignment is more evident in humans, while arthropathy and spondylosis deformans may also occur in cats. Generalized organomegaly is equally observed in both species. Other similarities between humans and cats with acromegaly include heart failure, ventricular hypertrophy, diabetes mellitus, and an overall increased cardiometabolic risk. In GH-secreting pituitary tumours, local compressive effects and behavioral changes are mostly observed in humans, but also present in cats. Cutis verticis gyrata and skin tags are exclusively found in humans, while palmigrade/plantigrade stance may occur in some acromegalic cats.Serum IGF-1 is used for acromegaly diagnosis in both species, but an oral glucose tolerance test with GH measurement is only useful in humans, as glucose load does not inhibit GH secretion in cats. Imaging studies are regularly performed in both species after biochemical diagnosis of acromegaly. Hypophysectomy is the first line treatment for humans and cats, although not always available in veterinary medicine. ConclusionAcromegaly in humans and cats has substantial similarities, as a result of common pathophysiological mechanisms, however species-specific features may be found.

Pegvisomant and pasireotide in PRL and GH co-secreting vs GH-secreting Pit-NETs.

The objective of the study was to evaluate the efficacy of second-line therapies in patients with acromegaly caused by a growth hormone (GH) and prolactin (PRL) co-secreting pituitary neuroendocrine tumor (GH&PRL-Pit-NET) compared to their efficacy in patients with acromegaly caused by a GH-secreting pituitary neuroendocrine tumor (GH-Pit-NET). This is a multicenter retrospective study of patients with acromegaly on treatment with pasireotide and/or pegvisomant. Patients were classified in two groups: GH&PRL-Pit-NETs when evidence of hyperprolactinemia and immunohistochemistry (IHC) for GH and PRL was positive or if PRL were >200 ng/dL regardless of the PRL-IHC and GH-Pit-NETs when the previously mentioned criteria were not met. A total of 28 cases with GH&PRL-Pit-NETs and 122 with GH-Pit-NETs met the inclusion criteria. GH&PRL-Pit-NETs presented at a younger age, caused hypopituitarism, and were invasive more frequently than GH-Pit-NETs. There were 124 patients treated with pegvisomant and 49 with pasireotide at any time. The efficacy of pegvisomant for IGF-1 normalization was of 81.5% and of pasireotide of 71.4%. No differences in IGF-1 control with pasireotide and with pegvisomant were observed between GH&PRL-Pit-NETs and GH-Pit-NETs. All GH&PRL-Pit-NET cases treated with pasireotide (n = 6) and 82.6% (n = 19/23) of the cases treated with pegvisomant normalized PRL levels. No differences in the rate of IGF-1 control between pegvisomant and pasireotide were detected in patients with GH&PRL-Pit-NETs (84.9% vs 66.7%, P = 0.178). We conclude that despite the more aggressive behavior of GH&PRL-Pit-NETs than GH-Pit-NETs, no differences in the rate of IGF-1 control with pegvisomant and pasireotide were observed between both groups, and both drugs have shown to be effective treatments to control IGF-1 and PRL hypersecretion in these tumors.

The value of digital quantification of somatostatin receptor subtypes 2 and 5 immunostaining in GH-secreting pituitary tumors

The value of digital quantification of somatostatin receptor subtypes 2 and 5 immunostaining in GH-secreting pituitary tumors

Differences in the efficacy of second-line therapies on the biochemical control of acromegaly in patients with GH secreting pituitary neuroendocrine tumors (Pit-NETs) and GH and PRL cosecreting Pit-NETs

Differences in the efficacy of second-line therapies on the biochemical control of acromegaly in patients with GH secreting pituitary neuroendocrine tumors (Pit-NETs) and GH and PRL cosecreting Pit-NETs

Endoscopic Transsphenoidal Surgery in Growth-Hormone Pituitary Adenomas (GH PitNETs): Current Indications, Limitations, and the Importance of a Multidisciplinary Approach.

Acromegaly and gigantism are rare diseases, usually caused by a growth hormone-secreting pituitary adenoma, recently renamed GH-secreting pituitary neuroendocrine tumor (GH-PitNET). The transsphenoidal approach is the mainstay of treatment, although a non-negligible number of patients require a multimodal approach with neo-adjuvant or adjuvant medical and radiation therapy. Understanding the clinical complexity of acromegaly and gigantism is essential to improve treatment safety and success. A multidisciplinary skilled team is required to provide adequate pre-operative evaluation and management of the comorbidities associated with GH-PitNETs. Specific intraoperative surgical and anesthesiologic challenges (i.e., mucosal and bone hypertrophy, reduced intracarotid distance, and tumor invasiveness) to ensure maximal and safe resection. The same is for postoperative management to provide precise tumor histological characterization to be used in association with clinical-radiological and biochemical data to tailor patient management in terms of acromegaly control and treatment/prevention of comorbidities. This paper critically revises the indications and limitations of endoscopic transsphenoidal surgery for GH-PitNETs, discusses the frequently complex preoperative evaluation of patients with acromegaly, and analyzes the challenging aspects of the disease, underling the importance of a multidisciplinary framework, which should include a dedicated team of surgeons (neuro- and ENT-), endocrinologists, radiologists, pathologists, and anesthesiologists.

FRI370 Hyperthyroidism And Acromegaly In A Patient With A Mature Plurihormonal PIT1 Lineage PitNET/Adenoma

Abstract Disclosure: D. Slack: None. A.C. Levine: None. Background: TSH- and GH-secreting pituitary neuroendocrine tumors (PitNETs) are both rare entities, with an incidence of 1 per million people and 1-4 per million people, respectively. Thyrotroph, somatotroph, and lactotroph cells have the same progenitor, regulated by the PIT1 transcription factor. Thus, it is not unusual for PIT1 positive tumors to exhibit immunhistochemical expression of TSH, GH, and prolactin. It is vanishingly rare, however, for these tumors to secrete multiple biologically active hormones with apparent clinical sequelae. We herein report on a case of a patient with a plurihormonal PIT1 lineage PitNET secreting prolactin with secondary amenorrhea, TSH causing central hyperthyroidism and GH resulting in acromegaly. Clinical Case: A 42-year-old woman with a 1-year history of amenorrhea presented with 3 months of progressive weight loss, fatigue, palpitations, and tremulousness. She was found to have central hyperthyroidism, with an elevated free T4 (&amp;gt;7.77 ng/dL, nl 0.82 – 1.77) and inappropriately normal TSH (3.25 uIU/mL, nl 0.45 – 4.5). Full endocrine workup confirmed central hyperthyroidism with elevated free T4 (5.02 ng/dL) and TSH (4.68 uIU/mL) and also demonstrated hyperprolactinemia (122 ng/mL, nl 4.8 – 23.3 ng/mL), elevated IGF-1 (795 ng/mL, nl 91 – 308 ng/mL), GH (19 ng/mL, nl 0 – 10) and free alpha subunit (28 ng/mL, nl &amp;lt;1.02). Over the ensuing 4 months, she noted enlargement of her lips, nose, feet, and hands. MRI demonstrated a pituitary macroadenoma measuring 2.2 cm x 2.7 cm x 2 cm with asymmetric extension into the left cavernous sinus and mild elevation of the adjacent optic chiasm. She underwent an uncomplicated transsphenoidal resection of the tumor with no residual tumor noted on post-op MRI. Discharge medications were hydrocortisone 10 mg AM and, 5 mg early afternoon and levothyroxine 50 mcg daily. One month postoperatively, labs were notable for a low TSH (0.16 mIU/L), normal free T4 (1.62 ng/dL), down-trending IGF-1 (339 ng/mL), and normal prolactin (15.1 ng/mL). Additionally, AM cortisol and ACTH levels remained normal after holding her morning dose of hydrocortisone. She reported resolution of all presenting symptoms of thyrotoxicosis as well as decreasing size of her hands, feet, and nose. Pathology revealed a mature plurihormonal PIT1-lineage PitNET, with immunoreactivity for PIT1, GH, TSH, and prolactin and MIB-1 index of 3%. Conclusion: This case demonstrates the potential for PitNETs to secrete multiple biologically active pituitary hormones, including prolactin, TSH and GH, highlighting the importance of maintaining an index of suspicion for pituitary causes in the evaluation of thyrotoxicosis and of considering the plurihormonal potential of PitNETs in patients presenting with multiple endocrinopathies. Presentation: Friday, June 16, 2023

Molecular characterization of epithelial-mesenchymal transition and medical treatment related-genes in non-functioning pituitary neuroendocrine tumors.

Different medical therapies have been developed for pituitary adenomas. However, Non-Functioning Pituitary Neuroendocrine Tumors (NF-PitNET) have shown little response to them. Furthermore, epithelial-mesenchymal transition (EMT) has been linked to resistance to medical treatment in a significant number of tumors, including pituitary adenomas. We aimed to evaluate the expression of EMT-related markers in 72 NF-PitNET and 16 non-tumoral pituitaries. To further explore the potential usefulness of medical treatment for NF-PitNET we assessed the expression of somatostatin receptors and dopamine-associated genes. We found that SNAI1, SNAI2, Vimentin, KLK10, PEBP1, Ki-67 and SSTR2 were associated with invasive NF-PitNET. Furthermore, we found that the EMT phenomenon was more common in NF-PitNET than in GH-secreting pituitary tumors. Interestingly, PEBP1 was overexpressed in recurrent NF-PitNET, and could predict growth recurrence with 100% sensitivity but only 43% specificity. In parallel with previously reported studies, SSTR3 is highly expressed in our NF-PitNET cohort. However, SSTR3 expression is highly heterogeneous among the different histological variants of NF-PitNET with very low levels in silent corticotroph adenomas. NF-PitNET showed an enhanced EMT phenomenon. SSTR3 targeting could be a good therapeutic candidate in NF-PitNET except for silent corticotroph adenomas, which express very low levels of this receptor. In addition, PEBP1 could be an informative biomarker of tumor regrowth, useful for predictive medicine in NF-PitNET.

PMON105 Giant Growth Hormone (GH)-Secreting Pituitary Tumor with Massive Sphenoid Sinus Invasion and Spontaneous Cerebrospinal Fluid (CSF) Leak: A Case Report

Abstract Introduction Giant pituitary tumor, defined as &amp;gt;4cm, comprise 6-10% of all pituitary tumors. Giant GH-secreting pituitary tumors are rare and difficult to treat. They typically invade surrounding structures ​such as the cavernous sinus, making ​complete resection challenging or impossible. This report highlights a case of giant GH-secreting pituitary tumor with an unusual clinical presentation.CLINICAL CASE: A 56 Y/O male with hypertension, cardiomyopathy, obesity, and OSA presented to the ER with stroke-like symptoms. Brain CT and MRI revealed small acute to subacute infarcts within the left occipital, left frontal, right frontal, right parietal areas, and right cerebellum. An incidental finding was a 4.3 cm T2 hyperintense enhancing mass centered within the skull base with involvement of the sella, extension into bilateral cavernous sinuses, clivus, encasement of bilateral carotid arteries, and invasion through the sphenoid sinus into the nasopharyngeal space resulting in a preoperative CSF. He was overtly acromegalic with coarse facial features, prominent frontal bossing, early prognathism, and macroglossia. Hands and feet were enlarged, but non-edematous. Visual field testing was normal. Laboratory values: IGF-1, 317 ng/mL (NL &amp;lt;170): GH, 4 ng/ml (NL&amp;lt;10); prolactin, 17.6 ng/mL (NL 2.5-17.4); total testosterone, 11 ng/dL (NL 130-810); free testosterone, 2 pg/dL (NL 36-146). ACTH stimulation produced a normal cortisol response. Test for AIP gene mutation was negative. Emergent packing of the CSF leak site was done. He underwent trans-sphenoidal (TSS) debulking of the tumor along with reconstruction of the ​skull base and repair of CSF leak. Postoperatively, IGF-1 level decreased to 216 ng/mL. Immunohistochemical stains of the tumor were strongly positive for GH and somatostatin receptor type2 (SSTR2). Three weeks postoperatively, IGF-1 increased to 482 ng/mL. IGF-1 level decreased to 326 ng/mL after 3 doses of lanreotide 90 mg/month. He will be now monitored on 120 mg/month. Currently, he requires only testosterone replacement. Conclusion This patient had the unique presentation of florid acromegaly and CSF leak mainly related to his delay in seeking medical care. Absence of visual defects has been noted in only 15% of reported patients with giant GH-secreting adenomas. Massive replacement of the sphenoid sinus by a giant pituitary tumor causing a CSF leak with invasion into the ​cavernous sinuses and clivus has been rarely reported. Trans-sphenoidal resection is the preferred first-line treatment for patients with acromegaly. The remission rate decreases and can reach almost 0% for giant GH-secreting tumors. Somatostatin receptor analogs (SRA) are the preferred first-line pharmacological treatment as an adjuvant therapy for residual tumor. Our patient likely will need continued SRA and potentially other modalities to control acromegaly due to unresectable tumor anatomy. This case also highlights the complications of delayed detection and benefits of extensive TSS surgical resection with the goal to enhance his response to SRA. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PMON322 Gigantism in 13-Year-Old Male With Pituitary Tumor

Abstract Background Pituitary gigantism is caused by excess growth hormone [GH] secretion from the pituitary gland when the growth plates are open leading to excessive linear growth and tall stature in the pediatric population. It is extremely rare with a reported incidence of 8 cases per million person-years. Clinical Case The patient is a 13-year-old male who presented with concerns of accelerated growth rate and tall stature. His father noticed the patient's tall stature when he passed his own height the last year. The patient was seen by his PCP who referred the family to pediatric endocrinology. His symptoms included snoring and bi-weekly headaches, but no vision changes. Review of his growth charts showed linear growth tracking at greater than the 95th percentile since the age of 9 years. His clinical features included large hands, large feet, prominent jaw, testicular volume &amp;gt;25 ml, tall stature [Ht &amp;gt; 99%, Z= +4.59 SD]. The patient's mid-parental height is 69.1 inches [175.5 cm] and the patient measured 76.6 inches [194.5 cm]. His predicted height was 7 feet 1.5 inches [217.2 cm] based on his bone age. His clinical features were strongly concerning for Gigantism. Initial labs showed IGF-1 of 924 ng/mL [168–576], prolactin of 20.1 ng/mL [2.8–11.0], and IGF-BP3 8.7 mg/L [3.1–9.5]. Cortisol, ACTH, TSH, FT4, LH, FSH, Testosterone were within normal limits. Bone age was concordant with chronological age. MRI showed enlarged pituitary gland measuring 1.3 cm in height, suspicious for macroadenoma. Cardiac evaluation including echocardiogram came back normal. GH suppression test resulted in a 2-hour GH level of 27.3 ng/mL [&amp;lt;1] and he was diagnosed with Gigantism due to GH-secreting pituitary tumor. The parents decided to consult neurosurgery team at a different facility, where transsphenoidal resection of the pituitary tumor was performed. He did not develop any postoperative complications, including Diabetes insipidus or any pituitary hormone deficiencies, and was discharged home shortly after. Follow-up MRI of the pituitary showed no evidence of residual tumor. Pathology of the macroadenoma expressed GH and prolactin on immunohistochemical stains and was negative for TSH, LH/FSH, and ACTH. Genetic studies obtained were negative, lowering the likelihood of inherited predisposition to endocrine neoplasms. The patient has remained well post-operatively and has been able to continue school and play basketball without issues. Conclusion Pituitary gigantism occurs in the pediatric population prior to skeletal epiphyseal closure and is caused by GH excess. Initial screening tests should evaluate for pituitary function including IGF-1 and prolactin levels. The gold standard for diagnosing GH excess is the GH suppression test. Even though rare, it is important for clinicians to keep a high level of suspicion for quick recognition and management of overgrowth syndromes. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Implications of the 2017 WHO classification in the characterization of GH-secreting pituitary tumors

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Evaluation of the expression of necroptosis pathway mediators and its association with tumor characteristics in functional and non-functional pituitary adenomas

BackgroundPituitary adenomas impose a burden of morbidity on patients and characterizing the molecular mechanisms underlying its pathogenesis received remarkable attention. Despite the appealing role of necroptosis as an alternative cell death pathway in cancer pathogenesis, its relevance to pituitary adenoma pathogenesis has yet to be determined that is perused in the current study.MethodsThe total number of 109 specimens including pituitary adenomas and cadaveric healthy pituitary tissues were enrolled in the current study. Tumor and healthy pituitary tissues were subjected to RNA extraction and gene analysis using Real-Time PCR. The expression levels of necroptosis markers (RIP1K, RIP3K and, MLKL) and their association with the patient’s demographic features were evaluated, also the protein level of MLKL was assessed using immunohistochemistry in tissues.ResultsBased on our data, the remarkable reduction in RIP3K and MLKL expression were detected in nonfunctional and GH-secreting pituitary tumors compared to pituitary normal tissues. Invasive tumors revealed lower expression of RIP3K and MLKL compared to non-invasive tumors, also the attenuated level of MLKL was associated with the tumor size in invasive NFPA. The simultaneous down-regulation of MLKL protein in pituitary adenoma tissues was observed which was in line with its gene expression. While, RIP1K over-expressed significantly in both types of pituitary tumors which showed no significant correlation with patient’s age, gender and tumor size in GHPPA and NFPA group. Notably, MLKL and RIP3K gene expression was significantly correlated in the GHPPA group.ConclusionsAccording to our data, the reduced expression of necroptosis mediators (RIP3K, MLKL) in pituitary adenoma reinforces the hypothesis that the necroptosis pathway can be effective in regulating the proliferation and growth of pituitary tumor cells and tumor recurrence.

Neutrophil-to-Lymphocyte, Platelet-to-Lymphocyte Ratios, and Systemic Immune-Inflammation Index as Potential Biomarkers of Chronic Inflammation in Patients with Newly Diagnosed Acromegaly: A Single-Centre Study

Acromegaly is a rare disease caused by overproduction of growth hormone (GH) by a pituitary adenoma, and consequently increased insulin-like growth factor 1 (IGF-1) concentration. The GH/IGF-1 axis and immune cells interactions are hypothesized to be involved in subclinical inflammation. This retrospective study aimed to investigate the differences in neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR) ratios, and systemic immune-inflammation index (SII) in GH-secreting adenomas compared with non-functioning pituitary adenomas (NFPAs) concerning clinical and radiological findings. After evaluation of 665 patients with pituitary tumors, 62 individuals with newly diagnosed acromegaly and 134 with NFPAs were enrolled in the analysis. The control group consisted of 120 healthy individuals. Fifty-eight patients with acromegaly were re-evaluated after medical or surgical therapies. NLR, PLR, SII values, and neutrophil count were significantly higher (p ≤ 0.001), whereas lymphocyte count was lower in acromegaly than in NFPAs (p = 0.001). No significant differences between NFPAs and controls were observed in analyzed ratios. Higher preoperative NLR, PLR, SII values were found in patients who failed to achieve a cure with surgery (p < 0.05). Although NLR, PLR, and SII values were significantly higher in acromegaly, these indices cannot be used to discriminate GH-secreting pituitary tumors from NFPAs. Treatment of acromegaly decreased the value of NLR and SII, but it requires further studies to consolidate the real clinical role of these inflammation-related ratios.

Novel somatic variants involved in biochemical activity of pure growth hormone-secreting pituitary adenoma without GNAS variant

We aimed to identify somatic genetic alterations in pure growth hormone (GH)-secreting pituitary adenomas without GNAS variants. Patients with GH-secreting pituitary adenoma who underwent transsphenoidal adenomectomy at Severance Hospital, Yonsei University College of Medicine were recruited. Somatic genetic alterations were profiled by whole-exome sequencing (WES) and targeted resequencing. WES was performed using DNA from nine GH-secreting pituitary tumors and corresponding blood samples. Absence of GNAS variant was confirmed by Sanger sequencing. For targeted resequencing of 140 fixed tissues, 48 WES-derived candidate genes and 7 GH-secreting pituitary adenoma-associated genes were included. Forty-eight genes with 59 somatic variants were identified by WES. In targeted resequencing, variants in 26 recurrent genes, including MAST4, PRIM2, TNN, STARD9, DNAH11, DOCK4, GPR98, BCHE, DARS, CUBN, NGDN, PLXND1, UNC5B, and COL22A1, were identified, but variants in previously reported genes were not detected. BCHE, DARS, NGDN, and UNC5B variants were associated with increased GH-secreting pituitary tumor biochemical activity, which was confirmed in vitro. Although recurrent point variants were rare, several somatic variants were identified in sporadic pure GH-secreting pituitary adenomas. Several somatic variants may affect pathways involved in the tumorigenesis and biochemical activities of GH-secreting pituitary adenomas.

Long-term effects of somatostatin analogues in rat GH-secreting pituitary tumor cell lines

PurposeFirst-generation somatostatin analogs, octreotide (OCT) and lanreotide, are the cornerstone for the medical treatment of growth hormone (GH)-secreting pituitary tumors. A new multireceptor analog, such as pasireotide (PAS), showed better activity than OCT in long-term treatment of patients with acromegaly, but modulation of intracellular key processes is still unclear in vitro. In this study, we evaluated the antitumor activity of OCT and PAS in two GH-secreting pituitary tumor cell lines, GH3 and GH4C1, after a long-term incubation.MethodsThe effects of PAS and OCT on the cell viability, cell cycle, apoptosis, GH secretion, and tumor-induced angiogenesis have been evaluated through a colorimetric method (MTS Assay), DNA flow cytometry with propidium iodide, and Annexin V-FITC/propidium iodide staining, ELISA assay and zebrafish platform, respectively.ResultsPAS showed a more potent antitumor activity compared to OCT in GH3 cell line exerted through inhibition of cell viability, perturbation of cell cycle progression, and induction of apoptosis after 6 days of incubation. A concomitant decrease in GH secretion has been observed after 2 days of incubation only with PAS. No effect on tumor-induced angiogenesis has been reported after treatment with OCT or PAS in zebrafish/tumor xenograft model.ConclusionLong-term incubation with PAS showed a more potent antitumor activity than that reported after OCT in GH3 cells, mainly modulated by a cell cycle perturbation and a relevant induction in apoptosis.