Synchronous Nesidioblastosis, Endocrine Microadenoma, and Intraductal Papillary Mucinous Neoplasia in a Man Presenting With Hyperinsulinemic Hypoglycemia

Noninsulinoma Pancreatogenous Hypoglycemia Syndrome in a Patient With 1p36 Deletion Syndrome

The 1p36 deletion syndrome involves a phenotypic presentation that includes central nervous system, cardiac, and craniofacial anomalies. We report the case of a 21-year-old female patient with 1p36 deletion syndrome who was found to have noninsulinoma pancreatogenous hypoglycemia syndrome (NIPHS) after hospitalization for persistent falls. On admission, vital signs were normal and physical examination revealed a thin, nonverbal patient. During hospitalization and prolonged fasting (14-18 hours), she persistently developed hypoglycemia (serum glucose nadir 57 mg/dL [3.2 mmol/L] [70-100 mg/dL; 3.9-5.6 mmol/L]). Subjective symptoms of hypoglycemia were not confirmed due to patient's cognitive impairment. Hypoglycemic events continued despite feeding and dextrose-containing fluids. Further workup included a critical sample that revealed a serum glucose 59 mg/dL (3.3 mmol/L), insulin 20.6 μIU/mL (123.6 pmol/L [5-15 μIU/mL; 30.0-90 pmol/L]), proinsulin 33 pmol/L (3.6-22 pmol/L), C-peptide 1.74 ng/mL (0.58 nmol/L [0.8-3.85 ng/mL; 0.27-1.28 nmol/L]) and beta-hydroxybutyrate < 1.04 mg/dL (< 0.10 mmol/L; [< 4.2 mg/dL; < 0.4 mmol/L]). Insulin antibodies were negative. After confirmed insulin-mediated hypoglycemia, imaging studies followed. Pancreatic protocol abdominal computed tomography (CT), Ga-68 DOTATATE PET/CT scan, and endoscopic ultrasound found no pancreatic mass. Selective arterial calcium stimulation test showed a two-fold increase in insulin levels in 3/3 catheterized pancreatic territories. The patient started octreotide injections with resolution of hypoglycemia and was discharged on monthly lanreotide injections. To our knowledge, this is the first case reported of noninsulinoma pancreatogenous hypoglycemia in a patient with 1p36 deletion syndrome.

An Uncommon Cause of Recurrent Presyncope, Dizziness, and Tachycardia: A Case Report of Diffuse, Adult-Onset Nesidioblastosis/Non-Insulinoma Pancreatogenous Hypoglycemia Syndrome (NIPHS)

Neurovegetative and autonomic symptoms are common presentations of various diseases, ranging from psychosomatic to severe organic disorders. A 23-year-old man presented with a history of recurrent presyncope, dizziness, and tachycardia. Repeated diagnostic work-up in various clinical settings could not identify any definite cause for approximately eight years. However, the incidental detection of postprandial and exercise-induced hypoglycemia was suggestive of an insulin-related disorder. A 72 h plasma glucose fasting test revealed endogenous hyperinsulinism. Upon imaging studies, no tumor mass potentially indicating insulinoma could be detected. ⁶⁸Ga-DOTA-Exendin-4 PET/CT showed diffuse tracer enrichment throughout the whole pancreas. A subtotal pancreatectomy was performed, and the diagnosis of diffuse, adult-onset nesidioblastosis was established histopathologically. This corresponds to the clinical findings of a functional β-cell disorder, also known as non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS). After nine months, the symptoms recurred, making complete pancreatectomy necessary. Postoperative laboratory evaluation exhibited no residual endogenous C-peptide production. This case illustrates the diagnostic challenges in patients presenting with unspecific, neurovegetative and autonomic symptoms with a severe and rare underlying cause.

Diffuse, Adult-Onset Nesidioblastosis/Non-Insulinoma Pancreatogenous Hypoglycemia Syndrome (NIPHS): Review of the Literature of a Rare Cause of Hyperinsulinemic Hypoglycemia

Differential diagnosis of hypoglycemia in the non-diabetic adult patient is complex and comprises various diseases, including endogenous hyperinsulinism caused by functional β-cell disorders. The latter is also designated as nesidioblastosis or non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS). Clinically, this rare disease presents with unspecific adrenergic and neuroglycopenic symptoms and is, therefore, often overlooked. A combination of careful clinical assessment, oral glucose tolerance testing, 72 h fasting, sectional and functional imaging, and invasive insulin measurements can lead to the correct diagnosis. Due to a lack of a pathophysiological understanding of the condition, conservative treatment options are limited and mostly ineffective. Therefore, nearly all patients currently undergo surgical resection of parts or the entire pancreas. Consequently, apart from faster diagnosis, more elaborate and less invasive treatment options are needed to relieve the patients from the dangerous and devastating symptoms. Based on a case of a 23-year-old man presenting with this disease in our department, we performed an extensive review of the medical literature dealing with this condition and herein presented a comprehensive discussion of this interesting disease, including all aspects from epidemiology to therapy.

Complete remission of recurrent multiple insulin-producing neuroendocrine tumors of the pancreas with somatostatin analogs: a case report and literature review

Hyperinsulinemic hypoglycemia is most commonly caused by a single, sporadic insulinoma. Multicentric insulinoma disease (insulinomatosis) as well as metachronous neuroendocrine tumors of the pancreas, known also as neuroendocrine adenomatosis, represent a very rare condition, if not associated with multiple endocrine neoplasia type 1 syndrome (MEN1) or Von Hippel Lindau disease. We report a 9-year follow-up of a 41-year-old woman, initially presenting with hypoglycemic syndrome caused by two insulin-producing tumors, who underwent subtotal pancreasectomy in 2012, with histology compatible with multiple small neuroendocrine tumors. An approximately 1-cm insulin-producing tumor recurred at subsequent biochemical and radiological follow-up, and was cured with the somatostatin analog octreotide as a single treatment, until remission of symptoms and complete regression of the pancreatic lesion achieved after only 16 months of treatment. The possible mechanisms for these findings are discussed and the literature is briefly reviewed.

Nesidioblastosis Associated with Pancreatic Heterotopia as a Differential Diagnosis of Hypoglycemia: A Literature Review and Case Report

Patient: Male, 32-year-old

Final Diagnosis: Nesidioblastosis

Symptoms: Hypoglycemia

Medication:—

Clinical Procedure: Distal pancreatectomy • magnetic resonance image • selective arterial calcium stimulation test with hepatic venous sampling

Specialty: Endocrinology and Metabolic

Nesidioblastosis and Insulinoma: A Rare Coexistence and a Therapeutic Challenge

Background: Nesidioblastosis and insulinoma are disorders of the endocrine pancreas causing endogenous hyperinsulinemic hypoglycemia. Their coexistence is very unusual and treatment represents a still unresolved dilemma. Case Description: The patient was a 43-year-old Caucasian woman, with a 2-year history of repeated severe hypoglycemic events. The diagnostic work-up was strongly suggestive of insulinoma and the patient was submitted to surgical treatment carried out laparoscopically under robotic assistance. However, surgical exploration and intraoperative ultrasonography failed to detect a pancreatic tumor. Resection was therefore carried out based on the results of selective intra-arterial calcium stimulation test, following a step-up approach, eventually leading to a pancreatoduodenectomy at the splenic artery. The histopathology examination and the immunohistochemical staining were consistent with adult-onset nesidioblastosis. After surgery, the patient continued to experience hypoglycemia with futile response to medical treatments (octreotide, calcium antagonists, diazoxide, and prednisone). Following multidisciplinary evaluation and critical review of a repeat abdominal computed tomography scan, a small nodular lesion was identified in the tail of the pancreas. The nodule was enucleated laparoscopically and the pathological examination revealed an insulinoma. In spite of the insulinoma resection, glycemic values were only partially restored, with residual nocturnal hypoglycemia. Administration of uncooked cornstarch (1.25 g/kg body weight) at bedtime was associated with significant improvement of interstitial glucose levels (p < 0.0001) and reduction of nocturnal hypoglycemia episodes (p = 0.0002). Conclusions: This report describes a rare coexistence of adult-onset nesidioblastosis and insulinoma, suggesting the existence of a wide and continuous spectrum of proliferative β-cell changes. Moreover, we propose that uncooked cornstarch may offer an additional approach to alleviate the hypoglycemic episodes when surgery is impracticable/unaccepted.

Concurrent Adult-Onset Diffuse β-Cell Nesidioblastosis and Pancreatic Neuroendocrine Tumor: A Case Report and Review of the Literature

Nesidioblastosis is an uncommon cause of organic persistent hyperinsulinemic hypoglycemia in adults. We report a case of adult-onset diffuse β-cell nesidioblastosis in a 49-year-old woman who was status-post Roux-en-Y gastric bypass and distal pancreatectomy for a well-differentiated pancreatic neuroendocrine tumor. While the neuroendocrine tumor was suspected to be an insulinoma, persistent hypoglycemia postoperatively suggested either incomplete resection or a second pancreatic neoplasm. Completion pancreatectomy revealed islet β-cell hyperplasia and nuclear pleomorphism consistent with β-cell nesidioblastosis. The patient's blood glucose levels normalized after completion pancreatectomy. While β-cell nesidioblastosis and insulinomas can coexist in the same patient, pathologists should be aware of β-cell nesidioblastosis as a potential cause for hyperinsulinemic hypoglycemia and should exclude it in patients who have not shown definitive clinical response after surgical excision of a pancreatic neuroendocrine tumor.

Pancreatic Neuroendocrine Tumors and Intraductal Papillary Mucinous Neoplasm of the Pancreas: A Systematic Review

OBJECTIVES

This study aimed to identify factors that explain the association of intraductal papillary mucinous neoplasms-pancreatic neuroendocrine tumors (IPMNs-PNETs), radiological characteristics, and factors that might guide therapy.

METHODS

We performed a systematic review of the literature to search for articles on concurrent IPMN-PNET, mixed endocrine-exocrine pancreatic tumors, and/or PNET with an intraductal growth pattern.

RESULTS

A review of the literature suggests that there is some confusion about association of IPMNs-PNETs. Regarding this association, the studies collected data from 32 patients. Eleven patients presented concurrent tumors, 9 mixed endocrine-exocrine tumors, and no data were available in the remaining 7. In addition, the relationship IPMN-PNET focuses not only on the coexistence of the 2 lesions, but also on the possibility of the intraductal growth of the endocrine lesion. In the literature, in 4 cases, the preoperative radiological diagnosis had been IPMN.

CONCLUSIONS

Intraductal papillary mucinous neoplasms and PNETs may be associated in a number of scenarios. The association may be due to the concurrent existence of independent lesions, may be a mixed endocrine-exocrine tumor, or may be due to intraductal growth of the endocrine lesion. But the literature is confusing. It is not known whether the association is accidental or whether there is an etiological reason. Further studies are needed to investigate this scenario.

Intraductal papillary mucinous neoplasm of the pancreas associated with neuroendocrine tumor: A case report

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The panreatic IPMN and neuroendocrine carcinoma is very unusual.

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The IPMN component of our patient has high grade dysplasia, which is very rare.

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In presence of contrast enhancing nodular foci, while evaluating IPMN on imaging studies, possibilty of neuroendocrine tumor should be in mind.

Introduction

Intraductal papillary mucinous neoplasm is an uncommon cystic tumor of pancreas that can be associated with ductal adenocarcinoma. Coexistence of pancreatic IPMN and neuroendocrine tumor is very rare. Here, we report the imaging features of mixed type intraductal papillary mucinous neoplasia of the pancreas with high grade dysplasia together with neuroendocrine carcinoma and perform review of the literature.

Presentation

A 68-year old patient has been evaluated for possible IPMN that was suspected during ultrasound. MRI revealed main and side branch duct dilatations. At the head, a contrast enhancing nodular lesion was identified. Due to the presence of high risk stigmata according to guidelines, surgery was performed. Histopathological examination revealed an unusual association, including mixed type IPMN and neuroendocrine carcinoma.

Discussion

The concomitant occurrence of pancreatic IPMN and neuroendocrine tumor has been reported in case studies and brief reviews. Yet, the imaging findings and underlying molecular mechanisms of this entity has not been fully understood. In addition to this unusual association, pancreatic intraepithelial neoplasia was also detected in the present case. Although majority of neuroendocrine tumor associated IPMNs were reported to be having low grade dysplasia, our patient had high grade dysplasia. Further studies and reviews with larger groups are needed to establish imaging features and underlying molecular mechanisms of this rare association.

Conclusion

Although the major concern during work-up of IPMN is presence of associated pancreatic ductal adenocarcinoma, the possibility of neuroendocrine tumor, in the presence of a hypervascular solid foci on imaging studies should be kept in mind.

Insulinoma Due to Multiple Pancreatic Microadenoma Localized by Multimodal Imaging

CONTEXT

Insulinomas are usually due to a solitary tumor, but they can be challenging to localize.

CASE DESCRIPTION

A 66-year-old woman presented with a 1-year history of episodic neuroglycopenic hypoglycemia and was suspected of having an insulinoma. On a supervised fast, she was found to be hypoglycemic at 39 mg/dL, with an insulin of 40 μU/mL 26 hours into the fast and a proinsulin of 35 pmol/L. Contrast-enhanced computed tomography and magnetic resonance imaging did not localize a pancreatic lesion. Intra-arterial calcium stimulation testing showed a step-up of venous insulin levels at injection of the superior mesenteric artery and proximal and mid-splenic artery, and a ⁶⁸Ga-DOTATATE positron emission tomography/computed tomography showed focal uptake in the neck of the pancreas with a standardized uptake value of 12. Despite negative intraoperative pancreatic palpation and ultrasound, the patient underwent an extended distal pancreatectomy with normalization of biochemical levels and resolution of her symptoms. Pathology showed four subcentimeter neuroendocrine tumors that were positive for insulin, consistent with a diagnosis of multiple microadenomas.

CONCLUSIONS

Multiple microadenomas are a rare cause of hyperinsulinemic hypoglycemia and localization, and resection of these tumors may be facilitated by multimodal imaging.