Functional Localization of Adult-Onset Idiopathic Nesidioblastosis

Area of Science:

• Endocrinology
• Gastroenterology
• Pathology

Background:

• Nesidioblastosis is a rare pancreatic disorder characterized by enlarged islet cells and hyperinsulinism.
• Fasting hypoglycemia is a primary symptom, often necessitating advanced diagnostic imaging and testing.

Observation:

• A 53-year-old woman presented with fasting hypoglycemia.
• Standard imaging (CT, MRI) and octreotide scans were negative for insulinoma.
• Selective arterial calcium stimulation (SACST) indicated focal areas of hyperinsulinism within the pancreas.

Findings:

• SACST identified increased insulin production from specific arterial territories, suggesting localized nesidioblastosis.
• Histopathology post-subtotal distal pancreatectomy confirmed nesidioblastosis.
• The patient achieved normal glucose tolerance and resolution of hypoglycemia after surgery.

Implications:

• This case highlights SACST as a valuable tool for diagnosing localized nesidioblastosis when conventional methods fail.
• The successful surgical outcome demonstrates the efficacy of targeted pancreatectomy for partial nesidioblastosis.
• Understanding the localized nature of nesidioblastosis is crucial for accurate diagnosis and effective treatment strategies.