Severe paraneoplastic hypoglycemia in a patient with a gastrointestinal stromal tumor with an exon 9 mutation: a case report

Probable paraneoplastic leukocytosis in a dog with a gastrointestinal stromal tumor

A 9-year-old female spayed Boston Terrier presented for diagnostic investigation of lethargy, poor appetite, weight loss, and a marked leukocytosis. Significant muscle wasting and a palpable abdominal mass were present on physical examination. Abdominal imaging revealed the mass to be of small intestinal origin; consequently, an intestinal resection and anastomosis were performed without complication. The histopathologic diagnosis was a gastrointestinal stromal tumor, verified by immunohistochemical positivity to CD117 (KIT). Two weeks after discharge, the leukocytosis had resolved. Though the exact molecular mediator of the severe leukocytosis was undetermined, resolution following tumor removal suggests a paraneoplastic cause. To the authors' knowledge, this is the first reported case of probable paraneoplastic leukocytosis secondary to a gastrointestinal stromal tumor in the dog. Gastrointestinal tract imaging should be performed when this uncommon hematologic abnormality is present.

Non-islet cell tumor hypoglycemia associated with Gastrointestinal Stromal Tumor: Case report and review of the literature

Non-islet cell tumor hypoglycemia is an uncommon paraneoplastic phenomenon commonly associated with tumors of mesenchymal origin like gastrointestinal stromal tumors (GIST). It causes the release of insulin-like growth factor type II. GIST are frequently asymptomatic but can present with vague symptoms such as gastrointestinal bleeding, gastric pain, anorexia, nausea, and vomiting. We present an interesting case of A 62-year-old male with GIST tumor admitted for refractory hypoglycemia found to have non-islet cell tumor hypoglycemia which is a relatively uncommon cause of hypoglycemia.

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.

Novel case of a scleroderma-mimicking syndrome associated with gastrointestinal stromal tumour

We report a case of a 54-year-old man who developed an atypical systemic syndrome involving Raynaud’s phenomenon, pulmonary fibrosis and skin thickening. These features were initially suggestive of newly diagnosed scleroderma. However, he displayed atypical clinical features of same, antinuclear antibody was negative and symptoms were refractory to various immunosuppressive therapies. CT imaging revealed a gastric mass, which later proved to be a gastrointestinal stromal tumour (GIST). Resection of the GIST leads to minimal symptomatic improvement. Surveillance imaging 1 year later revealed metastatic deposits. He was subsequently initiated on imatinib therapy, which led to a rapid improvement in fibrotic changes within weeks. While there have been previous descriptions of paraneoplastic fibrotic disorders, this is the first description of a scleroderma mimic in the setting of a GIST. It highlights an important potential overlap in the pathogenesis of these disease processes and the potential efficacy of tyrosine kinase inhibitors for scleroderma-like fibrotic disorders.

Paraneoplastic syndromes and other systemic disorders associated with neuroendocrine neoplasms

Neuroendocrine paraneoplastic syndromes (PNS) consist of metabolic disorders that accompany benign and malignant neoplasms but remain unrelated to mass effects or invasion by the primary tumor or its metastases. The underlying pathogenesis responsible for PNS usual clinical presentation relies on aberrant production of protein hormones, proteins and other substances by the tumor. Prompt recognition of characteristic signs and symptoms combined with serological identification of key substances may result in early diagnosis of PNS and its underlying malignancy. For these reasons, healthcare professionals should familiarize themselves with tumor-induced hypercalcemia, syndrome of inappropriate antidiuretic hormone, carcinoid syndrome, virilisation syndrome, gynecomastia, acromegaly, Cushing syndrome, osteogenic osteomalacia, tumor-induced hypoglycemia, necrolytic migratory erythema, and watery diarrhea, hypokalemia and achlorydria syndrome. Medical awareness for PNS can improve patient outcomes through earlier administration of cancer therapy and treatment, better symptomatic relief and prolong overall survival.

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

MANAGEMENT OF ENDOCRINE DISEASE: Pathogenesis and management of hypoglycemia

Glucose is the main substrate utilized by the brain and as such multiple regulatory mechanisms exist to maintain glucose concentrations. When these mechanisms fail or are defective, hypoglycemia ensues. Due to these robust mechanisms, hypoglycemia is uncommon and usually occurs in the setting of the treatment of diabetes using glucose-lowering agents such as sulfonylureas or insulin. The symptoms of hypoglycemia are non-specific and as such it is important to confirm hypoglycemia by establishing the presence of Whipple's triad before embarking on an evaluation for hypoglycemia. When possible, evaluation of hypoglycemia should be carried out at the time of spontaneous occurrence of symptoms. If this is not possible then one would want to create the circumstances under which symptoms occur. In cases where symptoms occur in the post absorptive state, a 72-h fast should be performed. Likewise, if symptoms occur after a meal then a mixed meal study may be the test of choice. The causes of endogenous hyperinsulinemic hypoglycemia include insulinoma, post-bariatric hypoglycemia and noninsulinoma pancreatogenous hypoglycemia syndrome. Autoimmune hypoglycemia syndrome is clinically and biochemically similar to insulinoma but associated with high levels of insulin antibodies and plasma insulin. Other important causes of hypoglycemia include medications, non-islet cell tumors, hormonal deficiencies, critical illness and factitious hypoglycemia. We provide an overview of the pathogenesis and management of hypoglycemia in these situations.

Paraneoplastic Hypoglycaemia: A Rare Manifestation of Pelvic Gastrointestinal Stromal Tumour

Non-Islet Cell Tumour Induced Hypoglycaemia (NICTH), presenting with recurrent fasting hypoglycaemia is a very rare paraneoplastic syndrome. It usually presents with large metastatic mesenchymal tumours. NICTH secondary to Gastrointestinal Stromal Tumour (GIST) is even rarer. Diagnosis of NICTH is based on the low serum insulin level, low serum concentrations of Insulin Like Growth Factor (IGF-I) and IGF binding protein- III (IGFBP-III) in combination with elevated concentrations of pro-IGF-II. Various Immunohistochemical (IHC) markers are integral to diagnosis of GIST namely 2-deoxyglucose-6-phosphate phosphatase -1(DOG-1), Cluster Differentiation 34 (CD 34), Cluster Differentiation 117 (CD117). The management requires prompt intravenous hydration and glucose infusions followed by surgical resection. We hereby, report a rare case of a 65-year-old female with intractable fasting hypoglycaemia due to overproduction of "big" insulin-like growth factor II diagnosed to have pelvic GIST and managed by Steroids and Imatinib.

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.

Severe paraneoplastic hypoglycemia secondary to a gastrointestinal stromal tumour masquerading as a stroke

We report the case of a 70-year-old previously healthy female who presented acutely to the Accident and Emergency department with left-sided vasomotor symptoms including reduced muscle tone, weakness upon walking and slurred speech. Physical examination confirmed hemiparesis with VIIth nerve palsy and profound hepatomegaly. A random glucose was low at 1.7 mmol/l, which upon correction resolved her symptoms. In hindsight, the patient recalled having had similar episodes periodically over the past 3 months to which she did not give much attention. While hospitalized, she continued having episodes of symptomatic hypoglycaemia during most nights, requiring treatment with i.v. dextrose and/or glucagon. Blood tests including insulin and C-peptide were invariably suppressed, in correlation with low glucose. A Synacthen stimulation test was normal (Cort (0') 390 nmol/l, Cort (30') 773 nmol/l). A computed tomography scan showed multiple lobulated masses in the abdomen, liver and pelvis. An ultrasound guided biopsy of one of the pelvic masses was performed. Immunohistochemistry supported the diagnosis of a gastrointestinal stromal tumour (GIST) positive for CD34 and CD117. A diagnosis of a non islet cell tumour hypoglycaemia (NICTH) secondary to an IGF2 secreting GIST was confirmed with further biochemical investigations (IGF2=96.5 nmol/l; IGF2:IGF1 ratio 18.9, ULN <10). Treatment with growth hormone resolved the patient's hypoglycaemic symptoms and subsequent targeted therapy with Imatinib was successful in controlling disease progression over an 8-year observation period.

LEARNING POINTS

NICTH can be a rare complication of GISTs that may manifest with severe hypoglycaemia and neuroglucopenic symptoms.NICTH can masquerade as other pathologies thus causing diagnostic confusion.Histological confirmation of GIST induced NICTH and exclusion of other conditions causing hypoglycaemia is essential.Mutational analysis of GISTs should be carried out in all cases as it guides treatment decision.Tailored management of hypoglycaemia, in this case using growth hormone and targeted cyto-reductive therapy, minimizes the risk of possible life-threatening complications.

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.

Patterns of deregulation of insulin growth factor signalling pathway in paediatric and adult gastrointestinal stromal tumours

BACKGROUND

Data regarding the patterns and the mechanisms of deregulation of the insulin growth factor (IGF) pathway in adult and paediatric gastrointestinal stromal tumours (GISTs) are limited.

METHODS

We investigated the expression profiling of the genes encoding the main components of the IGF signalling pathway in 131 GISTs (106 adults, 21 paediatric and four young adults) and 25 other soft-tissue sarcomas (STS) using an Affymetrix U133A platform. IGF2 was investigated for loss of imprinting (LOI) whereas IGF1R was analysed for copy number aberration and mutation.

RESULTS

IGF2 was the most highly overexpressed gene of the IGF pathway in GIST. IGF2 expression was also significantly higher than in other STS. IGF2 expression was correlated to the age onset and mutational status of GIST. Indeed, IGF2 expression was significantly higher in the 'adult' group than in the 'paediatric' and 'young adult' groups. Among adult GIST, IGF2 expression was higher in tumours lacking Homo sapiens v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) or alpha-type platelet-derived growth factor receptor (PDGFRA) mutations in comparison with mutated cases. A trend for a higher expression of IGF2 in resistant GIST in comparison to responsive GIST was also found. Overexpression of IGF2 was not related to LOI. Conversely, the expression of the IGF1R gene was significantly higher in the paediatric group than in the adult group. No copy number gains or mutations of IGF1R were observed.

CONCLUSION

The IGF pathway is deregulated in GIST with distinct patterns according to age onset and mutational status. The IGF pathway may represent a therapeutic target in patients with primary or secondary resistance to imatinib.

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

INTRODUCTION

Non-islet cell tumour-induced hypoglycaemia (NICTH) is rare, with few cases reported in patients with gastrointestinal stromal tumour (GIST).

CASE REPORT

A 63-year-old Chinese female with known metastatic GIST presents with persistent hypoglycaemia. Investigations revealed a likely diagnosis of NICTH, and she underwent debulking surgery. There was complete resolution of her hypoglycaemia post-operatively

DISCUSSION

NICTH should be considered in patients with GIST and hypoglycaemia. Surgical debulking is recommended as part of the management of NICTH.

The emerging role of insulin-like growth factor 1 receptor (IGF1r) in gastrointestinal stromal tumors (GISTs)

Recent years have seen a growing interest in insulin-like growth factor 1 receptor (IGF1R) in medical oncology. Interesting data have been reported also on IGF1r in gastrointestinal stromal tumors (GISTs) especially in children and in young adult patients whose disease does not harbour mutations on KIT and PDGFRA and are poorly responsive to conventional therapies. However, it is too early to reach conclusions on IGF1R as a novel therapeutic target in GIST because the receptor's biological role is still to be defined and the clinical significance in patients needs to be studied in larger studies. We update and comment the current literature on IGF1R in GISTs and discuss the future perspectives in this promising field.

Membranous nephropathy associated with gastrointestinal stromal tumour: a case report

Membranous nephropathy (MN) is a common cause of nephrotic syndrome in older adults. The association of MN with neoplasia has been controversial, but several recent studies have shown increase incidence of cancer in patients with MN [1]. We report a case of a 49-year-old male with severe nephrotic syndrome and concomitant jejunal gastrointestinal stromal tumour (GIST). The combination of preoperative Imatinib mesylate chemotherapy and tumour excision was followed by complete resolution of proteinuria within 19 months, without specific treatment for MN. An association between MN and GIST has never previously been reported in the literature.

Expression of insulin-like growth factor 2 in mesenchymal neoplasms

The insulin-like growth factor (IGF) system plays an important role in the growth and development of cells and has been implicated in oncogenesis and tumor progression. Gene expression profiling studies on limited numbers of specimens have shown high expression of IGF2, encoding the activating ligand for this system, in gastrointestinal stromal tumors (GISTs) and in synovial sarcomas. This data may have concrete clinical implications, as several reports exist of patients with GISTs suffering from severe hypoglycemia, a predicted effect of IGF2. Furthermore, new drugs targeting IGF signaling are entering clinical trials. The purpose of this study is to survey IGF2 expression at the protein level on a broad number of mesenchymal tumors representing all major diagnostic classes. By immunostaining tissue microarrays, results were obtained for 51 diagnostic categories of bone and soft-tissue tumors representing 1288 cases. Distinct membranous and/or cytoplasmic IGF2 immunoreactivity was assessed according to published criteria. Solitary fibrous tumors had the highest expression. Of 20 tumor types represented by more than 10 cases, synovial sarcomas, myxoid liposarcomas, GISTs, malignant peripheral nerve sheath tumors, chondrosarcomas, undifferentiated pleomorphic sarcomas (MFH), Ewing's sarcomas and tenosynovial giant cell tumors showed high levels of expression in more than 20% of cases. Of the 445 GIST cases with clinical information, those with high expression of IGF2 had a significantly worse outcome than those with low or no expression. IGF2 protein expression among mesenchymal tumors is largely consistent with gene expression studies and suggests a potential for molecular therapy targeting the IGF signaling pathway system in these neoplasms.

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.

Insulin-like growth factor (IGF) 1 and 2 help to predict disease outcome in GIST patients

BACKGROUND

The expression of the insulin-like growth factor (IGF) system has never been studied in gastrointestinal stromal tumors (GISTs).

PATIENTS AND METHODS

We studied the immunohistochemical expression of IGF1 receptor (IGFR-I), IGF1 and IGF2 in 94 samples of GISTs. IGF1 and IGF2 expression was scored in three classes: negative (N), moderate (M) and strong (S), according to staining intensity and extent.

RESULTS

IGFR-I was overexpressed in all cases. IGF1 and IGF2 expression was absent in 25 and 48 cases, moderate in 29 and 16 cases and strong in 40 and 30 cases, respectively. Strong IGF1 expression significantly correlated with higher mitotic index (P = 0.0001), larger (P = 0.01), higher risk (P = 0.0002), metastatic (P = 0.0001) and relapsed (P = 0.04) GISTs. Strong IGF2 expression correlated with higher mitotic index (P = 0.05) and higher risk GISTs (P = 0.001). The Kaplan-Meier analysis (N versus M versus S) showed a significant worsening of the disease-free survival (DFS) with the increase of IGF1 (P = 0.02) and IGF2 (P = 0.02) expression. In the subgroup of patients with operated high-risk GISTs, there was a better trend in DFS for patients affected by GISTs with negative IGF1 and IGF2.

CONCLUSIONS

The expression of IGF1 and IGF2 seems to predict relapse in GIST patients.