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Insulinoma presenting as hypoglycemia during lactose tolerance testing: a case report
Vicki Munro1, Laura M McDonell2, Valerie Keough3
1Division of Endocrinology and Metabolism, Department of Medicine, Dalhousie University, Halifax, NS, Canada.
Journal of Medical Case Reports
|July 2, 2020
Summary
Insulinoma, a rare pancreatic tumor causing hypoglycemia, can present subtly. This case highlights its detection during lactose tolerance testing, leading to successful treatment and symptom resolution.
Area of Science:
- Endocrinology
- Oncology
- Gastroenterology
Background:
- Insulinoma is a rare, sporadic pancreatic endocrine tumor causing hypoglycemia.
- Symptoms include autonomic and neuroglycopenic manifestations, often leading to diagnostic delays.
Observation:
- A 60-year-old man presented with confusion and hypoglycemia during lactose tolerance testing.
- He had an 8-year history of subtle neuroglycopenic symptoms.
- Biochemical tests and imaging confirmed a 1.2-cm pancreatic tail insulinoma.
Findings:
- Laparoscopic resection of the insulinoma resulted in complete symptom resolution.
- The patient maintained normal glucose levels post-surgery.
- This is the first reported case of insulinoma detected via hypoglycemia during lactose tolerance testing.
Implications:
- Clinicians should consider insulinoma in patients with symptomatic hypoglycemia.
- Subtle and nonspecific presentations necessitate vigilance for functioning pancreatic neuroendocrine tumors.
- Lactose tolerance testing may reveal unexpected hypoglycemia indicative of insulinoma.
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