Concurrent insulinoma and impaired glucose tolerance suspected as owing to obesity

Katsumi Iizuka, Taro Fujisawa, Jun Takeda

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2 Citations (Scopus)


An obese 68-year-old woman was admitted for examination of fasting hypoglycaemia. A prolonged 18 h fast reduced her plasma glucose without suppressing insulin secretion, while plasma β-hydroxybutyrate levels were suppressed. Despite the prolonged fast, the glucose response to glucagon was increased by 25 mg/dL (1.39 mM) glucose, which is compatible with insulinoma. A 75 g oral glucose tolerance test (75 g OGTT) showed impaired glucose tolerance. An abdominal CT scan revealed a mass lesion in the uncinate process of the pancreas, a finding consistent with the results of angiography and selective artery calcium injection test. The patient then underwent a pancreaticoduodenectomy; the pancreatic mass was histologically diagnosed as benign insulinoma. After surgery, a prolonged 24 h fast caused no hypoglycaemia and the glucose tolerance capacity in 75 g OGTT improved. Eight months after surgery, the patient's body weight had reduced by 10 kg. This is therefore a case of concurrent insulinoma and impaired glucose tolerance.

Original languageEnglish
Article number213793
JournalBMJ Case Reports
Publication statusPublished - 04-01-2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Medicine(all)


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