18F-DOPA PET/MRI With Carbidopa for the Diagnosis of Hyperinsulinemic Hypoglycemia in an Adolescent Patient.

Hyperinsulinism due to focal or diffuse pancreatic lesions causing recurrent episodes of hypoglycemia is rare in mid-childhood. There is no consensus on the gold-standard imaging method to diagnose focal insulin-producing lesions beyond infancy. A 14-year-old boy with a complex medical history and refractory epilepsy, presented with blood glucose (BG) of 52 mg/dL (2.9 mmol/L) (normal reference range: 70-100 mg/dL [3.9-5.6 mmol/L]) and increased seizure frequency. He failed a fast within 4 hours, with BG of 48 mg/dL (2.7 mmol/L) and insulin level of 4.6 µIU/mL (24.6 pmol/L) (diagnostic at the time of hypoglycemia >1.25 µU/mL [8.7 pmol/L]). Conventional imaging studies showed no pancreatic lesion. Fluorine-18-L-dihydroxyphenylalanine positron emission tomography/magnetic resonance imaging (18F-DOPA-PET/MRI) scan premedicated with carbidopa demonstrated intense focal 18F-DOPA uptake in the distal pancreatic tail. He underwent distal pancreatectomy. Histopathology showed focal pancreatic islet cell hyperplasia, with more than 90% of the neuroendocrine islet cells being positive for chromogranin and synaptophysin, with no loss of p57 staining. Genetic studies were negative for mutations in ABCC8, KCNJ11, GCK, or GLUD1 genes, multiple endocrine neoplasia (MEN) type 1, and Beckwith-Wiedemann syndrome. BG normalized after surgery. Seizure frequency improved. This case highlights the utility of 18F-DOPA PET/MRI imaging in diagnosing focal hyperinsulinism beyond infancy.

A case of insulinoma misidentified as schizophrenia due to its manifestation in neuropsychiatric symptoms.

Insulinomas can present with neuroglycopenic symptoms suggesting neuropsychiatric disorders, delaying diagnosis and treatment. We recently treated a 65-year-old woman with insulinoma who was misdiagnosed at her nearby psychiatric clinic as having schizophrenia because of personality changes and memory impairment; she was treated with brexpiprazole, which was discontinued due to persistence of the symptoms. Despite her relatively low casual plasma glucose (70 mg/dL), the physician at the psychiatric clinic did not investigate the possibility of hypoglycemia, partly because her HbA1c level (5.2%) was within normal range. After skipping lunch one day, she was found by her family to be unable to communicate properly. She was transported to the emergency room of our hospital, where intermittently scanning continuous glucose monitoring (isCGM) use permitted detection of the hypoglycemia and led to a diagnosis of insulinoma and successful resection. A 72-h fasting test established hyperinsulinemic hypoglycemia. Contrast-enhanced computed-tomography and endoscopic ultrasonography together with selective arterial calcium stimulation test revealed an insulin-secreting tumor in the tail of the pancreas. Surgical resection of the tumor corrected her glucose and insulin levels as well as eliminated the insulinoma neuropsychiatric symptoms. Pathological examination showed that the tumor was positive for chromogranin A, synaptophysin and insulin. It is, therefore, important for physicians to be aware that insulinomas can manifest as neuroglycopenic symptoms and to consider the possibility of hypoglycemia by careful medical interview and isCGM, especially when patients suspected of psychiatric disorders do not show the expected response to antipsychotic drugs. Supplementary Information: The online version contains supplementary material available at 10.1007/s13340-024-00722-9.

Diagnostic Modalities, Management Considerations, and Outcomes of Insulinoma: A Case Series from a Tertiary Care Centre.

Introduction: Insulinomas are rare, usually sporadic, and typically benign pancreatic neuroendocrine tumours. Pre-operative localization is challenging and evidence on comparative analysis of anatomic and scintigraphic modalities for pre-operative tumour localization is limited, even in contemporary series. Methods: The current study was designed to study the clinical features and management challenges of insulinomas managed at a tertiary care centre. Clinical features, diagnosis, imaging techniques, surgical procedures, and outcomes details were collated. Pre-operative imaging techniques (CT/MRI, nuclear scintigraphy) were compared with intraoperative and histopathological findings to assess their accuracy of localization. Results: Thirty-seven patients (15 females [42%]; median age 36 years [IQR 28-49]) were included in the study. In four patients (10.8%), the tumour occurred in the setting of multiple endocrine neoplasia type 1 (MEN 1) while the remaining were sporadic. The sensitivity of pre-operative localization was 61.5% (multiphasic CT), 66.6% (multiphasic MRI), 100% (68Ga Exendin-4 PET-CT), and 91.6% (EUS). Three patients with normal multiphasic CT had localization on 68Ga Exendin-4 PET-CT. The positive predictive value (PPV) of both Exendin-PET-CT and EUS was similar at 91.6% and 91.6%, respectively. All patients (except one with nesidioblastosis), who underwent enucleation or partial pancreatic resection, were cured. Conclusion: 68Ga Exendin-4 PET-CT based is a non-invasive imaging modality that has high sensitivity and PPV and can be used as a first-line imaging modality. The overall prognosis of these tumours is good with high cure rates attained following surgical resection.

Pancreatic masses in children: a single-center experience over two decades.

Pancreatic masses are extremely rare in pediatric patients, with limited data available. This lack of data makes the diagnosis and management of these tumors in children extremely challenging. Therefore, we aimed to describe the presentations, clinical course, and outcomes of children with pancreatic tumors at our center. A retrospective analysis was performed of all pediatric patients diagnosed with pancreatic masses between 2003 and 2022 in an academic freestanding children's hospital. Data including demographics, clinical presentation, workup, management, and subsequent morbidity and mortality were collected and aggregated. Furthermore, we reviewed cases of pancreatic tumor resections in the National Surgical Quality Improvement Program - Pediatric (NSQIP-P) database to identify common adverse outcomes and measures for quality improvement. In total, 17 patients were identified at our institution. Diagnoses included solid pseudopapillary (n = 9), gastrinoma (n = 1), rhabdomyosarcoma (n = 2), pancreatoblastoma (n = 2), and insulinoma (n = 1). Two patients did not have a histopathologic diagnosis and were excluded from subsequent analysis. Overall, 12 patients underwent surgical intervention, with the most common procedures being pancreaticoduodenectomy and distal pancreatectomy, and all 12 were known to be alive at last contact. There were 3 deaths, all due to complications related to metastatic disease. Furthermore, 30-day postoperative outcomes in the NSQIP-P dataset for pancreatic surgeries in pediatric patients are excellent, with negligible morbidity and no mortalities after the index surgery. CONCLUSIONS: Children with pancreatic tumors amenable to surgical resection appear to have adequate long-term survival. Short-term outcomes at diagnosis are excellent and mainly appear to be influenced by the presence of metastatic disease at initial presentation. WHAT IS KNOWN: • Pancreatic masses are a rare entity in children with limited data on their presentation, management and surgical outcomes. • Solid Pseudopapillary tumors are one of the most common pancreatic tumors in children with a fair prognosis after surgical intervention. WHAT IS NEW: • Surgical management of pediatric patients with pancreatic tumors is safe and effective in patients who do not have aggressive tumor types or metastatic disease. • Our case series provides a notable cohort of these pancreatic tumors with insight into the presentation, management and outcomes of five of these tumor types.

[Robotic enucleation of pancreatic insulinoma]. / Robot-assistirovannaya enukleatsiya insulinomy podzheludochnoi zhelezy.

We demonstrate robot-assisted treatment of a patient with benign pancreatic insulinoma. A 31-year-old patient suffered from attacks of weakness, numbness of the fingertips and «turbidity of consciousness¼ for 2 years. These symptoms occurred on an empty stomach and regressed after eating. We found pancreatic insulinoma. The patient underwent robotic enucleation of pancreatic tumor. Surgery time was 145 min. Postoperative period proceeded without complications. Hyperglycemia up to 10.5 mmol/l on the first postoperative day was followed by normalization after 4 days. The patient was discharged in 6 days after surgery. Minimally invasive robotic enucleation of insulinoma minimizes surgical trauma and provides precise resection of tumor. The key aspect of safe enucleation is localization of tumor at a distance of at least 2 mm from the pancreatic duct.

Diagnostic Challenges in Difficult-to-Localize Insulinomas: A Case Report and Review of Literature.

Non-somatostatin receptor expressing hypovascular insulinomas can be challenging to prove through imaging. This case highlights the utility of a structured approach to molecular imaging in patients with confirmed endogenous hyperinsulinemia. A 54-year-old woman was admitted because of a sudden loss of consciousness. Her relative reported that she complained of dizziness, intense sweating, blurry vision, and upper extremity tingling before becoming unresponsive for 20 min, after which the patient had little recollection of the event. She experienced similar episodes of shorter duration, trouble recalling everyday events, and unintentional weight gain of over 10 kg during the previous two years. Abdominal magnetic resonance imaging (MRI) and multidetector computerized tomography (MDCT) were unremarkable. Selective arterial calcium stimulation significantly increased hepatic venous insulin concentrations when the superior mesenteric and gastroduodenal arteries were stimulated. Technetium-99m (99mTc) octreotide single-photon emission computed tomography (SPECT) did not localize the lesion. Gallium-68 DOTA-Exendin-4 PET/CT acquisition was performed. A single intense 2 cm hyperperfused pancreatic lesion was located anteriorly in the head of the pancreas. Earlier targeted PET/CT imaging and recognition of significant neuropsychiatric symptoms attributable to the patient's hypoglycemic state might have accelerated the resolution of her condition and obviated the need for unnecessary testing.

A Rare Case of Malignant Insulinoma Associated With Gastrointestinal Bleed.

A gastrointestinal bleed (GIB) in the setting of metastatic insulinoma is a rare phenomenon. It appears that cases of metastatic insulinoma causing GIB are rare, often influenced by the tumor's location. Our case involves an 82-year-old male with dementia and a history of recurrent hypoglycemia, presenting with an episode of altered mental status. The patient exhibited hypoglycemia alongside a melena episode and anemia. Diagnostic criteria, including Whipple's triad, confirmed endogenous insulin production. Computed tomography (CT) showed a left paraaortic/retroperitoneal mass. Esophagogastroduodenoscopy (EGD) visualized an extrinsic mass at the gastric body, which caused an ulcerated surface that was treated with clipping and hemostasis. The patient's recurrent hypoglycemic episodes were treated with glucose, while his GIB was managed with hemostasis and clipping. However, the patient was not a surgical candidate, and further medical treatment was ceased by the family.

Spontaneous Hypoglycemia in a Non-diabetic Patient: A Diagnostic and Therapeutic Conundrum.

Hypoglycaemia is a medical emergency requiring an immediate intervention to prevent neuroglycopenic symptoms such as confusion, seizures, and coma. While evaluating for the cause of hypoglycemia, after excluding common causes like insulin use or sepsis, other causes involving endogenous hypoglycemia need to be evaluated. A cause to be considered is nesidioblastosis. This rare entity is also known as non-insulinoma pancreatogenous hypoglycemia syndrome. There have been instances where this disorder has been mistaken as insulinoma due to the characteristics shared by the two. Here, we present a case of a non-diabetic male experiencing symptoms of giddiness and palpitations for the past two years who had been extensively evaluated to rule out insulinoma and was diagnosed with nesidioblastosis.

68Ga-DOTATATE PET/CT: How is it reliable in imaging of cases having clinical suspicion of insulinomas?

PURPOSE: This retrospective study evaluates the value of 68Ga-DOTATATE PET/CT in the diagnosis and localization of insulinomas, whether sporadic, malignant or MEN-1 associated insulinoma. METHOD: The study included 43 patients, having clinical (symptomatic hypoglycemia) and/or laboratory suspicion of having insulinoma (72 h fasting test with serum insulin ≥18 pmol/L), with available pre-operative 68Ga-DOTATATE PET/CT and CE-CT, and diagnosed with insulinoma confirmed by post-operative histopathology. Preoperative imaging was retrospectively analyzed by two radiologists who were blinded to the final diagnosis and to the results of other imaging modalities. Histopathology of specimen was considered the reference standard, and head-to-head comparison of preoperative CE-CT and PET imaging findings. Findings were classified as true positive (TP), true negative (TN), false positive (FP), and false negative (FN) for each modality. Based on these results, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CE-CT, and 68Ga-DOTATATE PET/CT for the detection of insulinoma were calculated. RESULTS: 43 patients (N = 43 patients, L = 56 lesions), out of these, 37 patients had benign sporadic insulinoma (N = 37, L = 42), only 3 patients had malignant sporadic insulinoma (N = 2, L = 9), and 3 patients had MEN-1 syndrome associated insulinoma (N = 3, L = 5). There was no significant statistical difference in sensitivity (P = 0.3058) and PPV (P = 0.5533) for insulinoma localization in the overall cohort with 68Ga-DOTATATE PET/CT (87.5 %, 90.74 %) compared to CE-CT (80.36 %, 93.75 %). CONCLUSION: 68Ga-DOTATATE PET/CT is a non-invasive imaging modality that can identify most insulinomas. Still, it offers limited additional information when the tumor is localized by other anatomic imaging studies, so should be used as an adjunct when imaging studies fail to localize the tumor in insulinoma patients, especially when minimally invasive surgical is intended.

Pioneering robotic-assisted surgery for insulinoma during pregnancy: The first case report and literature review.

Introduction: Insulinoma during pregnancy is a rare condition with vague clinical symptoms, making diagnosis challenging. The standard treatment for insulinoma is surgical tumor removal, preferably using a minimally invasive method. However, there have been no recorded examples of employing a robotic platform in pregnant women with insulinoma. In this report, we present the first successful case of robotic enucleation for insulinoma during pregnancy. Case presentation: A 30-year-old pregnant woman presented with recurrent hypoglycemic symptoms throughout her first trimester that were relieved by food intake. After confirming endogenous hyperinsulinemia, an abdominal magnetic resonance imaging scan was performed to locate the tumor. A well-defined 2-cm mass was found in the pancreatic body. Robotic enucleation was performed at week 18 of gestation, and the patient experienced relief from hypoglycemic episodes postoperatively. Her blood glucose levels returned to normal, and she had an uneventful pregnancy. The patient eventually delivered a healthy baby via cesarean section without any complications. Conclusions: For a subset of pregnant individuals with insulinoma, a minimally invasive approach as robotic-assisted surgery is safe and feasible. This innovative technique has the potential to both mothers and fetuses.

A Case Report: Hypoglycaemic Unawareness Associated With Insulinoma.

Hypoglycaemic unawareness (HU) is more frequently described in relation to diabetics in the literature. We have noted that there is also an increasing reporting of HU in insulinoma cases. We report a hospital presentation for an incidental finding of hypoglycaemic unawareness in a gentleman in his fifties who was eventually diagnosed with insulinoma following biochemical studies, radiologic evaluation and histologic evaluation of an excised lesion between the pancreas and the spleen. We have reviewed existing literature evidence regarding the possible aetiologies and management options for this occurrence. More research studies to identify the epidemiology of this association and the determination of a protocol for increased detection of patients with insulinoma who display HU will need to be done.

Implications of noncoding regulatory functions in the development of insulinomas.

Insulinomas are rare neuroendocrine tumors arising from pancreatic ß cells, characterized by aberrant proliferation and altered insulin secretion, leading to glucose homeostasis failure. With the aim of uncovering the role of noncoding regulatory regions and their aberrations in the development of these tumors, we coupled epigenetic and transcriptome profiling with whole-genome sequencing. As a result, we unraveled somatic mutations associated with changes in regulatory functions. Critically, these regions impact insulin secretion, tumor development, and epigenetic modifying genes, including polycomb complex components. Chromatin remodeling is apparent in insulinoma-selective domains shared across patients, containing a specific set of regulatory sequences dominated by the SOX17 binding motif. Moreover, many of these regions are H3K27me3 repressed in ß cells, suggesting that tumoral transition involves derepression of polycomb-targeted domains. Our work provides a compendium of aberrant cis-regulatory elements affecting the function and fate of ß cells in their progression to insulinomas and a framework to identify coding and noncoding driver mutations.

Decreased islet amyloid polypeptide staining in the islets of insulinoma patients.

Islet amyloid polypeptide (IAPP) is a factor that regulates food intake and is secreted from both pancreatic islets and insulinoma cells. Here, we aimed to evaluate IAPP immunohistochemically in islets or insulinoma cells in association with clinical characteristics. We recruited six insulinoma patients and six body mass index-matched control patients with pancreatic diseases other than insulinoma whose glucose tolerance was confirmed to be normal preoperatively. IAPP and IAPP-insulin double staining were performed on pancreatic surgical specimens. We observed that the IAPP staining level and percentage of IAPP-positive beta cells tended to be lower (p = 0.1699) in the islets of insulinoma patients than in those of control patients, which might represent a novel IAPP expression pattern under persistent hyperinsulinemia and hypoglycemia.

Sweet Saboteur: Insulinoma Presenting As Recurrent Hypoglycemic Seizures.

Insulinoma, a rare neuroendocrine tumor of the pancreas, often presents diagnostic challenges due to its diverse clinical manifestations. We present the case of a 25-year-old female with recurrent hypoglycemic seizures and neuroglycopenic symptoms, ultimately diagnosed with insulinoma. Despite an initial asymptomatic period, the patient experienced progressively worsening symptoms over three years, culminating in eight episodes of generalized tonic-clonic seizures per week. Biochemical investigations during hypoglycemic episodes revealed elevated C-peptide and insulin levels, consistent with endogenous hyperinsulinemia. Imaging studies, including contrast-enhanced computed tomography (CECT) and Ga-DOTATATE scan, confirmed a hyper-enhancing lesion in the distal body of the pancreas, indicative of insulinoma. Histopathological examination (HPE) further corroborated the diagnosis. Prompt recognition and surgical excision led to the complete resolution of symptoms and improved long-term prognosis. This case underscores the importance of considering insulinoma in young individuals presenting with recurrent hypoglycemic episodes and highlights the significance of early diagnosis and intervention in preventing morbidity and mortality associated with this condition.

Clinicopathological Features of Pediatric Insulinoma: A Single-Centre Study.

Aims/Background: Insulinoma is an extremely rare condition in pediatric patients. This study aims to examine the pathological and clinical characteristics of pediatric insulinoma. Methods: A retrospective, single-center study was conducted involving five pediatric patients diagnosed with insulinoma. The study involved evaluating the postoperative status of the patients during follow-up and analyzing their clinical manifestations, diagnostic work-up, pathological findings, and therapeutic approaches. Results: The study cohort comprised four males and one female, aged between 4 and 9 years. Common symptoms included dizziness and fatigue. The insulinomas were located in various parts of the pancreas: two in the head, one in the neck, one in the body, and one in the tail. After undergoing subtotal pancreatectomy, four patients experienced no side effects during a follow-up period of 41 to 153 months. One patient, who underwent an incomplete pancreatic resection, required ongoing postoperative treatment with 150 mg Creon due to pancreatic enzyme deficiency. Postoperative pathological results indicated that all cases were low-grade neuroendocrine tumours, classified as grade 1 (G1) or grade 2 (G2). Two cases exhibited capsule invasion, and one case showed microvascular invasion. Despite these invasions, no recurrences or metastases have been observed to date. Conclusion: Surgical resection is a viable treatment option for pediatric insulinoma, yielding a favorable prognosis. The presence of capsular and microvascular invasions does not seem to affect the overall prognosis in these cases.

Pancreatic Insulinoma Masquerading as Neurological Disease: Diagnosis and Treatment of a Rare Tumor.

Insulinomas are rare functional pancreatic neuroendocrine tumors that typically manifest with classic hypoglycemic symptoms, such as diaphoresis, palpitations, and tremors. Although infrequent, neuroglycopenic symptoms associated with insulinomas have been reported, often leading to delayed diagnoses. Here, we present the case of a 31-year-old male with pancreatic insulinoma who experienced recurrent episodes of seizures and confusion preceded by diaphoresis, tremors, and palpitations. During these episodes, he was found to be hypoglycemic. Comprehensive evaluations, including brain and abdominal imaging, as well as biochemical and serological testing, were conducted. The findings confirmed a diagnosis of pancreatic insulinoma. The patient underwent surgical resection of the tumor, and a biopsy confirmed the insulinoma diagnosis. He remained asymptomatic during subsequent follow-ups.

Stereotactic Body Radiation Therapy for Symptomatic Pancreatic Insulinoma: Two-Case Report and Literature Review.

Insulinoma is the most common functional neuroendocrine tumor of the pancreas, with the main clinical symptom being hypoglycemia. The standard treatment is surgery, but some patients are not eligible for surgery, while in those operated on, the risk of perioperative complications is up to 30%. Diazoxide treatment to prevent hypoglycemia is effective only in 50% of patients. To prevent tumor growth and hormonal excess, stereotactic radiotherapy may be an alternative to surgical treatment. In our paper, we present two cases of patients with insulinoma treated successfully with stereotactic body radiation therapy (SBRT).

Repair Effect of Umbilical Cord Mesenchymal Stem Cells Embedded in Hydrogel on Mouse Insulinoma 6 Cells Injured by Streptozotocin.

Umbilical cord mesenchymal stem cells (UC-MSCs) possess the capabilities of differentiation and immune modulation, which endow them with therapeutic potential in the treatment of type 2 diabetes mellitus (T2DM). In this study, to investigate the repair mechanism of UC-MSCs in hydrogel on pancreatic ß-cells in diabetes, mouse insulinoma 6 (MIN-6) cells damaged by streptozotocin (STZ) in vitro were used in co-culture with UC-MSCs in hydrogel (UC-MSCs + hydrogel). It was found that UC-MSCs + hydrogel had a significant repair effect on injured MIN-6 cells, which was better than the use of UC-MSCs alone (without hydrogel). After repair, the expression of superoxide dismutase (SOD) and catalase (CAT) as well as the total antioxidant capacity (T-AOC) of the repaired MIN-6 cells were increased, effectively reducing the oxidative stress caused by STZ. In addition, UC-MSCs + hydrogel were able to curb the inflammatory response by promoting the expression of anti-inflammatory factor IL-10 and reducing inflammatory factor IL-1ß. In addition, the expression of both nuclear antigen Ki67 for cell proliferation and insulin-related genes such as Pdx1 and MafA was increased in the repaired MIN-6 cells by UC-MSCs + hydrogel, suggesting that the repair effect promotes the proliferation of the injured MIN-6 cells. Compared with the use of UC-MSCs alone, UC-MSCs + hydrogel exhibit superior antioxidant stress resistance against injured MIN-6 cells, better proliferation effects and a longer survival time of UC-MSCs because the porous structure and hydrophilic properties of the hydrogel could affect the growth of cells and slow down their metabolic activities, resulting in a better repair effect on the injured MIN-6 cells.

Super paramagnetic iron oxide contrast-enhanced magnetic resonance imaging was useful in differentiating an insulinoma from an accessory spleen: a case report with review of literature.

When a neuroendocrine tumor with abundant blood flow is located in the pancreatic tail, it is difficult to distinguish it from accessory spleen. The patient was a 71-year-old woman who was admitted with impaired consciousness and hypoglycemia, raising suspicion of insulinoma. The selective arterial calcium injection test suggested a lesion in the pancreatic tail. Contrast-enhanced computed tomography and magnetic resonance imaging (MRI) showed a mass in the splenic hilum; however, its continuity with the pancreas was unclear. Contrast-enhanced MRI using super paramagnetic iron oxide (SPIO) showed no SPIO uptake in the splenic hilar mass. SPIO contrast-enhanced MRI is considered useful for differentiating pancreatic endocrine tumors from paraspleen tumors.

Insulinoma Unmasked Post Sleeve Gastrectomy With Incidental Renal Cell Carcinoma: A Rare Case.

Insulinoma is a functional pancreatic neuroendocrine tumor (pNET). Usually benign and solitary, these tumors present with recurrent episodes of hypoglycemia due to insulin hypersecretion. It's a rare cause of post bariatric surgery hypoglycemia and hence poses a diagnostic challenge. Here, we report the first case of a 53-year-old male with insulinoma unmasked post sleeve gastrectomy with incidental renal cell carcinoma (RCC). He presented with symptoms of Whipple's triad after two months of sleeve gastrectomy done for morbid obesity. On further inquiry, the patient gave a history of an asymptomatic peripancreatic neuroendocrine tumor (NET) for the past 11 years. With a suspicion of insulinoma, biochemical workup followed by non-invasive imaging like GA-68 DOTA and CT triphasic abdomen scan was done to guide the diagnosis of an insulinoma which also detected a second primary tumor in the right kidney, likely to be a malignant RCC. Following pancreatic mass excision with radical nephrectomy for right renal mass, histopathology (HPE) and immunohistochemistry (IHC) confirmed the diagnosis of an insulinoma and a right renal clear cell carcinoma. The patient was discharged with no further episodes of hypoglycemia. Hence, persistent hypoglycemia post bariatric surgery could be an indication of a hidden insulinoma and this possibility of synchronous tumors should be kept in mind when dealing with rare tumors like insulinoma.