Non-islet Cell Hypoglycemia: Case Series and Review of the Literature

Paraneoplastic hypoglycemia: An overview for optimal clinical guidance

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.

A Case of Nonislet Cell Tumor Hypoglycemia Due to Metastatic Salivary Myoepithelial Carcinoma

Background/Objective

Nonislet cell tumor hypoglycemia (NICTH) is an uncommon cause of hypoglycemia due to a relative surplus of insulin-like growth factor 2 (IGF-2) or its precursor molecule. The diagnosis is confirmed by an elevated ratio of IGF-2 to insulin-like growth factor 1 (IGF-1). Myoepithelial carcinoma (MECA) is a rare and aggressive salivary gland cancer that has not been previously associated with NICTH.

Case Report

A 63-year-old female with a past medical history of metastatic salivary MECA, type 2 diabetes mellitus previously on metformin, hypertension, and hypothyroidism presented to her oncologist for chemotherapy and was found to have a serum glucose of 30 mg/dL (reference: 65-99). She was admitted for further diagnostic work-up which revealed an insulin level of <1 μU/mL (reference: 3-25), C-peptide <0.5 ng/mL (reference: 1.1-4.3), IGF-1 of 15 ng/mL (reference: 41-279), and IGF-2 of 147 ng/mL (reference: 180-580) with an IGF-2:IGF-1 molar ratio of 10, consistent with NICTH. The patient's hypoglycemia unfortunately was quite resistant to treatment, requiring a combination of corticosteroids, continuous dextrose infusion, and somatostatin injections. The patient died 3 weeks after presenting with hypoglycemia.

Discussion

Salivary MRCAs commonly contain pleomorphic adenoma gene 1 oncogene rearrangements which are associated with increased IGF-2 production and may predispose patients to hypoglycemia.

Conclusion

This case demonstrates that NICTH can be associated with metastatic salivary MECA. The hypoglycemia in this scenario is challenging to manage and is associated with poor prognosis.

Recurrent Hypoglycemia in a 67-Year-Old Woman with CD5- Positive Diffuse Large B-Cell Lymphoma

Hypoglycemia is a rare complication of diffuse large B-cell lymphoma. We are presenting a case of 67-year-old woman presented to her primary care physician with fatigue and hyperhidrosis. Laboratory evaluation revealed a glucose level of 1.9 mmol/L. Computed tomographic scan of the abdomen and subsequent positron emission tomographic scan revealed extensive lymphadenopathy. The patient was then diagnosed with CD5-positive-diffuse large B-cell lymphoma and developed recurrent hypoglycemia despite continuous infusion of glucose. Following immunochemotherapy, hypoglycemia was resolved. Several explanations have been postulated but the exact pathophysiology is not well understood. Further investigation is warranted to more clearly define the pathophysiology of persistent hypoglycemia in patients with diffuse large B-cell lymphoma.

Non-islet cell tumor hypoglycemia that required immediate surgery after a long-term asymptomatic state: recommendation for early intervention

Summary

An 82-year-old woman with a 60-year history of a lung tumor presented with hypoglycemia. Non-islet cell tumor hypoglycemia (NICTH) was suspected; however, her hypoglycemia stabilized with supplemental food. She was discharged, based on her wishes, and planned to undergo surgery later. After discharge, the hypoglycemia worsened rapidly and required immediate resection. Postoperatively, the hypoglycemia resolved. Western immunoblot analysis confirmed the presence of big insulin-like growth factor 2, confirming NICTH. This patient experienced the rapid progression of symptoms after an unprecedentedly long-term asymptomatic state. Therefore, when NICTH is suspected, early intervention is recommended regardless of the presence of asymptomatic state.

Learning points

In patients with NICTH, the onset of hypoglycemia is usually within a year of tumor detection, and few reports regarding long-term asymptomatic NICTH have been documented. NICTH can cause rapidly progressive symptoms after a long-term asymptomatic state, as in this case, and an asymptomatic state does not preclude the necessity for intervention, especially when patients are at risk for malnutrition. Tumor resection is the only curative treatment for patients with NICTH, but there is no consensus regarding the timing of surgery. However, considering the possibility of rapid symptom progression, patients should be examined and treated in a timely manner.

From liver to hormones: The endocrine consequences of cirrhosis

Hepatocrinology explores the intricate relationship between liver function and the endocrine system. Chronic liver diseases such as liver cirrhosis can cause endocrine disorders due to toxin accumulation and protein synthesis disruption. Despite its importance, assessing endocrine issues in cirrhotic patients is frequently neglected. This article provides a comprehensive review of the epidemiology, pathophysiology, diagnosis, and treatment of endocrine disturbances in liver cirrhosis. The review was conducted using the PubMed/Medline, EMBASE, and Scielo databases, encompassing 172 articles. Liver cirrhosis is associated with endocrine disturbances, including diabetes, hypoglycemia, sarcopenia, thyroid dysfunction, hypogonadotropic hypogonadism, bone disease, adrenal insufficiency, growth hormone dysfunction, and secondary hyperaldosteronism. The optimal tools for diagnosing diabetes and detecting hypoglycemia are the oral glucose tolerance test and continuous glucose monitoring system, respectively. Sarcopenia can be assessed through imaging and functional tests, while other endocrine disorders are evaluated using hormonal assays and imaging studies. Treatment options include metformin, glucagon-like peptide-1 analogs, sodium-glucose co-transporter-2 inhibitors, and insulin, which are effective and safe for diabetes control. Established standards are followed for managing hypoglycemia, and hormone replacement therapy is often necessary for other endocrine dysfunctions. Liver transplantation can address some of these problems.

A systematic review of literature on Insulin-like growth factor-2-mediated hypoglycaemia in non-islet cell tumours

INTRODUCTION

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Unraveling the Whipple Triad: Non-Islet Cell Tumor-Induced Hypoglycemia

Tumor-induced hypoglycemia (TIH) is a rare paraneoplastic phenomenon resulting from several tumor types and mechanisms. Insulinomas are the most common cause of TIH. However, non-islet cell tumors can also trigger hypoglycemia by releasing insulin-like growth factor 2 (IGF-II) or its precursor. We present a case of a 56-year-old woman experiencing spontaneous hypoglycemia due to a pleural-based solitary fibrous tumor. Diagnostic evaluations revealed diminished C-peptide levels, increased IGF-II, and a 4-fold increase in the IGF-II: IGF-I ratio, indicative of non-islet cell tumor hypoglycemia. Localization imaging identified a left pleural mass, confirming the diagnosis. Preoperatively, the patient received intravenous dextrose and corticosteroids, but surgical resection was essential for the resolution of symptoms. The identified tumor, a benign solitary fibrous tumor, was successfully removed, leading to an immediate postoperative cessation of hypoglycemia. Six years post resection, the patient remains symptom free. Managing TIH necessitates an early diagnosis aiming for complete tumor resection, with alternative approaches considered when complete resection is not possible. This case highlights the importance of a systematic diagnostic and management approach for TIH, emphasizing the need to identify the underlying cause, particularly in people without diabetes.

A review on nondiabetic hypoglycemia from various causes: Case series report

RATIONALE

Hypoglycemia is common in patients with glucose regulation disorders and related diabetic treatments but is rare in nondiabetic patients. Severe hypoglycemia can cause harm to patients' cognition, consciousness, central nervous system, cardiovascular and cerebrovascular system, and even death. However, the most fundamental way to control hypoglycemia is to identify the cause and deal with the primary disease. This article introduces 3 cases of nondiabetic hypoglycemia with different causes, aiming to improve our understanding of nondiabetic hypoglycemia and improve the ability of early diagnosis and differential diagnosis.

PATIENT CONCERNS

Case 1 is a 19-year-old female with a history of recurrent coma, and magnetic resonance imaging and endoscopic ultrasound of the pancreas suggest insulinoma. Case 2 is a 74-year-old male with a history of viral hepatitis, and computerized tomography shows multiple nodules in the liver, which is diagnosed as liver cancer. Case 3 is a 39-year-old female with a history of taking methimazole, who tested positive for insulin antibodies, and was diagnosed with insulin autoimmune syndrome.

DIAGNOSIS

All 3 patients were diagnosed with nondiabetic hypoglycemia, but the causes varied, and included insulinoma, non-islet cell tumor-induced hypoglycemia, and insulin autoimmune syndrome.

INTERVENTIONS

Case 1 underwent pancreatic tail resection; case 2 refused anti-tumor treatment and received glucose injections for palliative treatment only; and case 3 stopped taking methimazole.

OUTCOMES

After surgery, the blood sugar in case 1 returned to normal, and the blood sugar in case 2 was maintained at about 6.0 mmol/L. The symptoms of hypoglycemia gradually improved in case 3 after stopping the medication.

LESSONS

Non-diabetic hypoglycemia requires further examination to clarify the cause, and the correct differential diagnosis can provide timely and effective treatment, improving the patient's prognosis.

Investigation and Causes of Spontaneous (Non-Diabetic) Hypoglycaemia in Adults: Pitfalls to Avoid

Although adult spontaneous (non-diabetic) hypoglycaemia is rare, its recognition is important for the preventative or curative treatment of the underlying cause. Establishing Whipple's triad-low blood glucose, neuroglycopaenia and resolution of neuroglycopaenia on increasing blood glucose levels to normal or above-is essential to verify hypoglycaemia. Awareness that hypoglycaemia may occur in severely ill patients is important for its prevention. Further investigation in such cases is unnecessary unless another cause of hypoglycaemia is suspected. Patients are often asymptomatic and normoglycaemic at review. Their history of medication, self-medication, access to hypoglycaemic drugs, alcohol use and comorbidity may provide aetiological clues. The investigation involves obtaining blood samples during symptoms for laboratory glucose measurement or provoking fasting or postprandial hypoglycaemia as directed by symptoms. If confirmed, insulin, c-peptide, proinsulin and beta-hydroxybutyrate are analysed in hypoglycaemic samples. These will classify hypoglycaemia due to non-ketotic hyperinsulinaemia, non-ketotic hypoinsulinaemia and ketotic hypoinsulinaemia, and direct investigations to identify the underlying cause. There are, however, many pitfalls that may mislabel healthy individuals as "hypoglycaemic" or misdiagnose treatable or preventable causes of spontaneous hypoglycaemia. Clinical acumen and appropriate investigations will mostly identify hypoglycaemia and its cause.

The metabolic effects of resumption of a high fat diet after weight loss are sex dependent in mice

Dietary restriction is a frequent strategy for weight loss, but adherence is difficult and returning to poor dietary habits can result in more weight gain than that previously lost. How weight loss due to unrestricted intake of a healthy diet affects the response to resumption of poor dietary habits is less studied. Moreover, whether this response differs between the sexes and if the insulin-like growth factor (IGF) system, sex dependent and involved in metabolic control, participates is unknown. Mice received rodent chow (6% Kcal from fat) or a high-fat diet (HFD, 62% Kcal from fat) for 4 months, chow for 3 months plus 1 month of HFD, or HFD for 2 months, chow for 1 month then HFD for 1 month. Males and females gained weight on HFD and lost weight when returned to chow at different rates (p < 0.001), but weight gain after resumption of HFD intake was not affected by previous weight loss in either sex. Glucose metabolism was more affected by HFD, as well as the re-exposure to HFD after weight loss, in males. This was associated with increases in hypothalamic mRNA levels of IGF2 (p < 0.01) and IGF binding protein (IGFBP) 2 (p < 0.05), factors involved in glucose metabolism, again only in males. Likewise, IGF2 increased IGFBP2 mRNA levels only in hypothalamic astrocytes from males (p < 0.05). In conclusion, the metabolic responses to dietary changes were less severe and more delayed in females and the IGF system might be involved in some of the sex specific observations.

Solitary fibrous tumor with IGF-II-induced non-islet cell tumor hypoglycemia: a case report and molecular characterization by next-generation sequencing

Background

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.

Case presentation

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.

Conclusion

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.

A Case Report of Doege-Potter Syndrome: A Rare Cause of Hypoglycemia in a Patient without Diabetes

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.

Case report: Severe, refractory hypoglycemia in a 9-year-old Brittany Spaniel with renal nephroblastoma

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.

Medical Nutrition Therapy and Other Approaches to Management of Post-bariatric Hypoglycemia: A Team-Based Approach

PURPOSE OF REVIEW

This manuscript provides a review of post-bariatric hypoglycemia (PBH) with a special focus on the role of the registered dietitian-nutritionist (RDN) and medical nutrition therapy (MNT) recommendations as foundational for management.

RECENT FINDINGS

As the number of bariatric surgeries rises yearly, with 256,000 performed in 2019, PBH is an increasingly encountered late complication. Following Roux-en-Y (RYGB) or vertical sleeve gastrectomy (VSG), about 1/3 of patients report symptoms suggestive of at least mild postprandial hypoglycemia, with severe and/or medically confirmed hypoglycemia in 1-10%. Anatomical alterations, changes in GLP1 and other intestinally derived hormones, excessive insulin response, reduced insulin clearance, impaired counterregulatory hormone response to hypoglycemia, and other factors contribute to PBH. MNT is the cornerstone of multidisciplinary treatment, with utilization of personal continuous glucose monitoring to improve safety when possible. While many individuals require pharmacotherapy, there are no currently approved medications for PBH. Increasing awareness and identification of individuals at risk for or with PBH is critical given the potential impact on safety, nutrition, and quality of life. A team-based approach involving the individual, the RDN, and other clinicians is essential in providing ongoing assessment and individualization of MNT in the long-term management of PBH.

IGF-2 mediated hypoglycemia and the paradox of an apparently benign lesion: a case report & review of the literature

BACKGROUND

Non-islet cell tumour hypoglycemia (NICTH) is rarely encountered in clinical practice. Insulin-like growth factor 2 (IGF2) is the most common cause of NICTH observed in the setting of mesenchymal and epithelial neoplasia. This is a paraneoplastic syndrome caused by IGF2 activation of the insulin receptor.

CASE PRESENTATION

An 80 year old female presented with a short history of recurrent episodes of confusion with laboratory confirmed hypoglycemia with a plasma glucose of 2.7 mmol/L on fasting which fulfilled Whipple's triad. Diagnostic clues to the aetiology at presentation include the fasting pattern of hypoglycemia, hypokalaemia and the absence of weight gain. A 72 hour fast with results showed early hypoglycemia and suppression of serum insulin, c-peptide, and proinsulin. Serum insulin antibody was not detected. Subsequent measurement of the serum IGF2:IGF1 ratio was elevated at 22.3 and consistent with IGF-2 mediated hypoglycemia and imaging studies demonstrated a pelvic mass. Dietary intervention and oral prednisolone abated hypoglycemia prior to surgery. Ultimately, hypoglycemia resolved following operative intervention and steroid therapy was successfully withdrawn. Histopathology was remarkable for dual neoplastic processes with uterine solitary fibrous tumour (SFT) confirmed as the source of IGF2 hypersecretion on IGF-2 immunohistochemistry and a coincidental invasive high grade serous carcinoma involving the fimbria of the right fallopian tube.

CONCLUSION

The paradox in this case is that the benign solitary fibrous tumour accounted for patient morbidity through secretion of IGF2 and without treatment, posed a mortality risk. This is despite the synchronous presence of a highly malignant fallopian tube neoplasm. This case reinforces the need for thorough clinical evaluation of hypoglycemia to allow prompt and definitive management.

Comparative Oncology: Management of Hepatic Neoplasia in Humans and Dogs

Primary hepatic neoplasia is uncommonly reported in dogs. Hepatocellular carcinoma (HCC) is the most frequent neoplasia identified in dogs and considerable effort has been committed towards identifying definitive and palliative treatment options. HCC is well recognized in humans as a sequelae of liver disease such as hepatitis or cirrhosis, while in dogs a similar link has failed to be fully elucidated. Management of HCC in people may be curative or palliative dependent on staging and transplant eligibility. Despite differences in etiology, there is substantial similarity between treatment options for liver neoplasia in human and veterinary medicine. The below summary provides a comparative discussion regarding hepatic neoplasia in dogs and people with a specific focus on HCC. Diagnosis as well as descriptions of the myriad treatment options will be reviewed.

Paraneoplastic syndromes in hepatocellular carcinoma: a review

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and a significant proportion (20-40%) of patients with HCC develop paraneoplastic syndromes (PNS). Despite this, there is a paucity of clinical evidence regarding PNS in HCC.

AREAS COVERED

A systematic search was performed to identify relevant case studies regarding PNS in HCC. Another search was conducted to identify studies that evaluated the impact of PNS on survival outcomes in HCC. Since there are currently no international guidelines for PNS in HCC, this review aims to provide comprehensive summaries and recommendations of PNS in HCC, including the pathophysiology, clinical features, diagnostic approach, and management, so that clinicians remain guided in caring for HCC patients with PNS. In general, PNS are associated with poorer survival outcomes and negative prognostic markers of HCC.

EXPERT OPINION

The presence of PNS has a significant influence on survival rates and clinical outcomes of patients with HCC. They contribute to significant morbidity, influencing patients' quality of life and fitness for curative and palliative therapies. Therefore, it is paramount for PNS to be integrated into routine investigations after diagnosing HCC to guide further management and prognostication of the disease.

IGF-2 INDUCED HYPOGLYCEMIA ASSOCIATED WITH LUNG SARCOMA

Hypoglycemia from a non-insulin-secreting extrapancreatic tumor is a paraneoplastic syndrome characterized by the tumor production of a substance with an insulin-like effect (insulin-like growth factor 1 or 2 - IGF 1 or 2). Diagnosis is confirmed by the determination of IGF-1 and IGF-2 and finding an elevated IGF - 2/IGF-1 ratio. The availability of these tests is limited in many laboratories, so prompt recognition and therapies are late. We present the case of a 70-year-old patient diagnosed with right lower lobe bronchopulmonary neoplasm who presented to the emergency department with an altered general condition and hypoglycemic coma. The evaluation revealed low levels of insulin and C-peptide along with an elevated IGF-2/IGF-1 ratio of more than 10, suggesting a diagnosis of lung sarcoma with production of IGF-2. Because the tumor could not be resected in this case, chemotherapy and radiotherapy were performed, along with glucocorticoid therapy to prevent recurrent hypoglycemia. In the case of a patient with lung sarcoma and recurrent hypoglycemia (especially severe hypoglycemia or coma), extrapancreatic non-hyperinsulinemic hypoglycemia should be determinate tumor IGF-2 secretion.

Non-islet cell tumor hypoglycemia in a patient with uterine carcinosarcoma

•Non-islet cell tumor hypoglycemia (NICTH) is a rare cause of hypoglycemia in patients with uterine carcinosarcoma.•Complete surgical resection is the first-line treatment for NICTH.•In patients with tumors not amenable to complete resection, partial resection can provide improvement in severe hypoglycemia.

Paraneoplastic Hypoglycemia Leading to Insulin Independence in a Patient With Type 1 Diabetes

Objective

Non–islet cell tumor hypoglycemia (NICTH) is an uncommon paraneoplastic syndrome associated with mesenchymal neoplasms such as gastrointestinal stromal tumors (GISTs). We report the case of a patient with type 1 diabetes (T1D) and recurrent GIST who not only required discontinuation of insulin therapy but also required continuous parenteral glucose infusions to prevent hypoglycemia.

Methods

A 59-year-old woman with a 24-year history of T1D and recurrent GIST presented with frequent episodes of symptomatic hypoglycemia despite continuous reductions in her insulin therapy. Laboratory workup revealed undetectable insulin and C-peptide, low insulin-like growth factor (IGF) 1, normal IGF-2, and an elevated IGF-2:IGF-1 ratio. Medical management with prednisone alone and, later, in combination with octreotide did not reduce hypoglycemic episodes. Eventually, during hospitalization for severe hypoglycemia, she was treated and discharged with continuous intravenous dextrose infusion. She ultimately required around-the-clock glucose infusions, which helped her maintain what she believed was an acceptable quality of life during her remaining weeks.

Discussion

NICTH is characterized by excessive tumor production of IGF-2 or pro-IGF-2, leading to unrestricted glucose uptake in peripheral tissues and hypoglycemia. A diagnosis of NICTH can be made on the basis of low IGF-1 levels in the plasma with normal or elevated IGF-2. Tumor resection is the most definitive treatment for NICTH.

Conclusion

This patient with T1D presented with resistant hypoglycemia due to recurrence of an enlarging GIST. She required discontinuation of all insulin therapy and continuous dextrose infusions to maintain euglycemia.

Lenvatinib in severe hypoglycemia associated with hepatocelular carcinoma

We present the case of a 24-year-old man with multicentric hepatocellular carcinoma over HBV cirrhosis treated with Sorafenib and Tenofovir. He comes to our center for repeated episodes of symptomatic hypoglycemia that cannot be managed with standard measures. After ruling out different possibilities, the suspicion of hypoglycemia due to a non-islet cell tumor was finally confirmed. Given the impossibility of a curative treatment due to a reduced functional reserve, Sorafenib was changed to Lenvatinib, thereby improving glycemic control.

Early Improvement of Non-islet Cell Tumor Hypoglycemia by Chemotherapy Using Lenvatinib in a Case with Type 2 Diabetes and Hepatocellular Carcinoma Producing Big IGF-II

A 77-year-old man was treated with a DPP-4 inhibitor for type 2 diabetes. Hypoglycemia occurred frequently, and an examination revealed a tumor with a maximum diameter of 140 mm in both lobes of the liver. Western immunoblotting detected a high-molecular-weight form of insulin-like growth factor-II, and non-islet cell tumor hypoglycemia was diagnosed. Although prednisolone 40 mg was started, hypoglycemia continued to occur frequently. Surgical tumor removal was not indicated, so lenvatinib was initiated. Hypoglycemia improved quickly, and the tumor shrank until it had partially disappeared. His condition continued to improve, and he was discharged.

Non-Islet Cell Tumor Hypoglycemia Caused by Recurrent Pelvic Solitary Fibrous Tumor

Non-islet cell tumor hypoglycemia is a rare paraneoplastic condition caused by an extra-pancreatic tumor. We report a rare case of hypoglycemia caused by a relapsing pelvic solitary fibrous tumor associated with Big-IGF-2 production.

A 72-year-old woman was admitted to our hospital because of loss of consciousness and hypoglycemia. She had a history of ovarian solitary fibrous tumor, which has relapsed. From investigation, serum levels of insulin and C-peptide were suppressed; IGF-1 was slightly reduced and IGF-2 was within the normal range, but the IGF-2: IGF-1 ratio was elevated, indicating the presence of Big-IGF-2 secreting non-islet cell tumor. Contrast-enhanced computed tomography (CT) showed a large pelvic mass. She was then submitted to surgical resection of the mass, which histologically proved to be a solitary fibrous tumor. Three months later, she remains asymptomatic.

Non-islet cell tumor hypoglycemia should be considered in the differential diagnosis of patients presenting with tumors and recurrent hypoglycemia.

Severe Non-Islet Cell Hypoglycemia From Ileum-Origin Gastrointestinal Stromal Tumor Producing Insulin-Like Growth Factor-2 in a Patient With Liver Cirrhosis Due to Chronic Hepatitis B

Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome, and NICTH associated with gastrointestinal stromal tumor (GIST) is even more rare. Herein, we describe a patient with severe NICTH due to GIST who had developed liver cirrhosis as a consequence of chronic hepatitis B. Although circulating insulin, C-peptide, and insulin-like growth factor-1 (IGF-1) levels were significantly decreased, in contrast to our expectations, the growth hormone (GH) level was slightly elevated. Steroid therapy with prednisolone appeared to be effective for the prevention of severe and continuous hypoglycemia.

Persistent hypoglycemia due to an IGF-II-secreting malignant pheochromocytoma: a case report and literature review

A malignant pheochromocytoma with IGF-II-mediated hypoglycemia is reported; although treatment was cumbersome and evolution unfortunate, this diagnosis must be kept in mind when dealing with NICTH's differential diagnosis.

Non-islet cell tumor hypoglycemia as an initial presentation of hepatocellular carcinoma coupled with end-stage liver cirrhosis: A case report and review of literature

BACKGROUND

Non-islet cell tumor hypoglycemia (NICTH) is a rare cause of persistent hypoglycemia seen in patients with hepatocellular carcinoma (HCC). It is likely to be underdiagnosed especially in the patients with poor hepatic function and malnutrition. Herein, we report a rare case of NICTH as the initial presentation of HCC in a patient with chronic hypoglycemia due to end-stage liver cirrhosis.

CASE SUMMARY

A 62-year-old male with chronic fasting hypoglycemia secondary to end-stage hepatitis C-related cirrhosis, presented with altered mental status and dizziness. He was found to have severe hypoglycemia refractory to glucose supplements. Imaging studies and biopsy discovered well differentiated HCC without metastasis. Further evaluation showed low insulin, C-peptide and beta-hydroxybutyrate along with a high insulin-like growth factor-2/insulin-like growth factor ratio, consistent with the diagnosis of NICTH. As patient was not a candidate for surgical resection or chemotherapy, he was started on prednisolone with some improvements in the glucose homeostasis, but soon decompensated after a superimposed hospital acquired pneumonia.

CONCLUSION

NICTH can occur as the sole initial presentation of HCC and is often difficult to correct without tumor removal. Clinicians should maintain high clinical suspicion for early recognition of paraneoplastic NICTH in patients at risk for HCC, even those with chronic fasting hypoglycemia in the setting of severe hepatic failure and malnutrition.