Hyperinsulinemic hypoglycemia due to adult nesidioblastosis in insulin-dependent diabetes

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.

NESIDIOBLASTOSIS IN AN ADULT WITH SHORT GUT SYNDROME AND TYPE 2 DIABETES

OBJECTIVE

Adult nesidioblastosis is characterized by endogenous hyperinsulinemia typically causing post-prandial hypoglycemia, and most commonly occurs post-Roux-en-Y gastric bypass.

METHODS

We report a unique case of nesidioblastosis occurring in a 67-year-old female.

RESULTS

A 5-year history of symptomatic hypoglycemia occurred in a patient with short bowel syndrome and type 2 diabetes mellitus (T2DM) managed previously with a glucagon-like peptide 1 (GLP-1) agonist, which achieved significant weight loss. Continuous glucose monitoring captured 42 hypoglycemia episodes in a 2-week period, and following an oral glucose tolerance test there was the suggestion of a hyperinsulinemia state. She was managed with an open distal pancreatectomy, and subsequently required medical therapy to maintain euglycemia.

CONCLUSION

We present the first case of nesidioblastosis occurring in a patient with short bowel syndrome, pre-existing T2DM managed with a GLP-1 agonist which achieved significant weight loss, all of which we speculate could have predisposed to hypoglycemia and development of nesidioblastosis.

[Nesidioblastosis in the adult: a case report]

BACKGROUND

Nesidioblastosis is a rare cause of endocrine disease which represents between 0.5% - 5% of cases. This has been associated with other conditions, such as in patients previously treated with insulin or sulfonylurea, in anti-tumour activity in pancreatic tissue of patients with insulinoma, and in patients with other tumours of the Langerhans islet cells. In adults it is presented as a diffuse dysfunction of β cells of unknown cause.

CLINICAL CASE

The case concerns 46 year-old female, with a history of Sheehan syndrome of fifteen years of onset, and with repeated events characterized with hypoglycaemia in the last three years. Body scan was performed with octreotide, revealing an insulinoma in the pancreatic region. A distal pancreatectomy was performed on the patient. The study reported a pancreatic fragment 8.5 × 3 × 1.5 cm with abnormal proliferation of pancreatic islets in groups of varying size, some of them in relation to the ductal epithelium. Histopathology study was showed positive for chromogranin, confirmed by positive synaptophysin, insulin and glucagon, revealing islet hyperplasia with diffuse nesidioblastosis with negative malignancy. The patient is currently under metabolic control and with no remission of hypoglycaemic events.

CONCLUSIONS

Nesidioblastosis is a disease of difficult diagnosis should be considered in all cases of failure to locate an insulinoma, as this may be presented in up to 4% of persistent hyperinsulinaemic hypoglycaemia.

[Nesidioblastosis (diagnosis, surgical treatment)]

INTRODUCTION

Nesidioblastosis (NB) is rare disease with organic hyperinsulinism syndrome and caused by diffuse hyperplasia and/or hypertrophy of pancreatic islands of Langerhans.

MATERIAL AND METHODS

The results of surgical treatment of 3 patients with NB are presented. In all patients the diagnosis was suspected at the preoperative stage and confirmed by histological examination later. Herewith in 2 patients NB was combined with insulinoma. All patients underwent corpora-caudal pancreatectomy.

RESULTS

In postoperative period one patient hadn't episodes of hypoglycemia for the entire follow-up period (5 months), in another patient hypoglycemic states occurred at 1.5 months after surgery. The third patient required pancreatic head extirpation at 11 days after surgery due to persistent severe course of organic hyperinsulinism. In immediate postoperative period in the same patient hyperinsular hypoglycemia was observed that pointed on extrapancreatic source of insulin secretion. However contrast-enhanced CT did not reveal any formations.

CONCLUSION

Thus, corpora-caudal pancreatectomy is preferable as surgical treatment. Results of surgical management can provide a complete regression of the symptoms, but do not guarantee absence of recurrence and even any changes in frequency and severity of hypoglycemic states.

An unusual cause of hypoglycemia in a middle-aged female after bariatric surgery

Non-insulinoma pancreatogenous hypoglycemia syndrome (NIPHS) is a disorder characterized by postprandial hypoglycemia and islet cell hypertrophy. It is an uncommon complication of weight-loss surgery. However, with the rising incidence of gastric bypass surgeries, it is important to be able to recognize the clinical picture of NIPHS and not to incorrectly ascribe the symptoms to late dumping syndrome.

GLP-1 and glucagon secretion from a pancreatic neuroendocrine tumor causing diabetes and hyperinsulinemic hypoglycemia

CONTEXT

Glucagon-like peptide-1 (GLP-1) is a gut peptide that promotes insulin release from pancreatic β-cells and stimulates β-cell hyperplasia. GLP-1 secretion causing hypoglycemia has been described once from an ovarian neuroendocrine tumor (NET) but has not been reported from a pancreatic NET (pNET).

OBJECTIVE

A 56-yr-old male with a previous diagnosis of diabetes presented with fasting hypoglycemia and was found to have a metastatic pNET secreting glucagon. Neither the primary tumor nor metastases stained for insulin, whereas the resected normal pancreas showed histological evidence of islet cell hyperplasia. We provide evidence that GLP-1 secretion from the tumor was the cause of hyperinsulinemic hypoglycemia.

METHODS

GLP-1 levels were determined in the patient, and immunohistochemistry for GLP-1 was performed on the tumor metastases. Ex vivo tissue culture and a bioassay constructed by transplantation of tumor into nude mice were performed to examine the tumor secretory products and their effects on islet cell function.

RESULTS

The patient had high levels of glucagon and GLP-1 with an exaggerated GLP-1 response to oral glucose. Immunohistochemistry and primary tissue culture demonstrated secretion of glucagon and GLP-1 from the tumor metastases, whereas insulin secretion was almost undetectable. Ex vivo coculture of the tumor with normal human islets resulted in inhibition of insulin release, and transplanted mice developed impaired glucose tolerance.

CONCLUSIONS

This is the first description of glucagon and GLP-1 secretion from a metastatic pNET causing sequential diabetes and hypoglycemia. Hypoglycemia was caused by insulin secretion from hyperplastic β-cells stimulated by tumor-derived GLP-1.

Occult sporadic insulinoma: Localization and surgical strategy

Insulinomas continue to pose a diagnostic challenge to physicians, surgeons and radiologists alike. Most are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained and imaging techniques to localize lesions continue to evolve. Surgical resection is the treatment of choice. Despite all efforts, an occult insulinoma (occult insulinoma refers to a biochemically proven tumor with indeterminate anatomical site before operation) may still be encountered. New localization preoperative techniques decreases occult cases and the knowledge of the site of the mass before surgery allows to determine whether enucleation of the tumor or pancreatic resection is likely to be required and whether the tumor is amenable to removal via a laparoscopic approach. In absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.