Mechanisms and management of non-islet cell tumour hypoglycaemia in gastrointestinal stromal tumour: case report and a review of published studies

Neoadjuvant Imatinib Therapy for Gastrointestinal Stromal Tumors Associated With Non-islet Cell Tumor Hypoglycemia (NICTH): A Case Report

Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome characterized by insulin-like growth factor-2 (IGF-2) release, often associated with diverse tumor types. Gastrointestinal stromal tumors (GISTs), sarcomatous lesions of the gastrointestinal tract, are rarely associated with NICTH. We present a unique case of a 58-year-old patient diagnosed with a GIST exhibiting recurrent hypoglycemia suggestive of NICTH. Despite normal IGF-2 levels, the IGF-2/IGF-1 ratio supported the NICTH diagnosis, which was confirmed histologically. Imaging revealed a large intraperitoneal mass. Hypoglycemia was managed with high-dose dextrose and hydrocortisone. Treatment with the tyrosine kinase inhibitor, imatinib, was initiated. Surprisingly, imatinib not only reduced the tumor size but also improved hypoglycemia. The study highlights the complexities in managing NICTH and its underlying causes. Current diagnostic limitations, treatment modalities, and unexpected therapeutic responses challenge standard approaches. This emphasizes the need for personalized oncological strategies.

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.

Doege-Potter Syndrome: A Presumptive Case of Metastatic Hemangiopericytoma with Persistent Hypoglycemia in a 27-Year-Old Male

Doege-Potter syndrome (DPS) is a rare paraneoplastic condition characterized by hypoinsulinemic hypoglycemia from a solitary fibrous tumor. The underlying mechanism is the secretion of a prohormone form of insulin-like growth factor II (IGF-II) by the tumor, which causes decreased release of glucose into the circulation. We report the case of a 27-year-old Filipino male with presumptive DPS from a recurrent right temporo-zygomatic hemangiopericytoma (HPC). The complexity of DPS requires a multidisciplinary approach. Early screening for metastases from HPC may prevent the undesirable sequelae of the disease process.

Diagnosis and treatment of a caecal mucocoele in a dog

An 11-year-old male intact Staffordshire Bull terrier was referred for diabetic ketoacidosis. Abdominal ultrasonographic examination revealed a 5 cm × 2 cm intraluminal caecal mass-like structure. Exploratory laparotomy and typhlectomy were subsequently performed. Histopathology of the caecal mass-like structure was consistent with a caecal mucocoele, defined as a cystic dilation of the caecal lumen with stasis of mucus. This lesion has been previously described in humans, where it is termed an appendiceal mucocoele. The patient was euthanased 58 days post-operatively due to unrelated diabetic complications.

A Case of Non-Islet Cell Tumor Hypoglycemia (NICTH) Associated with Gastrointestinal Stromal Tumor (GIST)

Patient: Male, 60

Final Diagnosis: Non-islet cell tumor hypoglycemia (NICTH) associated with gastrointestinal stromal tumor (GIST)

Symptoms: Hypoglycemia

Medication: —

Clinical Procedure:—

Specialty: Gastroenterology and Hepatology

A case of extragastrointestinal stromal tumor complicated by severe hypoglycemia: a unique presentation of a rare tumor

BACKGROUND

Non-Islet Cell Tumor Hypoglycemia (NICTH) is a rare paraneoplastic cause of hypoglycemia arising from excess tumor production of insulin-like growth factor. The objective of this report is to describe an unusual case of Extragastrointestinal Stromal Tumor (EGIST) associated NICTH.

CASE PRESENTATION

A 64 year-old African female was brought to the emergency room with a 1-month history of recurrent syncope, weight loss, and abdominal bloating. Serum blood glucose was discovered to 39 mg/dL, when insulin, proinsulin, and C-peptide were suppressed. Computed tomography scan revealed a diffuse extraintestinal metastatic disease process, and a biopsy confirmed the diagnosis of an Extragastrointestinal Stromal Tumor (EGIST). IGF-I and II levels were 27 ng/ml and 262 ng/ml respectively, and the ratio of IGF-II to IGF-I was calculated as 9.7:1, suggestive of IGF-II-mediated NICTH. Acutely, the patient's hypoglycemia resolved with dextrose and glucagon infusion. Long-term euglycemia was achieved with prednisone and imatinib therapy.

CONCLUSIONS

NICTH should be considered when hypoglycemia occurs in the setting of low serum insulin levels. Whereas definitive treatment of EGIST involves surgical resection, immunotherapy with tyrosine kinase inhibitors and corticosteroids have been shown to alleviate hypoglycemia in cases where surgery is delayed or not feasible.

Hypoglycemia Associated with a Gastrointestinal Stromal Tumor Producing High-molecular-weight Insulin Growth Factor II: A Case Report and Literature Review

A 61-year-old woman with multiple metastatic and unresectable gastrointestinal stromal tumors (GISTs) was referred for investigation of refractory hypoglycemia that developed four months before this hospitalization. On admission, her fasting plasma glucose was 38 mg/dL despite 10% glucose infusion. Investigations revealed that her serum C-peptide, insulin and growth hormone levels were suppressed, and big insulin-like growth factor II was observed. She was diagnosed with non-islet cell tumor hypoglycemia, which resolved after glucocorticoid treatment. Clinicians should thus be vigilant to identify hypoglycemia in patients with large metastatic GISTs because glucocorticoid therapy is useful even if the GIST is inoperable.

Management of non-islet-cell tumor hypoglycemia: a clinical review

CONTEXT

Non-islet cell tumor hypoglycemia (NICTH) is a rare but serious paraneoplastic syndrome in which a tumor secretes high molecular weight IGF-II, causing hypoglycemia. Complete tumor resection is curative but is often delayed or unfeasible. There is no clear "standard of care" for managing these patients.

EVIDENCE ACQUISITION

PubMed searches were conducted for: "non-islet-cell tumor hypoglycemia," "NICTH," "Doege-Potter," "Doege-Potter syndrome," "high molecular weight IGF-II," and "big IGF-II." Relevant articles were reviewed in detail. We limited our review to English-language articles, focusing on 1988-2013 (corresponding with the elucidation of the pathophysiology of NICTH).

EVIDENCE SYNTHESIS

The available literature exists as case reports or small case series, with a void of higher-order treatment studies. Thus, an evidence-based approach to data synthesis was difficult. Nevertheless, the available literature is presented objectively with an attempt to describe clinically useful trends and findings in the management of NICTH.

CONCLUSIONS

Appropriate identification of NICTH and prompt and complete tumor resection represents ideal management. However, when prompt resection is not feasible, iv glucose or dextrose often does not suffice to prevent hypoglycemia. In such cases, we suggest consideration of local antitumor therapies for disease control and trial of glucocorticoids alone or in combination with GH. Continuous glucagon infusion can be successful if the patient has a positive response to a glucagon stimulation test, and parenteral nutrition may allow higher glucose delivery, but both are limited by the need for continuous iv infusion. Diazoxide and octreotide have no role in NICTH.

Tumors, IGF-2, and hypoglycemia: insights from the clinic, the laboratory, and the historical archive

Tumors of mesenchymal and epithelial origin produce IGF-2, which activates pathways in the tumors. In a minority of patients, the tumors (hepatomas, fibromas, and fibrosarcomas are the most common among many) release into the circulation enough IGF-2-related peptides to mimic the fasting hypoglycemia characteristic of patients with insulin-producing islet-cell tumors. Rarely, markedly elevated IGF-2 levels produce somatic changes suggestive of acromegaly. Typically, the elevated IGF-2 levels are associated with suppressed plasma levels of insulin, IGF-1, and GH. Complicating the pathophysiology are the IGF binding proteins (IGFBPs) that can bind IGF-2 and IGF-1, modifying hormone metabolism and action. IGFBP concentrations are often altered in the presence of these tumors. At the cellular level, the 3 hormone-related ligands, IGF-2, IGF-1, and insulin, all bind to 4 (or more) types of IGF-1 receptor (IGF-1R) and insulin receptor (IR). Each receptor has its own characteristic affinity for each ligand, a tyrosine kinase, and overlapping profiles of action in the target cells. The IGF-2R, in addition to binding mannose-6-phosphate-containing proteins, provides an IGF-2 degradation pathway. Recent evidence suggests IGF-2R involvement also in signal transduction. Surgery, the treatment of choice, can produce a cure. For patients not cured by surgery, multiple therapies exist, for the tumor and for hypoglycemia. Potential future therapeutic approaches are sketched. From 1910 to 1930, hypoglycemia, insulin, insulinomas, and non-islet-cell tumors were recognized. The latter third of the century witnessed the emergence of the immunoassay for insulin; the IGFs, their binding proteins, and assays to measure them; and receptors for the insulin-related peptides as well as the intracellular pathways beyond the receptor. In closing, we replace non-islet-cell tumor hypoglycemia, an outdated and misleading label, with IGF-2-oma, self-explanatory and consistent with names of other hormone-secreting tumors.

The insulin-like growth factor system and sarcomas

Sarcomas are a diverse group of malignant mesenchymal tumours arising from bone and soft tissues. The identification of critical cellular signalling pathways in sarcomas is an important issue for the development of new targeted therapies. This review highlights the experimental and clinical evidence supporting the role of the insulin-like growth factor (IGF) signalling system in the cellular transformation and progression of several types of sarcoma, including rhabdomyosarcoma, synovial sarcoma, leiomyosarcoma, Ewing's sarcoma and osteosarcoma. Preclinical data suggest that the IGF system could be a promising target for therapy in these sarcomas. Currently, therapies interrupting IGF signalling have been or are being developed. In recent phase 1 clinical studies with humanized monoclonal antibodies directed against IGF receptor type 1 (IGF-1R), objective tumour responses were observed in several patients with Ewing's sarcoma, encouraging further clinical testing in Ewing's sarcoma and other sarcoma (sub)types. Moreover, the occasional occurrence of paraneoplastic hypoglycaemia as a result of the secretion of incompletely processed forms of pro-IGF-II by sarcomas is discussed.

Insulin-like growth factors and insulin-like growth factor-binding proteins in relation to disease status and incidence of hypoglycaemia in patients with a gastrointestinal stromal tumour

OBJECTIVE

Patients with a gastrointestinal stromal tumour (GIST) suffering from non-islet cell tumour-induced hypoglycaemia (NICTH), being associated with increased plasma levels of pro-insulin-like growth factor (IGF)-IIE[68-88], have been reported occasionally. We studied the clinical relevance of pro-IGF-IIE[68-88] and other IGF-related proteins in GIST patients.

PATIENTS AND METHODS

Twenty-four patients were included. Plasma samples were collected before 1 week and median 5 months after start of treatment with imatinib, and levels of IGF-I, total IGF-II, pro-IGF-IIE[68-88], insulin-like growth factor-binding protein (IGFBP)-2, -3 and -6 were determined. GIST specimens from 17 patients and tumour cyst fluid from two patients were analysed for IGF-II and IGFBP-2.

RESULTS

Before treatment and/or during follow-up, 3 of 24 (13%) patients showed increased plasma levels of pro-IGF-IIE[68-88]. All three developed NICTH. Overall, patients with metastatic disease, elevated serum lactate dehydrogenase activity or total tumour size >12 cm had the highest pro-IGF-IIE[68-88] levels. Most patients had increased plasma IGFBP-2 levels and these levels were significantly higher in patients with progressive disease. (Pro-)IGF-II was expressed in 82% of GISTs and IGFBP-2 only in one case.

CONCLUSION

We identified pro-IGF-IIE[68-88] as a marker that may be used in the surveillance of GIST.

Unusual combination of paraneoplastic manifestations in a patient with metastatic gastrointestinal stromal tumor (GIST)

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors of the gastrointestinal tract. Activating mutations in tyrosine kinase receptors KIT or platelet-derived growth factor receptor alpha (PDGFRA) are the main mechanisms causing the disease. Patients generally present with non-specific symptoms, while a number of tumors are discovered incidentally and may be metastatic at the time of diagnosis. Aggressive GISTs have a defined pattern of metastasis to the liver or throughout the abdomen, or both. Though GISTs rarely present systemic or isolated paraneoplastic reactions, a few cases have been reported in the literature. We present the case of a 54-year-old patient with metastatic GIST at diagnosis and the emergence of paraneoplastic manifestations during follow-up.