Non-islet cell tumor hypoglycemia as a result of insulin-like growth factor (IGF)-2 secretion is rare. A 59-year-old woman was referred with postmenopausal bleeding due to endometrial hyperplasia. Serum testosterone, estradiol, and adrenal androgens were elevated with suppressed gonadotropin concentrations. Cross-sectional imaging demonstrated a large left adrenal mass. The patient subsequently presented acutely with hypoglycemia. During a supervised fast, symptomatic hypoglycemia occurred within 5 hours. Serum samples drawn prior to hypoglycemia correction revealed an elevated IGF-2:IGF-1 ratio of 60.7 (normal <10) with low paired C-peptide and insulin, consistent with an IGF-2-secreting tumor. Hypoglycemia was managed with low-glycemic index foods and radical surgical excision was undertaken. Postoperative pathology revealed an adrenocortical carcinoma (ACC); Ki67 12%; IGF-2 positive immunostaining. This case demonstrates a rare IGF-2-secreting ACC causing clinically significant hypoglycemia with positive immunostaining for IGF-2 in addition to biochemical hyperandrogenism resulting in endometrial hyperplasia and postmenopausal bleeding. This case encompasses 2 unique syndromes from the cosecretion of both peptide factor and steroid hormone.

Non-islet cell tumor hypoglycemia (NICTH) is a rare cause of hypoglycemia, resulting from excessive secretion of insulin-like growth factor 2 (IGF-2) or pro-IGF‑2, which leads to subsequent activation of the insulin receptor. Doege-Potter syndrome is often used synonymously with NICTH, especially in cases with fibrous primary tumors in the thorax. In the current patient, tumor progression was observed over a short period without the possibility of debulking surgery. Therefore, oral therapy with prednisolone was initiated. Treatment with diazoxide or the somatostatin analogue octreotide is not recommended for NICTH.

Spontaneous and refractory hypoglycemia in malignancy poses diagnostic challenges, since its exact underlying mechanisms remain unclear. A 62-year-old female patient with a 10-year type 2 diabetes mellitus history presented with abdominal pain and spontaneous hypoglycemia despite discontinuation of her diabetic treatments. An initial computed tomography (CT) scan revealed a large perinephric tumor, and a second CT, performed a week later, demonstrated significant tumor growth. On admission, she had no neuroglycopenic symptoms despite a serum glucose level of 25 mg/dL (1.39 mmol/L). She showed suppressed insulin and insulin-like growth factor (IGF)-1 levels, elevated lactate levels, a pH of 7.434 with an anion gap of 24.1, and a negative test for anti-insulin antibody. A percutaneous CT-guided tumor biopsy revealed diffuse large B-cell lymphoma. She received continuous dextrose supplementation and prednisolone to alleviate the severe hypoglycemia, but she died from the tumor burden on the sixth day of hospitalization. Postmortem serum immunoblotting revealed the absence of partially processed IGF-2 precursors. The patient's refractory hypoglycemia and hyperlactatemia were consistent with tumor-associated aerobic glycolytic lactate production, known as the Warburg effect. This case illustrates the importance of increased awareness of this underrecognized oncologic emergency in the differential diagnosis of profound spontaneous hypoglycemia in malignancy.

hypoglycemia is a common and multifactorial clinical condition. A rare cause is that associated with non-islet cell tumors.

to report our experience on the management of severe hypoglycemia in a patient with solitary pleural fibrous tumor and his response to pasireotide.

63-year-old patient with a history of glomerulonephritis, hypothyroidism, arterial hypertension and a one-year diagnosis of solitary pleural fibrous tumor. Referred to endocrinology due to hypoglycemia for 6 months. Acromegaloid features were confirmed. Laboratory: Hct 36%, Hb 11.9 g/dl, GB 3570/mm3 (Eo 2%, Ba2%, Bac 4%, NS 36%, Li 30%, Mo 14% metamyelocytes 1%, myelocytes 11%), platelets 120,000 /mm3, ESR 10 mm, CRP 9 mg/L, TP 114%, TTPK 25 sec, blood glucose 57 mg/dL, renal function, hepatogram and lipid profile without particularities. IGF-1 84 ng/ml (VR 57 - 188), C-peptide 0.10 ng/ml (VR 1.10 - 4.40), somatotropin 0.98 ng/ml (VR up to 2.5) and basal insulin 0.4 uU/ml (VR 2.6 - 24) . IFG-2 measurement is not available in Argentina. A chest CT showed a pleural tumor measuring 13 cm. Without possibilities of surgical resection and without response to chemotherapy. Treatment was started with infusion of 25% dextrose, dexamethasone, pasireotide with good response. The patient died due to an infectious complication.

pasireotide could be a therapeutic alternative in cases that are not candidates for surgery or refractory to other medical treatment.

Growth hormone (GH) is a pituitary-derived endocrine hormone required for normal postnatal growth and development. Hypo- or hypersecretion of endocrine GH results in 2 pathologic conditions, namely GH deficiency (GHD) and acromegaly. Additionally, GH is also produced in nonpituitary and tumoral tissues, where it acts rather as a cellular growth factor with an autocrine/paracrine mode of action. An increasingly persuasive and large body of evidence over the last 70 years concurs that GH action is implicit in escalating several cancer-associated events, locally and systemically. This pleiotropy of GH's effects is puzzling, but the association with cancer risk automatically raises a concern for patients with acromegaly and for individuals treated with GH. By careful assessment of the available knowledge on the fundamental concepts of cancer, suggestions from epidemiological and clinical studies, and the evidence from specific reports, in this review we aimed to help clarify the distinction of endocrine vs autocrine/paracrine GH in promoting cancer and to reconcile the discrepancies between experimental and clinical data. Along this discourse, we critically weigh the targetability of GH action in cancer-first by detailing the molecular mechanisms which posit GH as a critical node in tumor circuitry; and second, by enumerating the currently available therapeutic options targeting GH action. On the basis of our discussion, we infer that a targeted intervention on GH action in the appropriate patient population can benefit a sizable subset of current cancer prognoses.

Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome caused by the secretion of high molecular weight insulin-like growth factor II (IGF-II) from tumors, particularly those of mesenchymal and epithelial origin. This case report describes a 71-year-old male with pelvic sarcoma who presented with severe hypoglycemia, with blood glucose levels dropping below 40 mg/dL and exhibiting neuroglycopenic symptoms. The diagnosis of NICTH was confirmed through biochemical analysis showing hypoinsulinemic hypoglycemia alongside low C-peptide and IGF-1 levels. Initial management with dextrose infusions and glucocorticoids proved ineffective until recombinant human growth hormone (rhGH) therapy was initiated, resulting in a decreased requirement for dextrose. Following angioembolization of the tumor, the patient's blood glucose levels stabilized sufficiently to allow for the complete cessation of dextrose administration. This case highlights the critical role of rhGH in reducing dextrose dependency and the effectiveness of angioembolization in managing NICTH when surgical options are limited.

The heterogeneity of hepatocellular carcinoma (HCC) is linked to tumor malignancy and poor prognosis. Nevertheless, the precise mechanisms underlying the development of the cholangiocellular phenotype (CCA) within HCC remain unclear. Emerging studies support that the cross-talk among the host cells within tumor microenvironment (TME) sustains the cancer cell plasticity.

This study sought to identify the specific cell types involved in the formation of CCA and to elucidate their functional roles in the progression of HCC.

Single-cell RNA sequencing was employed to identify the specific cell types involved in the formation of CCA. Both in vitro and vivo analyses were used to identify the tumor-associated senescent ECs and investigate the function in TME. The diethylnitrosamine-induced model was utilized to investigate the interaction between senescent ECs and MSCs, aiming to elucidate their synergistic contributions to the progression of CCA.

Using single-cell RNA sequencing, we identified a distinct senescent-associated subset of endothelial cells (ECs), namely CD34+CLDN5+ ECs, which mainly enriched in tumor tissue. Further, the senescent ECs were observed to secrete IGF2, which recruited mesenchymal stem cells (MSCs) into the TME through IGF2R/MAPK signaling. In primary liver cancer model, MSCs exhibited a strong tumor-promoting effect, increasing the CCA and tumor malignancy after HCC formation. Interestingly, knockdown of IGF2R expression in MSCs inhibited the increase of CCA caused by MSCs in HCC. Meanwhile, it was revealed that MSCs released multiple inflammatory and trophic-related cytokines to enhance the cancer stem cell-like characteristics in HCC cells. Finally, we demonstrated that CEBPβ up-regulated IGF2 expression in tumor senescent ECs by combining with Igf2-promtor-sequence.

Together, our findings illustrated that tumor associated senescent ECs in HCC recruited the MSCs into TME, enhancing cancer stem cell (CSC)-like features of HCC cells and contributing to the CCA formation.

The development of tyrosine-kinase inhibitors has improved survival rates for patients with gastrointestinal stromal tumors (GISTs). Despite the progress, not all the patients can universally receive the benefit from treatment due to the individual underlying conditions in a real-world setting. The present study focused on the well-known but understudied condition of GIST with hypoglycemia. Hypoglycemia in GIST is characterized by hypoglycemic symptoms such as dizziness, sweating and confusion. It is caused by several factors such as multiple liver metastases, drug adverse effects, postoperative complications and paraneoplastic syndrome [non-islet cell tumor hypoglycemia (NICTH)]. Comprehensive analysis of this condition has been hindered due to its rarity, and has been mostly limited to case reports. In the present study, a single-institution retrospective analysis of GIST with hypoglycemia was conducted to investigate its prevalence and prognosis, and the cause of this condition. The present study identified that the prevalence of hypoglycemic episodes of GIST was 4.1% in all patients with GIST, and recurrent hypoglycemic cases had a poor prognosis. The present study identified 1 case with recurrent hypoglycemia due to NICTH. Since NICTH is a rare hypoglycemic cause and requires further evaluation, an autopsy and genetic sequencing were performed using the available clinical materials. Through this histological and genetic investigation, the histological diversity of NICTH-GIST was revealed and insulin-like growth factor II (IGF-II) amplification was identified. Furthermore, a chronological analysis was performed using multiple resected archived samples from the same case, and revealed that diffuse IGF-II expression may have occurred in the early phase of tumor development. The present study catalogued the characteristics of GIST with hypoglycemia with a focus on NICTH-GIST.

Recurrent hypoglycaemia is a rare paraneoplastic syndrome associated with several cancers, including renal cell carcinoma (RCC). Here we present a curious case of a patient with type 2 diabetes mellitus (T2DM) who had numerous hospitalisations due to recurrent hypoglycaemia. A well-defined lesion at the lower pole of the right kidney and bilateral pyelonephritis were found during imaging investigations. A biopsy from the lesion confirmed clear cell carcinoma of the kidney and the most probable cause of recurrent hypoglycemia was paraneoplastic syndrome related to RCC. Analysis of Insulin-like growth factor levels revealed that recurrent hypoglycaemia might be the result of non-islet cell tumor-hypoglycaemia (NICTH). This case emphasizes how crucial it is to rule out paraneoplastic syndromes like NICTH in individuals presenting with hypoglycaemia that cannot be explained, even when pre-existing diabetes is present. Furthermore, this study emphasizes the need to include RCC in the differential diagnosis.

Non-islet cell tumor hypoglycemia (NICTH) is an uncommon condition, of which only a few cases caused by malignant phyllodes tumor of the breast have been reported. We describe a case of NICTH secondary to malignant phyllodes tumor with good response to glucocorticoid therapy.

A 62-year-old woman with a rapidly enlarging left breast mass presented with drowsiness and a capillary blood glucose level of 32.4 mg/dL. Her plasma glucose and insulin levels were 36.0 mg/dL (reference range, 72-144 mg/dL) and 0.6 mIU/L (reference range, 0.0-25.0 mIU/L), respectively. Her beta-hydroxybutyrate and c-peptide levels were undetectable. The insulin-like growth factor (IGF)-I and IGF-II levels were 37 μg/L (reference range, 43-220 μg/L) and 1062 ng/mL (reference range, 333-967 ng/mL), respectively, with an IGF-II:IGF-I molar ratio of 29.4. Prednisolone 30 mg per day was initiated with improvement in hypoglycemia. Outpatient flash glucose monitoring profile was stable with mild hypoglycemia (glucose level, 54-68.5 mg/dL) detected 5% of the time. The patient underwent left mastectomy with axillary clearance 4 weeks later. Histology was reported as malignant phyllodes tumor with extensive ductal carcinoma in situ. Prednisolone was stopped after surgery. The patient was treated with letrozole and adjuvant radiotherapy. There was no recurrence of hypoglycemia during the subsequent 24-month follow-up.

The mainstay of treatment for NICTH is surgical resection of the culprit tumor. Although glucocorticoid treatment has also been widely used for NICTH, few reports have demonstrated efficacy for NICTH secondary to phyllodes tumor.

We report a rare case of malignant phyllodes tumor of the breast resulting in NICTH and demonstrated good response to glucocorticoids as a bridge to definitive surgery.

Malignant peritoneal mesothelioma (MPM) is a rare and invasive tumor, and some patients will develop paraneoplastic syndrome (PS) during the course of the disease. This review summarizes PS associated with MPM, focusing on the clinical characteristics and treatment progress in hematological, endocrine, rheumatic, neurological, urinary, and other systems to decrease missed diagnosis and misdiagnosis, help early diagnosis and prompt treatment, and provide guidance for the clinical decision-making of this kind of patients.

Paraneoplastic hypoglycemia, also known as non-islet cell tumor hypoglycemia (NICTH), is a rare but critical condition occurring in patients with different types of malignancy. This condition is commonly linked to tumors producing insulin-like growth (IGF) factors, particularly IGF-2 and its precursors, which disrupt glucose homeostasis and lead to excessive glucose consumption. The diagnosis typically involves documenting symptomatic hypoglycemia and ruling out other potential causes. Essential diagnostic tools include imaging studies and laboratory tests, specifically measuring IGF-2 levels and the IGF-2:IGF-1 ratio. Treatment strategies for NICTH are multifaceted and may include surgical resection of the tumor if feasible, pharmacological interventions such as corticosteroids to suppress IGF-2 production, or supportive measures to manage acute hypoglycemic episodes. Novel therapeutic approaches targeting IGF-2, such as monoclonal antibodies or siRNA, are also being explored and hold promise for future treatment options. This review aims to enhance understanding of paraneoplastic hypoglycemia, focusing on its pathogenesis and diagnosis, to guide optimal medical treatment.

Doege-Potter syndrome, characterized by solitary fibrous tumors and non-islet cell tumor hypoglycemia, is rare. Here, we report a case of Doege-Potter syndrome in which retroperitoneal tumor resection was performed with continuous intraoperative blood glucose monitoring.

A 37-year-old man presented with hypoglycemia-related symptoms, and a 10 × 12 × 9 cm tumor was found in his right kidney. Following tumor resection, insulin secretory abnormalities improved, and intraoperative blood glucose monitoring showed no hypoglycemic events. High levels of insulin-like growth factor-II confirmed the diagnosis of an insulin-like growth factor-II-producing tumor with non-islet cell tumor hypoglycemia. Postoperative serum insulin-like growth factor-II levels normalized, with no recurrence observed over 3 years.

This case highlights the rarity of primary retroperitoneal Doege-Potter syndrome, emphasizes the safety of intraoperative blood glucose levels during surgery, and suggests rapid recovery of insulin secretion postoperatively.

The acid-labile subunit (ALS) of the insulin-like growth factor (IGF) binding protein (IGFBP) complex, encoded in humans by IGFALS, has a vital role in regulating the endocrine transport and bioavailability of IGF-1 and IGF-2. Accordingly, ALS has a considerable influence on postnatal growth and metabolism. ALS is a leucine-rich glycoprotein that forms high-affinity ternary complexes with IGFBP-3 or IGFBP-5 when they are occupied by either IGF-1 or IGF-2. These complexes constitute a stable reservoir of circulating IGFs, blocking the potentially hypoglycaemic activity of unbound IGFs. ALS is primarily synthesized by hepatocytes and its expression is lower in non-hepatic tissues. ALS synthesis is strongly induced by growth hormone and suppressed by IL-1β, thus potentially serving as a marker of growth hormone secretion and/or activity and of inflammation. IGFALS mutations in humans and Igfals deletion in mice cause modest growth retardation and pubertal delay, accompanied by decreased osteogenesis and enhanced adipogenesis. In hepatocellular carcinoma, IGFALS is described as a tumour suppressor; however, its contribution to other cancers is not well delineated. This Review addresses the endocrine physiology and pathology of ALS, discusses the latest cell and proteomic studies that suggest emerging cellular roles for ALS and outlines its involvement in other disease states.

Non-islet cell tumor hypoglycemia (NICTH) is a rare clinical entity associated with large mesenchymal tumors. Its pathogenesis is most commonly mediated by tumor overproduction of "big" insulin-like growth factor-2. Here, we present a 54-year-old male who presented with noninsulin-mediated hypoglycemia and a 20 cm intra-abdominal leiomyoma. His hypoglycemic episodes resolved after the resection of his tumor. To our knowledge, this is the only documented case in the English literature of NICTH associated with leiomyoma in a male patient. NICTH due to a benign leiomyoma should be in the differential diagnosis for any patient with hypoglycemia and an abdominal mass.

Solitary fibrous tumors (SFT) are mesenchymal cell tumors that may arise from any site throughout the body. A small percentage of patients with SFT develop non-islet cell tumor-induced hypoglycemia (NICTH), eponymously termed Doege-Potter Syndrome (DPS). DPS is characterized by severe, refractory hypoinsulinemic hypoglycemia. Diagnosis of SFT is dependent on histologic findings and immunohistochemistry (IHC). NAB2-STAT6 gene fusions are pathognomonic for SFT but may be difficult to identify in routine cytogenetic studies. STAT6 IHC is a highly sensitive and specific surrogate for the NAB2-STAT6 gene fusion. Total resection of the tumor remains the gold-standard definitive treatment of SFT of the pleura. Palliative tumor debulking is recommended if total resection is not feasible. We here report a case of DPS in a 73-year-old female, managed with palliative care.

This case report delineates the clinical presentation of a 77-year-old male who experienced falls and sustained a humerus fracture attributed to hypoglycemia. Despite the absence of insulin use and normal laboratory results for cortisol, TSH, blood count, and liver and kidney function, a fasting test revealed diminished C-peptide and insulin levels, ruling out insulinoma, exogenous insulin use, or β-cell hyperplasia. Subsequent laboratory investigations demonstrated lowered IGF-1 and elevated IGF-2 levels, indicative of an IGF-2-producing tumor as the etiology of the hypoglycemia. A positron emission tomography computed tomography scan identified a right-sided thoracic cavity tumor, prompting an open resection. Postoperatively, hypoglycemic episodes abated within 2 days, and pathology confirmed a 14.9-cm solitary fibrous tumor. Nonislet cell tumor hypoglycemia (NICTH), also known as Doege Potter syndrome, arises from aberrant production of IGF-2 or its precursors. Elevated IGF-2 levels induce hypoglycemia through heightened glucose uptake on binding to insulin receptors. The literature supports the efficacy of both surgical intervention and corticosteroids in managing NICTH. This case underscores the importance of considering NICTH as a rare etiology in unexplained hypoglycemia cases, advocating for the utility of fasting tests in diagnosis, and suggesting surgical resection as a viable treatment option when radical excision is feasible.

The occurrence of hypoglycemia in patients without diabetes is rare, and non-islet cell tumor hypoglycemia (NICTH) accounts for a small portion of these instances. One of the infrequent causes is associated with tumor cell production of Insulin-like growth factor (IGF)-2. Here is a case of a 66-year-old man with stage IV colon cancer who presented to the emergency department with breathlessness during chemotherapy (Bevacizumab plus FOLFOX4 regimen). He had undergone partial colectomy and chemotherapy three years prior but was recently diagnosed with metastatic liver disease. A CT scan revealed a 15 cm hepatic mass occupying the entire right hepatic lobe. Despite receiving dextrose infusions, he experienced persistent hypoglycemia after meals and during fasting. Given that he had no history of diabetes and denied using any oral hypoglycemic agents, the Endocrinology service was consulted for further evaluation. Plasma blood glucose (BG) was measured at 74 mg/dL (reference range 74-106) during dextrose administration. An 8 AM cortisol test yielded a result of 8.08 mcg/dL (4.30-22.40), ruling out adrenal insufficiency. A 72-hour fast was initiated but terminated at eight hours due to symptomatic hypoglycemia with a plasma BG of 48 mg/dL. C-peptide and Insulin levels were both low, measuring <0.05 ng/mL (0.48-5.05) and <1.0 mU/L (3.0-25), respectively, while beta-hydroxybutyrate (BHB) levels were normal at 1.1 mg/dL (0.2-2.8). Administration of 1 mg glucagon during the fast increased BG to 112 mg/dL within 2 hours. IGF-1 levels were undetectable (<1.9 nmol/L), while IGF-2 levels were at 23 nmol/L (44-129 nmol/L), resulting in an IGF2:IGF1 ratio of 12 (>10), confirming IGF-2 mediated NICTH. Treatment with dexamethasone 10 mg daily was initiated, maintaining blood glucose levels above 70 mg/dL without dextrose infusion. In approximately 50% of cases of NICTH, the tumor is detected before the onset of hypoglycemia, yet up to half the patients may remain asymptomatic despite having very low BG. Despite having a known hepatic lesion, our patient exhibited minimal symptoms despite severely low BG levels. The mechanisms underlying NICTH may involve tumor secretion of insulin, replacement of hepatic tissue, increased glucose utilization by the tumor, or, most commonly, secretion of IGF-2. In cases of IGF-2-mediated hypoglycemia, insulin, proinsulin, C-peptide, and β-hydroxybutyrate levels are typically low. IGF-2 stimulates the insulin receptors resulting in increased glucose uptake by skeletal muscles and suppression of gluconeogenesis, glycogenolysis, and ketogenesis by the liver. Insulin secretion from pancreatic β-cells is suppressed. IGF-1 levels are usually low, while IGF-2 levels may be high or normal, as many IGF-2omas produce IGF-2 precursors (pro-IGF-2). An elevated IGF-2:IGF-1 ratio (>10) confirms the diagnosis which may be helpful when IGF-2 levels are normal. The primary treatment is through surgical removal or debulking of the tumor. Neoadjuvant therapies such as radiation and chemotherapy may reduce occurrences of hypoglycemia, but only temporarily. Glucocorticoids may be used when the underlying malignancy cannot be treated.

Non-islet cell tumor hypoglycemia (NICTH) is a paraneoplastic syndrome caused by tumors other than insulinoma that is primarily due to excessive production of insulin-like growth factor-II (IGF-II). The prevalence of NICTH is likely underestimated because of a lack of clinical recognition.

A 41-year-old male with massive malignant liver tumors presented with recurrent severe hypoglycemia, weight loss, and liver cirrhosis.

NICTH related to IGF-II produced by hepatocellular carcinoma was diagnosed based on clinical symptoms, biochemical tests, and elevated IGF-II/IGF-I ratio.

Initial treatment with intravenous glucose and parenteral nutrition showed limited efficacy. Glucocorticoids and recombinant human growth hormone led to progressive improvement in blood glucose levels.

Due to extensive tumor burden and liver failure, surgical resection was not feasible, and the patient ultimately succumbed to refractory hypoglycemia and passed away in two weeks.

Early recognition and diagnosis of NICTH are crucial in patients with recurrent hypoglycemia and large tumors. Surgical resection is the preferred treatment option, but supportive care and pharmacological interventions, such as glucocorticoids and growth hormone, can help manage refractory hypoglycemia. Further research is needed to explore novel treatment options, including anti-IGF-I and -IGF-II neutralizing antibodies.

Insulin receptor (IR) controls growth and metabolism. Insulin-like growth factor 2 (IGF2) has different binding properties on two IR isoforms, mimicking insulin's function. However, the molecular mechanism underlying IGF2-induced IR activation remains unclear. Here, we present cryo-EM structures of full-length human long isoform IR (IR-B) in both the inactive and IGF2-bound active states, and short isoform IR (IR-A) in the IGF2-bound active state. Under saturated IGF2 concentrations, both the IR-A and IR-B adopt predominantly asymmetric conformations with two or three IGF2s bound at site-1 and site-2, which differs from that insulin saturated IR forms an exclusively T-shaped symmetric conformation. IGF2 exhibits a relatively weak binding to IR site-2 compared to insulin, making it less potent in promoting full IR activation. Cell-based experiments validated the functional importance of IGF2 binding to two distinct binding sites in optimal IR signaling and trafficking. In the inactive state, the C-terminus of α-CT of IR-B contacts FnIII-2 domain of the same protomer, hindering its threading into the C-loop of IGF2, thus reducing the association rate of IGF2 with IR-B. Collectively, our studies demonstrate the activation mechanism of IR by IGF2 and reveal the molecular basis underlying the different affinity of IGF2 to IR-A and IR-B.

A patient without a diagnosis of diabetes mellitus presented to the hospital due to a fall and hypoglycaemia on admission. The patient was found to have recurrent nocturnal fasting hypoglycaemia. CT revealed a large lung mass consistent with a solitary pleural fibroma, a rare tumour associated with insulin-like growth factor 2 (IGF-2) production. This case is an important reminder that potential causes of hypoglycaemia should be considered in non-diabetic patients.

Insulin-like growth factor-2 (IGF-2)-mediated hypoglycemia is a rare yet clinically significant entity with considerable morbidity and mortality. Existing literature is limited and fails to offer a comprehensive understanding of its clinical trajectory, management and prognostication.

Systematic review of English-language articles reporting primary patient data on IMH was searched using electronic databases (PubMed, Scopus and Embase) from any date up to 21 December 2022. Data were analysed in STATA-16.

The systematic review contains 172 studies, including 1 Randomised controlled trial, 1 prospective observational study, 5 retrospective observational studies, 150 case reports, 11 case series and 4 conference abstracts. A total of 233 patients were analysed, averaging 60.6 ± 17.1 years in age, with comparable proportions of males and females. The commonest tumours associated with Insulin-like Growth Factor-2-mediated hypoglycaemia were fibrous tumours (N = 124, 53.2%), followed by non-fibrous tumours originating from the liver (N = 21, 9%), hemangiopericytomas (N = 20, 8.5%) and mesotheliomas (N = 11, 4.7%). Hypoglycaemia was the presenting feature of NICT in 42% of cases. Predominant clinical features included loss of consciousness (26.7%) and confusion (21%). The mean IGF-2 and IGF-1 levels were 882.3 ± 630.6 ng/dL and 41.8 ± 47.8, respectively, with no significant correlation between these levels and patient outcomes. Surgical removal was the most employed treatment modality (47.2%), followed by medication therapy. The recovery rate was 77%, with chronic liver disease (CLD) significantly associated with a poor outcome (OR: 7.23, P: 0.03). Tumours originating from fibrous tissues were significantly associated with recovery (p < .001). In the logistic regression model, CLD remained a significant predictor of poor outcomes.

This systematic review highlights that most non-islet-cell tumour-hypoglycaemia (NICTH) is due to fibrous tumours. NICTs demonstrate a variable prognosis, which is fair if originating from fibrous tissue. Management such as octreotide, corticosteroids, diazoxide, embolization, radiotherapy and surgical resection have disparate success rates.

Doege-Potter syndrome occurs when incompletely processed insulin-like growth factor 2 (IGF-2), also known as big IGF-2, is produced by a solitary fibrous tumor (SFT) and results in non-islet cell tumor hypoglycemia (NICTH). We discuss here the case of a 66-year-old male who presented with a 2-week history of increasing confusion and a serum glucose of 34 mg/dL. The patient's symptoms immediately improved with dextrose. The patient did not use insulin, serum sulfonylurea screen was negative, and testing for adrenal insufficiency was unremarkable. Outpatient laboratory evaluation revealed a serum glucose of 48 mg/dL along with low insulin, C-peptide, and proinsulin levels. Further work-up showed an IGF-2 to IGF-1 ratio of 38:1. A ratio greater than 10:1 is diagnostic of NICTH. Imaging demonstrated a 21-cm mass in the lower abdomen and pelvis. The patient underwent surgical resection. The hypoglycemia resolved immediately postoperatively. Surgical pathology revealed a malignant SFT. In NICTH, big IGF-2 forms a complex that is biologically active and saturates the insulin and IGF receptors, resulting in refractory hypoglycemia. Although glucocorticoids can mitigate hypoglycemia, complete surgical resection is the only definitive treatment of NICTH. This case highlights the importance of maintaining a broad differential for seemingly simple hypoglycemia.

The paraneoplastic syndrome referred in the literature as non-islet-cell tumor hypoglycemia (NICTH) and extra-pancreatic tumor hypoglycemia (EPTH) was first reported almost a century ago, and the role of cancer-secreted IGF-II in causing this blood glucose-lowering condition has been widely established. The landscape emerging in the last few decades, based on molecular and cellular findings, supports a broader role for IGF-II in cancer biology beyond its involvement in the paraneoplastic syndrome. In particular, a few key findings are constantly observed during tumorigenesis, (a) a relative and absolute increase in fetal insulin receptor isoform (IRA) content, with (b) an increase in IGF-II high-molecular weight cancer-variants (big-IGF-II), and (c) a stage-progressive increase in the IGF-II autocrine signal in the cancer cell, mostly during the transition from benign to malignant growth. An increasing and still under-exploited combinatorial pattern of the IGF-II signal in cancer is shaping up in the literature with respect to its transducing receptorial system and effector intracellular network. Interestingly, while surgical and clinical reports have traditionally restricted IGF-II secretion to a small number of solid malignancies displaying paraneoplastic hypoglycemia, a retrospective literature analysis, along with publicly available expression data from patient-derived cancer cell lines conveyed in the present perspective, clearly suggests that IGF-II expression in cancer is a much more common event, especially in overt malignancy. These findings strengthen the view that (1) IGF-II expression/secretion in solid tumor-derived cancer cell lines and tissues is a broader and more common event compared to the reported IGF-II association to paraneoplastic hypoglycemia, and (2) IGF-II associates to the commonly observed autocrine loops in cancer cells while IGF-I cancer-promoting effects may be linked to its paracrine effects in the tumor microenvironment. Based on these evidence-centered considerations, making the autocrine IGF-II loop a hallmark for malignant cancer growth, we here propose the functional name of IGF-II secreting tumors (IGF-IIsT) to overcome the view that IGF-II secretion and pro-tumorigenic actions affect only a clinical sub-group of rare tumors with associated hypoglycemic symptoms. The proposed scenario provides an updated logical frame towards biologically sound therapeutic strategies and personalized therapeutic interventions for currently unaccounted IGF-II-producing cancers.

Non-islet cell tumour hypoglycaemia (NICTH) is a rare cause of hypoglycaemia. There is no single pathogenic mechanism that can explain all cases of NITCH. With this case, we wish to highlight the complexity in diagnosis and management of this condition.

Insulin-like Growth Factor-2 (IGF2) is important for the regulation of human embryonic growth and development, and for adults' physiology. Incorrect processing of the IGF2 precursor, pro-IGF2(156), leads to the formation of two IGF2 proforms, big-IGF2(87) and big-IGF2(104). Unprocessed and mainly non-glycosylated IGF2 proforms are found at abnormally high levels in certain diseases, but their mode of action is still unclear. Here, we found that pro-IGF2(156) has the lowest ability to form its inactivating complexes with IGF-Binding Proteins and has higher proliferative properties in cells than IGF2 and other IGF prohormones. We also showed that big-IGF2(104) has a seven-fold higher binding affinity for the IGF2 receptor than IGF2, and that pro-IGF2(87) binds and activates specific receptors and stimulates cell growth similarly to the mature IGF2. The properties of these pro-IGF2 forms, especially of pro-IGF2(156) and big-IGF2(104), indicate them as hormones that may be associated with human diseases related to the accumulation of IGF-2 proforms in the circulation.

Hypoglycemia is due to defects in the metabolic systems involved in the transition from the fed to the fasting state or in the hormone control of these systems. In children, hypoglycemia is considered a metabolic-endocrine emergency, because it may lead to brain injury, permanent neurological sequelae and, in rare cases, death. Symptoms are nonspecific, particularly in infants and young children. Diagnosis is based on laboratory investigations during a hypoglycemic event, but it may also require biochemical tests between episodes, dynamic endocrine tests and molecular genetics. This narrative review presents the age-related definitions of hypoglycemia, its pathophysiology and main causes, and discusses the current diagnostic and modern therapeutic approaches.

Non-islet cell tumor-induced hypoglycemia (NICTH) is a rare, life-threatening medical condition caused by excessive insulin-like growth factor II (IGF-II) secretion from tumors of most commonly mesenchymal origin. Using next-generation sequencing, we have characterized the genome and transcriptome of the resected IGF-II-secreting solitary fibrous tumor from a patient with severe hypoglycemia accompanied by hypoglycemia unawareness.

A 69-year-old male patient presenting with abdominal discomfort was examined using computer tomography, revealing a large lesion at the lesser pelvis extending above the umbilicus. As no bone and lymph node metastases were detected, the patient was scheduled for laparotomy. Before surgery, the patient presented with symptoms of severe hypoglycemia. Suppressed C-peptide levels and subsequent hypokalemia indicated a possible case of NICTH. The patient was treated with methylprednisolone (8 mg) to assess hypoglycemia. After the surgery, mild hypoglycemia was present for the postoperative period, and no radiological recurrences were observed 3 and 12 months after discharge. Histopathological examination results were consistent with the diagnosis of malignant solitary fibrous tumor (SFT). Overexpression of IGF-II was confirmed by both immunohistochemistry and RNA sequencing. Further NGS analysis revealed an SFT characteristic alteration-NAB2-STAT6 fusion. Additionally, three deleterious missense variants were detected in oncogenes BIRC6, KIT, and POLQ, and one homozygous in-frame deletion in the RBM10 tumor suppressor gene.

While the NAB2-STAT6 fusions are well characterized, the mutational landscape of SFTs remains understudied. This study reports the importance of NGS to characterize SFTs as we detected four coding variants in genes (BIRC6, KIT, POLQ, and RBM10) associated with tumorigenesis that could potentially contribute to the overall pathogenesis of SFT.

Non-islet cell tumor hypoglycemia (NICTH) is a rarely encountered cause of hypoglycemia. It is most often caused by tumor secretion of precursor insulin-like growth factor-2 (IGF-2) which, in high concentrations, binds to insulin receptors exerting insulin-like metabolic effects. It is often associated with mesenchymal and hepatic tumors. We describe 3 cases of NICTH: a 60-year-old man with an unresectable pelvic sarcoma and two women ages 43 and 57 with metastatic hemangiopericytoma. Biochemical assessment identified hypoglycemia associated with suppressed insulin, c-peptide, and beta-hydroxybutyrate levels. Each patient was treated with oral glucocorticoids, which effectively prevented recurrence of hypoglycemia and this effect was sustained long-term. These cases highlight a rarely encountered but important cause of hypoglycemia and demonstrate the long-term efficacy of glucocorticoid treatment in preventing hypoglycemia in cases of NICTH related to surgically unresectable tumors.

Until recently, Deltex (DTX) proteins have been considered putative E3 ligases, based on the presence of an E3 RING domain in their protein coding sequence. The human DTX family includes DTX1, DTX2, DTX3, DTX3L and DTX4. Despite the fact that our knowledge of this class of E3-ubiquitin ligases is still at an early stage, our understanding of their role in oncogenesis is beginning to unfold. In fact, recently published studies allow us to define specific biological scenarios and further consolidate evidence-based working hypotheses. According to the current evidence, all DTX family members are involved in the regulation of Notch signaling, suggesting a phylogenetically conserved role in the regulation of this pathway. Indeed, additional evidence reveals a wider involvement of these proteins in other signaling complexes and cancer-promoting mechanisms beyond NOTCH signaling. DTX3, in particular, had been known to express two isoform variants (DTX3a and DTX3b). The recent identification and cloning of a third isoform variant in cancer (DTX3c), and its specific involvement in EphB4 degradation in cancer cells, sheds further light on this group of proteins and their specific role in cancer. Herein, we review the cumulative knowledge of this family of E3 Ubiquitin ligases with a specific focus on the potential oncogenic role of DTX isoforms in light of the rapidly expanding findings regarding this protein family's cellular targets and regulated signaling pathways. Furthermore, using a comparative and bioinformatic approach, we here disclose a new putative motif of a member of this family which may help in understanding the biological and contextual differences between the members of these proteins.

Hypoglycemia in patients without diabetes is a diagnostic challenge for the endocrinologist. Sometimes it is related to rare causes such as Doege-Potter Syndrome (DPS). DPS is caused by an abnormal insulin-like grow factor 2(IGF-2) that retains part of the E domain during the production process, resulting in a longer peptide called "big-IGF-2". We present a case report of DPS with emphasis on the diagnosis and especially on the difficulties in interpreting the biochemical findings. An elderly patient with an intrathoracic neoplasm and hypoglycemia underwent various tests: insulin autoantibodies and fasting test were both negative. She had low values of IGF-1 and normal values of IGF-2 that apparently excludes a diagnosis of DPS. The evaluation of the IGF-2/IGF-1 ratio is the most important test because a ratio >10 is widely considered to be indicative of non-islet cell tumor hypoglycemia (NICTH). Glucose infusion and steroid therapy were used to control the hypoglycemia, but the definitive treatment was surgery, which almost immediately reversed the hypoglycemia. The differential diagnosis of hypoglycemia should include rare causes such as DPS, and the IGF-2/IGF-1 ratio is a useful tool.

Regulation of the human IGF2 gene displays multiple layers of control, which secures a genetically and epigenetically predetermined gene expression pattern throughout embryonal growth and postnatal life. These predominantly nuclear regulatory mechanisms converge on the function of the IGF2-H19 gene cluster on Chromosome 11 and ultimately affect IGF2 gene expression. Deregulation of such control checkpoints leads to the enhancement of IGF2 gene transcription and/or transcript stabilization, ultimately leading to IGF-II peptide overproduction. This type of anomaly is responsible for the effects observed in terms of both abnormal fetal growth and increased cell proliferation, typically observed in pediatric overgrowth syndromes and cancer. We performed a review of relevant experimental work on the mechanisms affecting the human IGF2 gene at the epigenetic, transcriptional and transcript regulatory levels. The result of our work, indeed, provides a wider and diversified scenario for IGF2 gene activation than previously envisioned by shedding new light on its extended regulation. Overall, we focused on the functional integration between the epigenetic and genetic machinery driving its overexpression in overgrowth syndromes and malignancy, independently of the underlying presence of loss of imprinting (LOI). The molecular landscape provided at last strengthens the role of IGF2 in cancer initiation, progression and malignant phenotype maintenance. Finally, this review suggests potential actionable targets for IGF2 gene- and regulatory protein target-degradation therapies.

A 69-year-old female patient and a 70-year-old male patient were admitted to hospital with recurrent, severe hypoglycemic episodes and a typical manifestation of Whipple's triad. In the female, elevated levels of insulin, C‑peptide and pro-insulin together with pathological findings during a fasting test proved the presence of an insulinoma, which could be detected by Ga-68-DOTATOC-PET-CT in the pancreas. There was a very rare co-existence of a neuroendocrine Merkel cell carcinoma. In the male, levels of insulin and C‑peptide were suppressed and a diagnosis of paraneoplastic hypoglycemia by IGF‑2 secretion was made with increased glucose disposal in skeletal muscle proven by ¹⁸F‑FDG-PET-CT.

Alzheimer's disease (AD) is the most common form of dementia. Current AD treatments slow the rate of cognitive decline, but do not restore lost function. One reason for the low efficacy of current treatments is that they fail to target neurotrophic processes, which are thought to be essential for functional recovery. Bolstering neurotrophic processes may also be a viable strategy for preventative treatment, since structural losses are thought to underlie cognitive decline in AD. The challenge of identifying presymptomatic patients who might benefit from preventative treatment means that any such treatment must meet a high standard of safety and tolerability. The neurotrophic peptide insulin-like growth factor-2 (IGF2) is a promising candidate for both treating and preventing AD-induced cognitive decline. Brain IGF2 expression declines in AD patients. In rodent models of AD, exogenous IGF2 modulates multiple aspects of AD pathology, resulting in (1) improved cognitive function; (2) stimulation of neurogenesis and synaptogenesis; and, (3) neuroprotection against cholinergic dysfunction and beta amyloid-induced neurotoxicity. Preclinical evidence suggests that IGF2 is likely to be safe and tolerable at therapeutic doses. In the preventative treatment context, the intranasal route of administration is likely to be the preferred method for achieving the therapeutic effect without risking adverse side effects. For patients already experiencing AD dementia, routes of administration that deliver IGF2 directly access the CNS may be necessary. Finally, we discuss several strategies for improving the translational validity of animal models used to study the therapeutic potential of IGF2.

A 63-year-old man with spells of reduced consciousness in the morning and a giant abdominal mass presented to our institution for a second opinion. Investigation revealed non-diabetic hypoinsulinemic hypoglycemic events. Removal of the abdominal mass solved the hypoglycemia. Anatomopathological examination confirmed a solitary fibrous tumor (SFT). Doege-Potter syndrome was diagnosed. Doege-Potter syndrome is a potentially life-threatening rare paraneoplastic syndrome characterized by recurrent hypoinsulinemic hypoglycemia due to the overproduction of a prohormone form of insulin-like growth factor-II (pro-IGF-II) from a solitary fibrous tumor. First, we describe the clinical, laboratory and radiologic findings of the case. Second, a brief literature review on Doege-Potter syndrome is provided.

In proliferating cells and tissues a number of checkpoints (G1/S and G2/M) preceding cell division (M-phase) require the signal provided by growth factors present in serum. IGFs (I and II) have been demonstrated to constitute key intrinsic components of the peptidic active fraction of mammalian serum. In vivo genetic ablation studies have shown that the cellular signal triggered by the IGFs through their cellular receptors represents a non-replaceable requirement for cell growth and cell cycle progression. Retroactive and current evaluation of published literature sheds light on the intracellular circuitry activated by these factors providing us with a better picture of the pleiotropic mechanistic actions by which IGFs regulate both cell size and mitogenesis under developmental growth as well as in malignant proliferation. The present work aims to summarize the cumulative knowledge learned from the IGF ligands/receptors and their intracellular signaling transducers towards control of cell size and cell-cycle with particular focus to their actionable circuits in human cancer. Furthermore, we bring novel perspectives on key functional discriminants of the IGF growth-mitogenic pathway allowing re-evaluation on some of its signal components based upon established evidences.

A 9-year-old female spayed Brittany Spaniel presented for weakness and stumbling, and was diagnosed with severe hypoglycemia. An insulin to glucose ratio was not consistent with insulinoma as a cause for hypoglycemia. Diagnostic imaging (abdominal ultrasound and computed tomography) revealed a large left renal mass and a possible metastatic lesion in the right kidney. Glucagon therapy was initiated, but hypoglycemia was refractory to therapy. A left nephrectomy was performed and hypoglycemia subsequently resolved. Histopathology of the mass was consistent with nephroblastoma and immunohistochemistry for anti-insulin-like Growth Factor-2 (IGF-2) antibody revealed immunoreactivity in over 50% of the neoplastic cells. Chemotherapeutic treatment was initiated with a combined protocol of vincristine and doxorubicin. To the authors' knowledge, this is the first case report documenting the treatment of severe, refractory non-islet cell tumor-induced hypoglycemia in a dog, suspected to be secondary to an IGF-2 secreting nephroblastoma.

Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome caused by a tumor-producing high molecular weight form of insulin-like growth factor 2 (IGF2) known as big IGF2. The only curative treatment for this condition is surgical resection of the responsible tumors. However, this may not be feasible in cases with multiple metastases at diagnosis of NICTH, and no standard treatment strategy for multiple tumors has been established. The effects of pharmacological therapies including somatostatin analogs are often inefficient and remain difficult to predict.

A 68-year-old man was admitted to our hospital due to impaired consciousness and severe hypoglycemia. His medical history included diagnosis of a left temporal solitary fibrous tumor (SFT) at the age of 48 years, after which local recurrent and metastatic tumors were repeatedly resected. Four years before admission, multiple intraabdominal and subcutaneous tumors were detected and, being asymptomatic, were managed conservatively. Laboratory exam on admission demonstrated hypoglycemia accompanied with low serum insulin and IGF1 levels. Computed tomography (CT) scan revealed multiple intraabdominal and subcutaneous tumors increasing in size. Serum big IGF2 was detected on immunoblot analysis, and he was diagnosed as NICTH. In addition, tumor uptake was observed on ⁶⁸Ga-labelled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid-d-Phe¹-Tyr³-octreotide positron emission tomography/CT (DOTATOC-PET/CT). Since larger tumor is more suspicious about responsible producibility of big IGF2, we planned to resect large ones preferentially and reduce the amounts of residual tumors. Debulking surgery was performed by removing eleven intraabdominal tumors; the hypoglycemia was then completely corrected. Histological analyses revealed the resected tumors to be metastases of SFT having somatostatin receptor 2 expression. In immunoblot analysis, the resected tumors were found to be positive for big IGF2; serum big IGF2 was undetectable after surgery.

We present a case of NICTH with multiple metastatic SFTs. We strategically performed debulking surgery, which led to remission of hypoglycemia. This result demonstrates a pioneering practical solution for NICTH cases with multiple tumors. In addition, in cases of SFTs presenting with NICTH, positivity of DOTATOC-PET/CT as well as single-dose administration of octreotide may be predictive of the efficacy of somatostatin-based therapy.

Despite multiple intracranial and extracranial relapses associated with a widely metastatic meningeal solitary fibrous tumor (formerly classified as hemangiopericytoma), a 66-year-old type 2 diabetic man was first diagnosed with paraneoplastic hypoglycemia 23 years after the original diagnosis and 12 years after the onset of extracranial metastatic disease. An enlarging mass entirely replacing the left kidney measuring 11.6 × 10 × 28 cm, which had not been locally treated before, was considered to be the putative source of IGF-2 excess. The insulin-like effects of IGF-2 not only ameliorated his long-standing type 2 diabetes mellitus, but also caused spontaneous fasting hypoglycemia. The physiopathology, clinical manifestations, diagnostic approach, and treatment of non-islet cell tumor hypoglycemia are briefly discussed here. Palliative tumor debulking improved the hypoglycemia by day 11 after radiation therapy and glucose monitoring with continuous glucose monitoring system (Dexcom G6) facilitated the patient's management and gave him peace of mind.

To investigate the effects of insulin-like growth factor 2 (IGF2) on growth and glycolipid metabolism, as well as the underlying mechanism.

A mouse model of IGF2 overexpression was constructed to measure weight gain before adulthood, to obtain the values of adult glycolipid metabolism indicators in the peripheral blood and to detect the expression of genes in the IGF2 signaling pathway in different mouse tissues. The present study also explored the independent association between the IGF2 gene and macrosomia by detecting and comparing the expression levels of IGF2 mRNA/H19 RNA in maternal peripheral blood and fetal cord blood of 26 human pregnancies.

In the mouse model, weights of the IGF2-overexpressing mice were significantly higher than those of the control mice at the age of 5-10 weeks. The glucose concentration, total cholesterol and high-density lipoprotein cholesterol (HDL-C) levels of IGF2-overexpressing mice were significantly lower than those of wild-type (WT) mice. Compared with the WT mice, the expression of H19 was significantly decreased in the pancreas and IGF1R was significantly decreased in the muscle of mice with IGF2 overexpression. The expression levels of STAT3 and AKT2 showed significant decrease in liver, muscle and increase in muscle of IGF2-overexpressing mice, respectively. GLUT2 expression showed significant increase in liver, kidney, muscle and decrease in pancreas of mice with IGF2 overexpression. This study also found that in normal mothers with the similar clinical characteristics, IGF2 expression in the maternal peripheral blood and fetal cord blood is an independent factor influencing macrosomia.

IGF2 expression was independently correlated with the occurrence of macrosomia, and overexpression of IGF2 significantly increased the weights of mice at the age of 5-10 weeks and significantly affected the values of adult glycolipid metabolism indicators, which might be the result of changes in the IGF2-IGF1R-STAT3/AKT2-GLUT2/GLUT4 pathway. These findings might suggest that IGF2 plays an important role in growth and glycolipid metabolism during both pregnancy and postnatal development.

Solitary fibrous tumors (SFTs) are a rare group of spindle cell neoplasm of submesothelial origin with malignant potential and can present as hypoglycemia secondary to excess secretion of insulin-like growth factor II (IGF-II) from the tumor. Early diagnosis and treatment are very important in such cases to prevent hypoxic injury to the brain secondary to hypoglycemia. Here, we are presenting a case of a 45-year-old male patient, who presented with recurrent episodes of hypoglycemia spells, and later on, it was diagnosed that hypoglycemic spells were secondary to fibroma.