Hypoglycaemia in a 63-year-old female with a large, recurrent, metastatic gastrointestinal stromal tumour (GIST)

Clinical characteristics of gastrointestinal stromal tumors with hypoglycemia

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.

Big insulin-like growth factor 2-producing multiple solitary fibrous tumors treated with debulking surgery: A case report

BACKGROUND

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.

CASE DESCRIPTION

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.

CONCLUSION

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.

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.