Nesidioblastosis associated with insulin-mediated hypoglycemia in an adult

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.

A Case Report of Insulinoma Relapse on Background Nesidioblastosis: A Rare Cause of Adult Hypoglycemia

CONTEXT

Nesidioblastosis is a rare cause of adult hypoglycemia. Current medical therapy can mitigate disease symptoms. However, side effects and limited efficacy may prevent long-term disease management.

CASE DESCRIPTION

A 63-year-old white woman presented at our institution on April 2017 with a history of distal spleno-pancreatectomy for well-differentiated insulinoma in 2013. Hypoglycemic events did not resolve after surgery, and residual nesidioblastosis near the pancreatic resection margins was identified. Hypoglycemic episodes increased in frequency and severity despite high-dose diazoxide (DZX) therapy. On April 2016, octreotide was introduced but soon discontinued for inefficacy. When the patient arrived at our attention, add-on pasireotide was started and glucose levels monitored by subcutaneous sensor. Compared with DZX, 225 mg/d alone, sensor glucose during pasireotide + DZX 75 mg/d showed occurrence of severe hypoglycemia. Pasireotide was discontinued, and the instrumental workup (68Ga-DOTATOC CT/positron emission tomography, 99mTc-nanocolloid scintigraphy and echo-endoscopy + fine-needle aspiration biopsy) identified an insulinoma relapse. Subtotal pancreatectomy was performed without further recurrence of hypoglycemia over 9 months of follow-up.

CONCLUSIONS

Although insulinoma relapses on background nesidioblastosis rarely occur, they should be considered as an alternate diagnosis when medical therapy fails to prevent hypoglycemia. Further studies are warranted to test whether the immunophenotypic signature of nesidioblastosis/insulinoma may provide insights for a tailored use of pasireotide.

Nesidioblastosis associated with hyperinsulinemic hypoglycemia in adults: review of the literature

Nesidioblastosis is a term that was first introduced by Laidlaw in 1938 to define the diffuse proliferation of pancreatic islet cells budding from ductal epithelium. First described in neonates, it is widely recognized to be the primary cause of persistent hyperinsulinemic hypoglycemia in infants. In adults, insulinoma accounts for most cases of hyperinsulinemic hypoglycemia. Adult-onset nesidioblastosis associated with hyperinsulinemic hypoglycemia is a very rare entity, representing 0.5-5% of cases of organic hyperinsulinemia. Since 1981, when Harness et al. reported the first series of adult nesidioblastosis causing hypoglycemia, only 71 cases have been published. This article provides a guide for the diagnosis of organic hyperinsulinism and indicates when nesidioblastosis should be suspected. New diagnostic methods and treatment options for this rare disease are proposed. We also present a review of all reported cases of adult nesidioblastosis in the last 22 years.

Noninsulinoma pancreatogenous hypoglycemia syndrome: an update in 10 surgically treated patients

BACKGROUND

Neuroglycopenia from endogenous hyperinsulinism usually is caused by insulinomas in adults. We recently reported a novel hypoglycemic disorder in 5 patients (patients 1 to 5) with postprandial neuroglycopenia, negative 72-hour fasts, negative perioperative imaging studies, but positive calcium stimulation tests and islet hypertrophy and nesidioblastosis in the gradient-guided resected pancreata.

METHODS

In this report we compare our experience with 5 additional patients (patients 6 to 10) with this syndrome to that in the original report.

RESULTS

The clinical features of patients 6 to 10 were similar to those of patients 1 to 5. Each had positive calcium stimulation testing that guided the extent of the distal pancreatectomy and histologic evidence of islet cell hypertrophy or nesidioblastosis. All 10 patients are alive from 9 to 50 months after operation, 1 of whom had no amelioration of neuroglycopenia. Minor perioperative complications occurred in 3 patients. One patient has experienced repeated bouts of acute pancreatitis, pseudocyst formation, and exocrine insufficiency.

CONCLUSIONS

We have identified adult patients with severe, postprandial hyperinsulinemic hypoglycemia from diffuse islet cell disease, 80% of whom have been well palliated with surgery. The results in 7 men have been better than those in the 3 women for reasons that are not obvious.

Familial hyperinsulinism with apparent autosomal dominant inheritance: clinical and genetic differences from the autosomal recessive variant

We describe three families with hypoglycemia caused by familial hyperinsulinism (HI) in whom vertical transmission of the disorder occurred, suggesting autosomal dominant (AD) inheritance. We therefore examined the relationship between the apparent AD disorder and the more common autosomal recessive (AR) form of HI, which has recently been linked to the sulfonylurea receptor on chromosome 11p15.1. The clinical features of the 11 patients with AD HI were milder than those seen in 14 patients with AR HI. Hypoglycemia was readily controlled with either diet alone or with diazoxide in 10 of 11 patients with AD HI but in none of those with the AR form. In one large pedigree, analysis of genomic DNA with polymorphic simple sequence repeat markers excluded linkage of AD HI to the SUR locus in a dominant manner. The possibility of linkage to the SUR locus could not be absolutely excluded in the two smaller pedigrees. None of the published mutations of the SUR gene identified in patients with AR HI were detected in the patients with the AD form. We conclude that the AD form of hyperinsulinism is phenotypically different from the AR variant. The identification of more families with this form of HI may make it possible to locate the responsible gene by the use of linkage analysis.

Hyperinsulinaemic hypoglycaemia due to chlorpropamide-induced nesidioblastosis

A 25 year old woman suffering from recurrent attacks of hypoglycaemia underwent a laparotomy for suspected insulinoma. No tumour was found, but histology showed islet cell hyperplasia and nesidioblastosis. Although these changes have been reported as a cause of hypoglycaemia in infants, they are only rarely the cause of hypoglycaemia in adults; in the present case they were found to be the result of covert sulphonylurea administration. The fact that sulphonylureas can cause nesidioblastosis is not well recognised by either physicians or pathologists and it should be considered before "cryptogenic nesidioblastosis" is deemed the cause of hypoglycaemia in adults.