The surgical management of insulinomas in children

Hyperinsulinemic Hypoglycemia Due to an Insulinoma in a 2-Year-Old Child

Insulinomas are rare insulin-secreting tumors that most commonly affect adults. A 26-month-old child presented to her local emergency department with severe hypoglycemia. Initial workup was consistent with hyperinsulinemic hypoglycemia. Over the course of 10 months, multiple therapies for hyperinsulinism (HI) were trialed without significant benefit. Genetic testing for genes associated with HI was negative. At age 35 months, the patient was transferred to our center for further treatment. She underwent several imaging tests that revealed a lesion on her pancreas concerning for an insulinoma. The patient underwent surgical intervention to enucleate the lesion. Histopathological review of the specimen confirmed a benign, well-circumscribed insulinoma. A postoperative fasting test proved the patient was cured and she was discharged without the need for further glucose monitoring.

Multifocal Insulinoma as the Unique Presenting Feature of Multiple Endocrine Neoplasia Type 1 in an Adolescent

INTRODUCTION

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited disorder defined by the presence of two of the following endocrinopathies: primary hyperparathyroidism, anterior pituitary tumors, and duodenopancreatic neuroendocrine tumors (NETs). NETs, which can secrete hormones including insulin, gastrin, and glucagon, among others, are common in patients with MEN1 and are a major cause of morbidity and premature death. NETs are more common later in life, with very few cases described in children. Here, we describe a unique case of an adolescent with multifocal pancreatic NETs as the single presenting feature of MEN1.

CASE PRESENTATION

A 13-year-old healthy male presented with severe weakness, altered mental status, and syncope in the setting of a venous blood glucose (BG) of 36 mg/dL. Workup showed an elevated insulin level (14 μIU/mL) when BG was 39 mg/dL with positive response to glucagon, concerning for hyperinsulinism. Diazoxide and chlorothiazide were started but not well tolerated secondary to emesis. Three suspected NETs were identified by magnetic resonance imaging and 68-Ga DOTATATE PET-CT imaging, including the largest, a 2.1 cm mass in the pancreatic head. A fourth mass in the pancreatic tail was identified via intraoperative ultrasound. All lesions were successfully enucleated and excised, and glucose levels normalized off diazoxide by post-op day 2. While the primary lesion stained for insulin and somatostatin by immunofluorescence (IF), consistent with his clinical presentation, the additional tumors expressed glucagon, somatostatin, pancreatic polypeptide, and chromogranin A but were negative for insulin. Genetic testing confirmed a pathogenic heterozygous mutation in MEN1 (c.969C>A, p.Tyr323). He had no other signs of MEN-associated comorbidities on screening.

DISCUSSION/CONCLUSION

This case demonstrates that young patients with MEN1 can present with multifocal NETs. These NETs may have polyhormonal expression patterns despite a clinical presentation consistent with one primary hormone. Our patient had clinical symptoms and laboratory evaluation consistent with an insulinoma but was found to have four NETs, each with different IF staining patterns. Advanced preoperative and intraoperative imaging is important to identify and treat all present NETs. Moreover, serum hormone levels pre- and posttreatment could help evaluate whether NETs are actively secreting hormones into the bloodstream or simply expressing them within the pancreas. Finally, this case highlights the importance of genetic testing for MEN1 in all young patients with insulinomas.

INTRODUCTION

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant inherited disorder defined by the presence of two of the following endocrinopathies: primary hyperparathyroidism, anterior pituitary tumors, and duodenopancreatic neuroendocrine tumors (NETs). NETs, which can secrete hormones including insulin, gastrin, and glucagon, among others, are common in patients with MEN1 and are a major cause of morbidity and premature death. NETs are more common later in life, with very few cases described in children. Here, we describe a unique case of an adolescent with multifocal pancreatic NETs as the single presenting feature of MEN1.

CASE PRESENTATION

A 13-year-old healthy male presented with severe weakness, altered mental status, and syncope in the setting of a venous blood glucose (BG) of 36 mg/dL. Workup showed an elevated insulin level (14 μIU/mL) when BG was 39 mg/dL with positive response to glucagon, concerning for hyperinsulinism. Diazoxide and chlorothiazide were started but not well tolerated secondary to emesis. Three suspected NETs were identified by magnetic resonance imaging and 68-Ga DOTATATE PET-CT imaging, including the largest, a 2.1 cm mass in the pancreatic head. A fourth mass in the pancreatic tail was identified via intraoperative ultrasound. All lesions were successfully enucleated and excised, and glucose levels normalized off diazoxide by post-op day 2. While the primary lesion stained for insulin and somatostatin by immunofluorescence (IF), consistent with his clinical presentation, the additional tumors expressed glucagon, somatostatin, pancreatic polypeptide, and chromogranin A but were negative for insulin. Genetic testing confirmed a pathogenic heterozygous mutation in MEN1 (c.969C>A, p.Tyr323). He had no other signs of MEN-associated comorbidities on screening.

DISCUSSION/CONCLUSION

This case demonstrates that young patients with MEN1 can present with multifocal NETs. These NETs may have polyhormonal expression patterns despite a clinical presentation consistent with one primary hormone. Our patient had clinical symptoms and laboratory evaluation consistent with an insulinoma but was found to have four NETs, each with different IF staining patterns. Advanced preoperative and intraoperative imaging is important to identify and treat all present NETs. Moreover, serum hormone levels pre- and posttreatment could help evaluate whether NETs are actively secreting hormones into the bloodstream or simply expressing them within the pancreas. Finally, this case highlights the importance of genetic testing for MEN1 in all young patients with insulinomas.

Novel Use of Dasiglucagon, a Soluble Glucagon Analog, for the Treatment of Hyperinsulinemic Hypoglycemia Secondary to Suspected Insulinoma: A Case Report

INTRODUCTION

Hyperinsulinemic hypoglycemia is the most common cause of persistent hypoglycemia in children and adults. In adolescents and adults, hyperinsulinemic hypoglycemia is most frequently caused by an insulin-producing tumor.

CASE PRESENTATION

A 17-year-old, previously healthy male presented with recurrent and severe episodes of hypoglycemia. Diagnostic evaluation was consistent with hyperinsulinemic hypoglycemia, and an insulinoma was suspected. Multiple imaging studies and surgical exploration failed to identify a lesion. Over the course of months, the patient was found to be refractory to conventional medical interventions.

CONCLUSION

Upon approval from the US Food and Drug Administration and the Institutional Review Board, the patient was treated with dasiglucagon, a novel soluble glucagon analog, under a single-patient Investigational New Drug. The patient has tolerated the medication and has been able to achieve appropriate glycemic control.

Diagnostic work-up and advancement in the diagnosis of gastroenteropancreatic neuroendocrine neoplasms

Neuroendocrine neoplasms (NENs) are a heterogeneous group of neoplasms ranging from well-differentiated, slowly growing tumors to poorly differentiated carcinomas. These tumors are generally characterized by indolent course and quite often absence of specific symptoms, thus eluding diagnosis until at an advanced stage. This underscores the importance of establishing a prompt and accurate diagnosis. The gold-standard remains histopathology. This should contain neuroendocrine-specific markers, such as chromogranin A; and also, an estimate of the proliferation by Ki-67 (or MIB-1), which is pivotal for treatment selection and prognostication. Initial work-up involves assessment of serum Chromogranin A and in selected patients gut peptide hormones. More recently, the measurement of multiple NEN-related transcripts, or the detection of circulating tumor cells enhanced our current diagnostic armamentarium and appears to supersede historical serum markers, such as Chromogranin A. Standard imaging procedures include cross-sectional imaging, either computed tomography or magnetic resonance, and are combined with somatostatin receptor scintigraphy. In particular, the advent of ¹¹¹In-DTPA-octreotide and more recently PET/CT and ⁶⁸Ga-DOTA-Octreotate scans revolutionized the diagnostic landscape of NENs. Likewise, FDG PET represents an invaluable asset in the management of high-grade neuroendocrine carcinomas. Lastly, endoscopy, either conventional, or more advanced modalities such as endoscopic ultrasound, capsule endoscopy and enteroscopy, are essential for the diagnosis and staging of gastroenteropancreatic neuroendocrine neoplasms and are routinely integrated in clinical practice. The complexity and variability of NENs necessitate the deep understanding of the current diagnostic strategies, which in turn assists in offering optimal patient-tailored treatment. The current review article presents the diagnostic work-up of GEP-NENs and all the recent advances in the field.

Insulinoma in an adolescent female with weight loss: a case report and literature review on pediatric insulinomas

Summary

Insulinomas are a rare cause of persistent hypoglycemia in a previously healthy child. In addition to symptoms of hypoglycemia, individuals with insulinomas usually present with a history of incessant caloric intake and weight gain due to a constant need to counter hypoglycemia. In addition to an extensive review of the literature, we report the first case of an insulinoma coexisting with reduced appetite secondary to anorexia nervosa in an adolescent female.

Learning points

Eliciting a detailed family history is important in hypoglycemia cases. Obtaining a thorough dietary intake, weight history, and menstrual cycles (in females) and considering a psychiatric consultation for an eating disorder when indicated. Although rare in the pediatric population, multiple endocrine neoplasia type 1 syndrome should be considered in the evaluation of children and adolescents with hypoglycemia who also have a family history of pituitary, pancreatic, and/or parathyroid endocrinopathies.

Multiple Endocrine Neoplasia in Childhood: An Update on Diagnosis, Screening, Management and Treatment

Multiple endocrine neoplasia (MEN) is a group of heterogenous syndromes characterized by the occurrence of two or more endocrine gland tumors in a patient or related individuals in the same family. They are inherited in an autosomal dominant fashion and are highly penetrant. There are three types of MEN syndromes: MEN type 1 (MEN1), MEN type 2 (MEN2), and MEN type 4 (MEN4). MEN2 is further divided into MEN2A, MEN2B (formerly known MEN3), and familial medullary thyroid carcinoma (FMTC). Although MEN syndromes are rare, it is crucial to identify individuals at risk for potentially life-threatening neoplasias. This review article provides an update on each MEN syndrome, its genetics, diagnosis, and management in children.

Persistent Hypoglycemia in Seven-year-old Saudi Child: A Case Report

Hypoglycemia is a frequent problem in infants and children, causing a significant dilemma to reach the correct diagnosis and perform the appropriate management. Congenital hyperinsulinism is the most common cause of hypoglycemic hyperinsulinemia in infants and is due to beta-cell hyperplasia caused by genetic defects. This is a well-known genetically and clinically heterogeneous condition causing severe hypoglycemia in infants. Insulin-secreting tumors (insulinoma) are rare findings during childhood. In contrast, insulinoma is the most common form of endogenous hypoglycemic hyperinsulinemia in the adult population. Here we present a successful diagnosis and treatment of a nine-year-old Saudi child who presented for the first time with severe episodes of hypoglycemia at age seven. Critical samples at the time of hypoglycemia confirmed the associated hyperinsulinemia state. Initially, the child responded well to anti-insulin medications at small doses, but with time the disease became progressive in severity requiring a high dose of anti-insulin medications, frequent glucagon injections, and hospital admission for intravenous dextrose infusion. After two years of seeking therapy in many hospitals, the final diagnosis was confirmed to be an insulinoma, which was removed surgically, resulting in a complete cure and full recovery. Here we report the first published case of insulinoma in a young child aged < 15 years old in Saudi Arabia, their disease course, final diagnostic steps, and curative therapy. We conclude that hypoglycemia in children is challenging in terms of diagnosis and management. Although insulinoma is very rare in children, it requires significant time and effort by a pediatrician, pediatric endocrinologist, patients, and parents to reach the final diagnosis and carefully preserve the integrity of the neurological state of those children.

Surgical treatment of congenital hyperinsulinism

A multidisciplinary approach to patients with congenital hyperinsulinism (HI) can distinguish focal from diffuse HI, localize focal lesions, and permit partial pancreatectomy with cure in almost all focal patients. Surgery does not cure diffuse disease but can help prevent severe hypoglycemia and brain damage. Surgery can be curative for insulinoma and for some cases of atypical HI.

Treatment patterns and outcomes for pancreatic tumors in children: an analysis of the National Cancer Database

PURPOSE

Pancreatic tumors are rare in children and limited data are available regarding incidence, treatment, and outcomes. We aim to describe patient and tumor characteristics and to report on survival of these diseases.

METHODS

Children with pancreatic tumors were queried from the National Cancer Database (2004-2014). The association between treatment and hazard of death was assessed using Kaplan-Meier method and Cox regression model.

RESULTS

We identified 109 children with pancreatic tumors; 52% were male and median age at diagnosis was 14 years. Tumors were distributed as follows: pseudopapillary neoplasm (30%), endocrine tumors (27%), pancreatoblastoma (16%), pancreatic adenocarcinoma (16%), sarcoma (6%) and neuroblastoma (5%). Seventy-nine patients underwent surgery, of which 76% achieved R0 resection. Most patients (85%) had lymph nodes examined, of which 22% had positive nodes. Five-year overall survival by tumor histology was 95% (pseudopapillary neoplasm), 75% (neuroblastoma), 70% (pancreatoblastoma), 51% (endocrine tumors), 43% (sarcoma), and 34% (adenocarcinoma). On multivariable analysis, surgical resection was the strongest predictor of survival (HR 0.26, 95% CI 0.10-0.68, p < 0.01).

CONCLUSION

Overall survival of children with pancreatic tumors is grim, with varying survival rates among different tumors. Surgical resection is associated with improved long-term survival.

Surgical treatment of congenital hyperinsulinism: Results from 500 pancreatectomies in neonates and children

BACKGROUND

Congenital Hyperinsulinism (HI) causes severe hypoglycemia in neonates and children. We reviewed our experience with pancreatectomy for the various types of HI.

METHODS

From 1998 to 2018, 500 patients with HI underwent pancreatectomy: 246 for focal HI, 202 for diffuse HI, 37 for atypical HI (16 for Localized Islet Nuclear Enlargement [LINE], 21 for Beckwith-Wiedemann Syndrome), and 15 for insulinoma. Focal HI neonates were treated with partial pancreatectomy. Patients with diffuse HI who failed medical management underwent near-total (98%) pancreatectomy. Atypical HI patients had pancreatectomies tailored to the PET scan and biopsy findings.

RESULTS

The vast majority of pancreatectomies for focal HI were < 50%, and many were 2%-10%. 97% of focal HI patients are cured. For diffuse disease patients, 31% were euglycemic, 20% were hyperglycemic, and 49% required treatment for hypoglycemia; the incidence of diabetes increased with long-term follow-up. All 15 insulinoma patients were cured.

CONCLUSIONS

Our approach to patients with focal HI can distinguish focal from diffuse HI, localize focal lesions, and permit partial pancreatectomy with cure in almost all focal patients. Surgery does not cure diffuse disease but can help prevent severe hypoglycemia and brain damage. Surgery can be curative for insulinoma and for some cases of atypical HI.

LEVEL OF EVIDENCE

Level IV.

Insulinoma: A Rare Cause of Hypoglycemia in Childhood

Patient: Male, 11

Final Diagnosis: Insulinoma

Symptoms: Dizziness • psychological issues

Medication: —

Clinical Procedure: —

Specialty: Endocrinology and Metabolic

Robotic enucleation for pediatric insulinoma with MEN1 syndrome: a case report and literature review

Background

A patient with a rare pediatric insulinoma and MEN1 syndrome was treated by robotic enucleation surgery.

Case presentation

We present a case of a 9-year-old girl presenting with repeated loss of consciousness, concomitant with a pale face, palpitations, and convulsions, which had persisted for 2 years and had been aggravated during the previous 2 months. She was previously misdiagnosed with epilepsy in another hospital. We further examined her while she was hospitalized. By combining her medical history and imaging examination and lab test results, a diagnosis of insulinoma was confirmed. Sanger-directed sequencing on a peripheral blood sample revealed an MEN1 gene mutation, indicating pediatric insulinoma with MEN1 syndrome. The patient underwent minimally invasive insulinoma enucleation surgery under the Da Vinci robot-assisted system with intraoperative ultrasound (IOUS) connected. The surgery was successfully completed within 65 min, and the girl recovered well postoperatively and no longer experienced symptoms of hypoglycemia.

Conclusion

This is the first report of a case of pediatric insulinoma treated using robotic enucleation. This experience demonstrates the feasibility and safety of combining robotic surgery with the enucleation procedure as an excellent strategy for pediatric insulinoma.

A population-based analysis of a rare oncologic entity: Malignant pancreatic tumors in children

PURPOSE

To examine the clinicopathological characteristics and prognosis of pediatric patients with malignant pancreatic tumors in a population-based cohort.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant pancreatic tumors, diagnosed between 1973 and 2013. Kaplan-Meier analysis was performed to determine median and five-year overall survival (OS) rates. Univariate survival analysis was executed using the log-rank test. Cox proportional hazards model was used to identify variables independently associated with mortality.

RESULTS

A total of 114 patients with pancreatic malignancies were identified. Median patient age was 16years and the majority of patients were white (64%) females (61.4%). The most prevalent histologic subtype was neuroendocrine tumors (35.1%), whereas pancreatoblastoma was more common during the first decade of life (P<0.001). Distant metastases were noted in 41.7% of the patients, while 33.3% and 25% had localized and regional disease respectively. Five-year OS rates were 77%, 66.4% and 64.8% for patients with pancreatoblastoma, neuroendocrine and epithelial tumors respectively. No death was observed in the solid pseudopapillary tumor group. Only history of having cancer-directed surgery (CDS) was significantly associated with lower overall mortality (HR: 5.1, 95% CI: 2.1, 12.4).

CONCLUSION

Pancreatic malignancies are rare in children. Their prognosis is variable and only CDS was independently associated with superior survival.

EVIDENCE RATING/CLASSIFICATION

Prognosis study, Level II.

Insulinoma masquerading as a loss of consciousness in a teenage girl: case report and literature review

BACKGROUND

Hypoglycemia due to a pancreatic beta cell neoplasm - insulinoma, is uncommon with only a few cases described. We report on a previously healthy 15-year-old Hispanic female with insulinoma who presented with a loss of consciousness due to hypoglycemia unawareness.

CASE PRESENTATION

EM was first brought to the emergency department (ED) after she was found unresponsive at home with point of care (POC) glucose of 29 mg/dL(1.6 mmol/L) documented by emergency medical services (EMS) upon arrival. After treatment with dextrose and normal laboratory evaluation, including complete blood count, basal metabolic profile and urine drug screen, she was sent home with recommendations to follow-up the next day with an endocrinologist. Due to insurance issues, the family did not keep the appointment. Two days later, she returned to the ED with POC of 19 mg/dL (1.05 mmol/L). Detailed history review identified vague fatigue, excessive sleepiness, poor oral intake and weight gain for a 2-3 month period and no suspicion for drug, alcohol or prescription medication abuse. Family history of multiple endocrine neoplasia was negative. Physical examination revealed mild acanthosis nigricans and a body mass index of 32.8 kg/m² (98th percentile). Laboratory evaluation showed elevated insulin with low cortisol and growth hormone levels at the time of hypoglycemia. Abdominal magnetic resonance imaging revealed a pancreatic mass, also supported by ultrasound, computed tomography and positron emission tomography scans. The patient underwent a partial pancreatectomy with removal of a well-circumscribed insulinoma from the anterior-superior aspect of the pancreatic neck confirmed by histology. Hypoglycemia resolved post-operatively and she remained euglycemic during a 48-h cure fast. At her 3-month follow-up visit, she had no symptoms of hypoglycemia.

CONCLUSION

Documented hypoglycemia in an otherwise healthy adolescent should be fully investigated before discharging a patient. Even a short duration of symptoms should prompt, in-depth diagnostic evaluations to rule out a potentially life threatening diagnosis of insulinoma.

Recurrent insulinoma in a 10-year-old boy with Down's syndrome

An insulinoma is a rare tumour with an incidence of four cases per million per year in adults. The incidence in children is not established. There is limited literature available in children with insulinoma, and only one case is reported in association with Down’s syndrome in adults. Insulinoma diagnosis is frequently missed in adults as well as in children. The Whipple triad is the most striking feature although it has limited application in young children. Hypoglycaemia with elevated insulin, C-peptide and absent ketones is highly suggestive of hyperinsulinism. We present a case of 10-year-old boy with Down’s syndrome with recurrent insulinoma. He was initially misdiagnosed as having an adrenal insufficiency and developed cushingoid features and obesity secondary to hydrocortisone treatment and excessive sugar intake. The tumour was successfully localised in the head of the pancreas with an MRI and octreotide scan on first presentation. Medical treatment with diazoxide and octreotide could not achieve normal blood glucose levels. The insulinoma was laparoscopically enucleated and pathological examination confirmed a neuroendocrine tumour. Subsequently, he had complete resolution of symptoms. He had a recurrence after 2 years with frequent episodes of hypoglycaemia. The biochemical workup was suggestive of hyperinsulinism. MRI and PET scan confirmed the recurrence at the same site (head of the pancreas). He had an open laparotomy for insulinoma resection. The pathology was consistent with benign insulinoma, and subsequently, he had complete resolution of symptoms.

Sporadic Insulinoma Presenting as Early Morning Night Terrors

A 16-year-old boy with a recent diagnosis of night terrors was evaluated for recurrent early morning hypoglycemia after an early morning seizure. Evaluation in clinic with critical laboratories identified hyperinsulinemic hypoglycemia. Additional investigation revealed a sporadic insulinoma as the etiology of his hypoglycemia and all symptoms were resolved after pancreaticoduodenectomy. The importance of obtaining critical laboratory samples is highlighted and appropriate radiologic, medical, and pathologic testing is discussed. We additionally review the medical and surgical management of hyperinsulinemic hypoglycemia. A discussion of multiple endocrine neoplasia type 1 associated insulinomas is included as well. This case highlights the importance of considering hypoglycemia in the evaluation of night terrors and new-onset seizures.

Sporadic Insulinoma as a Rare Cause of Recurrent Hypoglycemia in Children

Insulinoma is a rare pancreatic tumor in children and adolescents. As a result of insulin hypersecretion, signs and symptoms are more commonly consequences of the pathophysiologic responses to hypoglycemia. According to rarity of this tumor in children and nonspecificity of clinical presentations, diagnosis of insulinoma in this group of patients is usually delayed. Early diagnosis is very important for preventing neurologic damage. In this case report, we present the case of a 10-year-old boy with signs and symptoms of hypoglycemia and final diagnosis of insulinoma.

Cross sectional and nuclear medicine imaging of pancreatic insulinomas

Insulinomas are rare neuroendocrine tumors which occur predominantly in the pancreas. Although majority of the insulinomas are benign, over-secretion of insulin by the tumor leads to debilitating hypoglycemic symptoms. The diagnosis is based on clinical and biochemical findings. After the diagnosis is made, the principal challenge lies in locating the tumor because most tumors are solitary and small in size. Locating the tumor is of paramount importance as complete surgical excision is the only curative treatment, and incomplete resection leads to persistence of symptoms. Different preoperative and intraoperative imaging techniques have been used with varying success rates for the insulinoma imaging. Besides localizing the tumor, imaging also helps to guide biopsy, detect metastatic lesions, and perform image-guided therapeutic procedures. This review will discuss the role of different Cross sectional and nuclear medicine imaging modalities in insulinomas.

Vague neuroglycopenic complaints camouflage diagnosis of adolescent insulinoma: a case report

Background

Insulinoma is a rare diagnosis in the general population with estimates of 1 in 250,000 people per year. Reports of these pancreatic islet cell tumors are even more unusual in children and adolescents. Chronic hypoglycemia due to an insulinoma often presents with neuroglycopenic symptoms that can easily be overlooked, especially in adolescents where nonspecific complaints are common. This may result in delayed diagnosis with prolonged periods of untreated hypoglycemia and associated complications. The rarity of pediatric insulinoma, vagueness of presenting symptoms, and challenge of tumor localization make insulinoma a true diagnostic quandary for clinicians.

Case Presentation

In this report, we present a 15-year-old female who visited her primary care provider complaining of intermittent episodes of altered mental status including fatigue, irritability, and poor concentration. Her outpatient management included routine laboratory studies, drug screening, electroencephalogram (EEG), valproic acid initiation, CT scan of the abdomen, and endoscopic ultrasound with documentation of hypoglycemia, but otherwise inconclusive results. The patient was admitted to a tertiary children’s hospital with severe refractory hypoglycemia 8 months after the initial evaluation. A serum critical sample was obtained and magnetic resonance imaging (MRI) of the abdomen performed which confirmed the presence of a pancreatic mass ultimately identified as an insulinoma. She went on to have surgical resection of her tumor resulting in complete resolution of her hypoglycemia and associated symptoms.

Conclusion

Within this report we demonstrate the importance of being vigilant for fasting hypoglycemia secondary to insulinoma even when the patient presents with nonspecific symptoms such as fatigue, irritability, or problems with concentration. If these neuroglycopenic complaints are unnoticed or misdiagnosed, patients with a potentially curable disease are put at risk of neurologic injury, or even death, due to untreated severe hypoglycemia.

Diagnostic Difficulties in a Pediatric Insulinoma: A Case Report

Insulinomas are functional neuroendocrine pancreatic tumors rarely encountered in pediatric pathology. Insulinomas are usually solitary and sporadic, but may occur in association with multiple endocrine neoplasia type 1. Whipple's triad-hypoglycemia, simultaneous compatible adrenergic and/or neurological signs, and relief of symptoms upon the administration of glucose-remains the fundamental diagnostic tool. We report a case of insulinoma in an 11-year-old boy with malnutrition and mild psychic retardation. History revealed neuroglycopenic symptoms associated with hypoglycemia that returned to normal values after glucose intravenous infusion; before admission in our unit, the levels of circulating insulin, as well as the abdominal ultrasound and abdominal computed tomography scan, were reported within normal range. During hospitalization in our service, the glycemic curves showed recurring low values associated with low glycated hemoglobin, positive fasting test, and elevated C-peptide. The pancreatic ultrasound was inconclusive, but the magnetic resonance imaging revealed a high signal focal area with a diameter of 1 cm, located in the tail of pancreas. Conventional enucleation of the lesion prompted a spectacular normalization of glucose metabolism and the alleviation of the main clinical symptoms. The child had a favorable evolution in the clinical follow-up, presenting with weight gain and progressive remission to complete disappearance of most symptoms-except for the mental impairments. Although in our case Whipple's triad was apparent from the beginning, the diagnosis was delayed due to the failure of conventional imaging methods in locating the tumor. Weight loss and mental impairment contributed to the diagnosis pitfalls. Pediatricians should be aware of confusing and nonspecific symptoms, especially when children with insulinoma present mental or neurological retardation. Despite the existence of medical regimens, surgery remains the gold standard for the therapeutic approach to this condition.

Laparoscope resection of retroperitoneal ectopic insulinoma: A rare case

Ectopic insulinoma is a very rare and dormant tumor. Here we report the case of a 79-year-old female who presented with repeated episodes of hypoglycemia and was diagnosed with insulinoma based on laboratory and imaging examinations. Computed tomography and positron emission tomography revealed a tumor in the retroperitoneum under and left of the hepatoduodenal ligament, which was resected successfully using a laparoscopic approach. Pathologic results revealed an ectopic insulinoma, which was confirmed immunohistochemically. Ectopic insulinomas are accompanied by hypoglycemia that can be misdiagnosed as drug- or disease-induced. These tumors are difficult to diagnose and locate, particularly in atypical cases or for very small tumors. Synthetic or targeted examinations, including low blood glucose, elevated insulin, proinsulin, and C-peptide levels, 48-h fasting tests, and relevant imaging methods should be considered for suspected cases of insulinoma. Surgery is the treatment of choice for patients with insulinoma, and laparoscopic resection is a feasible and effective method for select ectopic insulinoma cases.

d-Dimer Levels are Significantly Increased in Blood Taken From Varicose Veins Compared With Antecubital Blood From the Same Patient

d-Dimer is a prothrombotic biomarker and a very sensitive measure of endogenous fibrinolysis. It is used as a screening test for suspected deep vein thrombosis. This study investigated whether d-dimer levels were increased in the varicose veins of patients in comparison to their own arm samples. Patients, n = 24, 17 male, age 45 (25-91), C2-6, awaiting saphenous laser ablation were compared to matched controls, n = 24, 17 male, age 42 (24-89). Concurrent venous blood samples were taken from the arm and a lower calf/ankle (varicose) vein. The median (interquartile range) d-dimer (ng/mL) level was significantly greater in the ankle than in the arm blood of the same patient at 319 (164-631) versus 281 (167-562), P = .003, Wilcoxon. This did not occur in the controls at 269 (80-564) versus 262 (106-526), P = .361, Wilcoxon. The results indicate increased endogenous fibrinolysis in varicose veins compared with arm blood. This suggests there is more thrombotic activity or dissolution of formed subclinical fibrin thrombus which may explain the association of varicose veins with superficial vein thrombosis. This contrasts with earlier studies reporting a local reduction in fibrinolysis in venous disease.

Strengths and limitations of using 18fluorine-fluorodihydroxyphenylalanine PET/CT for congenital hyperinsulinism

¹⁸fluorine-fluorodihydroxyphenylalanine (FDOPA) PET/CT is currently the first-line imaging technique to distinguish between focal and diffuse forms of congenital hyperinsulinism (CHI) and to accurately localize focal forms. However, this technique has a number of limitations, mainly the very small size of focal forms or inversely a very large focal form mimicking a diffuse form, and misinterpretation of physiologic uptake masking hot spots or inversely mimicking focal forms. The other limitation is the limited availability of the radiopharmaceutical. FDOPA PET/CT has no recognized competitor to date among the available morphologic and functional imaging techniques. Other potential approaches using specific tracers for positron emission tomography (PET) are discussed, using radiopharmaceuticals specific for β cell mass or targeting somatostatin receptors. These radiopharmaceuticals can be labeled with gallium-68, a PET emitter readily available in PET centers equipped with 68Ge/68Ga generators.

Insulinoma in childhood: clinical, radiological, molecular and histological aspects of nine patients

BACKGROUND

Insulinomas are a rare cause of hyperinsulinaemic hypoglycaemia (HH) in children. The clinical features, investigations, management and histology of these rare pancreatic tumours in children have not been described in a large cohort of patients.

METHODS

We conducted a retrospective review of cases diagnosed between 2000 and 2012, presenting to two referral centres in the United Kingdom. Clinical, biochemical, imaging (magnetic resonance imaging (MRI) and 6-L-¹⁸F-fluorodihydroxyphenylalanine (¹⁸F-DOPA) PET/CT scanning) and histological data were collected.

RESULTS

Nine children (age range 2-14.5 years) were diagnosed during the study period at Great Ormond Street Hospital (n=5) and Royal Manchester Children's Hospital (n=4). The combination of abdominal MRI scan (7/8) and ¹⁸F-DOPA PET/CT scan (2/4) correctly localised the anatomical location of all insulinomas. Before surgery, diazoxide therapy was used to treat hypoglycaemia, but only four patients responded. After surgical resection of the insulinoma, hypoglycaemia resolved in all patients. The anatomical localisation of the insulinoma in each patient was head (n=4), uncinate process (n=4) and tail (n=2, one second lesion) of the pancreas. Histology confirmed the diagnosis of insulinoma with the presence of sheets and trabeculae of epithelioid and spindle cells staining strongly for insulin and proinsulin, but not for glucagon or somatostatin. Two children were positive for MEN1, one of whom had two separate insulinoma lesions within the pancreas.

CONCLUSIONS

We describe a cohort of paediatric insulinoma patients. Although rare, insulinomas should be included in the differential diagnosis of HH, even in very young children. In the absence of a single imaging modality in the preoperative period, localisation of the tumour is achieved by combining imaging techniques, both conventional and functional.