A Case of Glucose-Responsive Insulinoma Presenting with Reactive Hypoglycemia
Year: 1994
Type: article
Study design: Case Report
Abstract: A 56-year-old man was admitted for evaluation of progressive postprandial hypoglycemia over a ten-year period. The high concentration of fasting plasma immunoreactive insulin (80μ/ml with 34 mg/d l of plasma glucose (PG), even though without hypoglycemic symptoms, suggested the presence of insulinoma. Excessive insulin secretion was also observed after meals (2h after breakfast: insulin 307μU/ml, PG 118mg/dl). Oral and intravenous glucose tolerance tests and the glucagon test resulted in excessive insulin secretion with peaks of 1040μU/ml, >9999μU/mland 2768 μU/ml, respectively. PG concentrations during intravenous glucose tolerance and glucagon tests decreased to less than 30 mg/dl. A fasting exercise test performed suppressed insulin secretion from 31 μU/ml to 6 μU/mlat 60 min and fasting raised PG from 48 mg/dlto 82 mg/dl. A 2 cm tumor in the head of the pancreas was removed and identified histologically as a benign insulin-secreting islet cell tumor. In summary, we report a rare case of insulinoma characterized by excessive insulin secretion in response to glucose, and therefore, postprandial hypoglycemia.
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7145911892