Mechanisms of tumor-induced hypoglycemia with intraabdominal hemangiopericytoma

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.

Pasireotide: A Novel Treatment for Tumor-Induced Hypoglycemia Due to Insulinoma and Non-Islet Cell Tumor Hypoglycemia

Tumor-induced hypoglycemia is a serious disorder most commonly caused by insulinoma or non-islet cell tumor hypoglycemia (NICTH). The hypoglycemia can be severe and refractory to conventional therapy, leading to significant morbidity and mortality. The objective of this work is to describe a series of challenging cases in which refractory, tumor-induced hypoglycemia was shown to respond to the use of pasireotide, a second-generation somatostatin receptor ligand. We describe the clinical and biochemical features of 3 patients with tumor-induced hypoglycemia due to an occult insulinoma, malignant insulinoma, and non-islet cell tumor hypoglycemia. In these 3 individuals, the hypoglycemia remained refractory to guideline-recommended medical therapy, such as diazoxide, nonpasireotide somatostatin analogues, and glucocorticoids. Pasireotide was substituted to attenuate the refractory hypoglycemia for each patient. The addition of pasireotide led to prompt improvement in the frequency and severity of hypoglycemic episodes for each tumor-induced hypoglycemia patient. We demonstrate the successful treatment of 3 individuals with refractory, tumor-induced hypoglycemia with pasireotide. We offer the first reported use of pasireotide for the successful treatment of nonmalignant insulinoma and non-islet cell tumor hypoglycemia.

Insulin-like growth factor-II and bioactive proteins containing a part of the E-domain of pro-insulin-like growth factor-II

Insulin-like growth factor (IGF)-II is considered to function as an important fetal growth factor, which is structurally and functionally related to IGF-I and proinsulin. At least in vitro, IGF-II actions are mediated through the IGF-I receptor and to a lesser extent the insulin receptor. After birth, the function of IGF-II is less clear although in adults the serum level of IGF-II exceeds that of IGF-I several fold. The IGF-II gene is maternally imprinted, with exception of the liver and several parts of the brain, where it is expressed from both alleles. The regulation, organization, and translation of the IGF-II gene is complex, with five different putative promotors leading to a range of noncoding and coding mRNAs. The 180-amino acid pre-pro-IGF-II translation product can be divided into five domains and include a N-terminal signal peptide of 24 amino acid residues, the 67 amino acid long mature protein, and an 89 residues extension at the COOH terminus, designated as the E-domain. After removal of the signal peptide, the processing of pro-IGF-II into mature IGF-II requires various steps including glycosylation of the E-domain followed by the action of endo-proteases. Several of these processing intermediates can be found in the human circulation. There is increasing evidence that, besides IGF-II, several incompletely processed precursor forms of the protein, and even a 34-amino acid peptide (preptin) derived from the E-domain of pro-IGF-II, exhibit distinct biological activities. This review will focus on the current insights regarding the specific roles of the latter proteins in cancer, glucose homeostasis, and bone physiology. To address this topic clearly in the right context, a concise overview of the biological and biochemical properties of IGF-II and several relevant aspects of the IGF system will be provided.

Successful Multimodal Treatment of an IGF2-Producing Solitary Fibrous Tumor With Acromegaloid Changes and Hypoglycemia

Doege–Potter syndrome with acromegaloid facial changes is extremely rare. Uncooked cornstarch along with glucocorticoids have been used as supportive care in patients with non–islet cell tumor hypoglycemia (NICTH). Preoperative embolization of hepatic solitary fibrous tumors (SFT) with NICTH has yielded unsatisfactory results. Herein we present the case of a 61-year-old man with a 3-month history of severe frequent hypoglycemic episodes and acromegaloid facial changes. During a spontaneous hypoglycemia (26 mg/dL), laboratory values showed a hypoinsulinemic pattern with low levels of GH, IGFPB3, and an IGF2/IGF1 ratio of 8.5:1. Cross-sectional imaging revealed a large (16 × 13 × 11 cm) hepatic tumor, and cytology was consistent with SFT. A preoperative right portal embolization was performed in an effort to induce normal remnant liver hypertrophy to allow for safe tumor resection. After the procedure, uncooked starch treatment followed by prednisone was started, achieving complete remission of hypoglycemic episodes in the preoperative setting. He subsequently underwent partial hepatectomy. The histologic diagnosis was compatible with a potentially malignant SFT. The patient had an excellent outcome with complete remission of hypoglycemia, improvement of facial acromegaloid changes, and no further evidence of disease. To our knowledge, this is the first case of a patient with Doege–Potter syndrome with acromegaloid facial changes induced by a potentially malignant liver SFT, treated successfully with a multimodal approach consisting of uncooked cornstarch, low-dose prednisone, preoperative embolization, and complete surgical resection. The use of cornstarch and low-dose glucocorticoids may be an adequate treatment in advance of undergoing surgery.

Design and Clinical Evaluation of a Novel Low-Glucose Prediction Algorithm with Mini-Dose Stable Glucagon Delivery in Post-Bariatric Hypoglycemia

BACKGROUND

Postbariatric hypoglycemia (PBH) is a complication of bariatric surgery with limited therapeutic options. We developed an event-based system to predict and detect hypoglycemia based on continuous glucose monitor (CGM) data and recommend delivery of minidose liquid glucagon.

METHODS

We performed an iterative development clinical study employing a novel glucagon delivery system: a Dexcom CGM connected to a Windows tablet running a hypoglycemia prediction algorithm and an Omnipod pump filled with an investigational stable liquid glucagon formulation. Meal tolerance testing was performed in seven participants with PBH and history of neuroglycopenia. Glucagon was administered when hypoglycemia was predicted. Primary outcome measures included the safety and feasibility of this system to predict and prevent severe hypoglycemia. Secondary outcomes included hypoglycemia prediction by the prediction algorithm, minimization of time below hypoglycemia threshold using glucagon, and prevention of rebound hyperglycemia.

RESULTS

The hypoglycemia prediction algorithm alerted for impending hypoglycemia in the postmeal state, prompting delivery of glucagon (150 μg). After observations of initial incomplete efficacy to prevent hypoglycemia in the first two participants, system modifications were implemented: addition of PBH-specific detection algorithm, increased glucagon dose (300 μg), and a second glucagon dose if needed. These modifications, together with rescue carbohydrates provided to some participants, contributed to progressive improvements in glucose time above the hypoglycemia threshold (75 mg/dL).

CONCLUSIONS

Preliminary results indicate that our event-based automatic monitoring algorithm successfully predicted likely hypoglycemia. Minidose glucagon therapy was well tolerated, without prolonged or severe hypoglycemia, and without rebound hyperglycemia.

Malignant phyllodes tumor of the breast presenting with hypoglycemia: a case report and literature review

Phyllodes tumors are rare fibroepithelial neoplasms that account for less than 1% of all breast tumors and are typically found in middle-aged women. Phyllodes tumors that present with hypoglycemia are even rarer. No one morphologic finding is reliable in predicting the clinical behavior of this tumor. Surgery has been the primary mode of treatment to date. However, the extent of resection and the role of adjuvant radiotherapy or chemotherapy are still controversial. Here, we present a challenging case of malignant phyllodes tumor of the breast associated with hypoglycemia, and review the literature regarding clinical findings, pathologic risk factors for recurrence, and treatment recommendations.

Recurrent hypoglycemia triggered by sorafenib therapy in a patient with hemangiopericytoma

Targeted therapy has been proven to be one of the most effective cancer treatments. However, some endocrine disorders can occur during treatment with targeted agents. We report the case of a patient who exhibited a wax and wane pattern of hypoglycemia that was attributed to sorafenib therapy. A 32-year-old woman with metastatic hemangiopericytoma visited the emergency department in a stuporous state. Nonhyperinsulinemic hypoglycemia was diagnosed, was exacerbated shortly after sorafenib therapy, and was improved by the cessation of sorafenib with additional glucocorticoid therapy. Patients with metastatic hemangiopericytoma should be carefully monitored with particular attention to hypoglycemia when sorafenib therapy is initiated.

The oncological emergency case: paraneoplastic hypoglycemia in metastatic breast cancer - case report and brief review of the literature

BACKGROUND

Paraneoplastic hypoglycemia is a rare syndrome amoung tumorous diseases. It is often associated with a paraneoplastic secretion of 'big' insulin-like growth factor-II.

METHODS

We describe this syndrome in a 60-year-old patient with advanced breast cancer 8 years after primary diagnosis.

RESULTS AND CONCLUSION

This non-islet cell tumor-induced hypoglycemia may be the only evidence for an otherwise clinically occult disease progression. Fast diagnosis and appropriate acute and causal treatment concepts should be part of oncological management.

Recurrent meningeal hemangiopericytoma with multiple metastasis and hypoglycemia: a case report

Aims. We report on the unusual case of a 43-year-old man who developed recurrent meningeal hemangiopericytoma and presented with hypoglycemia 6 years after excision of the tumor. Methods and Results. We utilized computed tomography to assure multiple tumor metastasis and cranial recurrence of previous meningeal hemangiopericytoma and clinical laboratory tests and immunohistochemical staining to characterize this case. Magnetic resonance imaging and computed tomography showed the recurrent tumor at original torcular site was increased in size. Abnormal low levels of growth hormone, insulin, and insulin-like growth factor-I except insulin-like growth factor-II were detected in the serum. By immunohistochemistry, the neoplastic cells characteristically express diffusely CD99, bcl2, and variable CD34. After radio- and chemotherapy, serum glucose level of the patient returned to normal. Conclusions. Comparing other brain tumors, meningeal hemangiopericytoma has a higher recurrent and metastatic rate, but this tumor with hypoglycemia is very rare.

Solitary fibrous tumors and so-called hemangiopericytoma

We have reviewed the literature data regarding the spectrum of tumors including solitary fibrous tumor and hemangiopericytoma with special focus on definition of the disease, discussion of the criteria for malignancy, and the key elements of standard treatment of localized disease. We have discussed the emerging concepts on the tumor biology and the different systemic treatments (chemotherapy and molecular-targeted therapies).

The role of insulin-like growth factor system in soft tissue sarcomas: from physiopathology to targeted therapeutic approaches

Purpose/Results. Although surgical, chemo- and radiotherapeutic treatment regimens in patients with soft tissue sarcomas have constantly been refined over the past two decades, the survival rate for these patients is rather low.

Discussion. There is a great need to investigate the mechanisms for oncogenesis and to identify the factors involved in malignant transformation in sarcomas. Among these factors, IGFs are thought to play a pivotal role as progression factors in various types of sarcomas. The dysregulation of the IGF-II synthesis, e.g. by loss of imprinting which occurs in most types of sarcomas, is a permissive effect through the suppression of cell death. In addition, cells that overexpress the type I IGF receptors are more susceptible to transformation by oncogenes. As TP53 suppresses the activity of IGF-II P3 and P4, as well as the type I IGF receptor promoter, mutations of TP53 in sarcomas may alternatively lead to the activation of these factors. Finally, the phenomenon of non-islet cell tumour hypoglycaemia that occurs in patients with sarcomas, and which is related to the secretion of IGF-II prohormones, is discussed. Future therapeutic strategies may be based upon the application of antibodies or antisense oligonucleotides directed against the type I IGF receptors, with the common goal of inducing apoptosis in sarcoma cells. Ultimately, these and other therapeutic approaches may lead to a better outcome in patients suffering from sarcoma.

Glucagon treatment for post-gastric bypass hypoglycemia

Hyperinsulinemic hypoglycemia is a recently described complication of Roux-en-Y gastric bypass (RYGB). We hypothesized that glucagon administration would help maintain normal postprandial plasma glucose concentrations by stimulating hepatic glucose output, and if so, represent a new therapeutic option for postbypass hypoglycemia. In this study, we compared the insulin and glycemic response to a mixed meal with and without concomitant glucagon infusion in a patient with severe recurrent hypoglycemia after RYGB. Although effective in transiently raising postprandial plasma glucose values, glucagon infusion was also associated with higher insulin concentrations, and failed to prevent symptomatic hypoglycemia. This case demonstrates that glucagon may have limited clinical utility in the treatment of post-RYGB hyperinsulinemic hypoglycemia.

A rare cause of hypoglycaemia

We describe the case of a 77-year-old man who was admitted with recurrent episodes of altered behaviour. These episodes were related to insulin-like growth factor II (IGF-II) mediated hypoglycaemia. Imaging revealed a large retroperitoneal mass and he underwent debulking surgery uneventfully. Histopathology revealed a solitary fibroma with intense immunostaining positive for CD34 and vimentin, suggesting a mesenchymal origin of the tumour. Later he received chemo/radiotherapy and is on prednisolone with abatement of hypoglycaemic episodes.