Islet hyperplasia in adults: challenge to preoperatively diagnose non-insulinoma pancreatogenic hypoglycemia syndrome.
BACKGROUND
Pancreatic hyperfunctional islet hyperplasia in adults has been more and more frequently described in the literature. Postprandial neuroglycopenia, a negative normal fasting test, negative pancreatic imaging results, and positive intra-arterial calcium stimulation of serum insulin are characteristic. In affected patients the term non-insulinoma pancreatogenic hypoglycemia syndrome (NIPHS) was proposed. MATERIALS AND METHODS/PATIENTS: We also encountered fasting hypoglycemia in such patients and therefore evaluated clinical and biochemical data in patients with NIPHS (n = 11), patients with insulinoma (n = 70), and patients in whom hypoglycemia was ruled out (n = 70).


RESULTS
Patients with NIPHS were younger (median age: 41 years; range: 18-66) and mostly non-obese (median body mass index/BMI: 22.2 kg/m2; range: 19-39) compared with patients with an insulinoma (median age: 50 years; median: BMI 26.1 kg/m2). During an oral glucose tolerance test (OGTT) followed by a standard fasting test, neuroglycopenia was observed postprandially with a mean minimal blood glucose level of 36 +/- 9 mg/dl in 7 out of 11 patients. Spontaneous hypoglycemia during the fast was 38 +/- 5 mg/dl in 8 out of 11 patients. The corresponding insulin levels were 9.2 +/- 9.8 mU/l (OGTT) and 6.8 +/- 5.4 mU/l (fasting), significantly lower than in patients with insulinoma (P < 0.001), but not different from patients without hypoglycemia (P = 0.05). After pancreatic resection 8 patients (73%) were cured with enduring euglycemia. Pathohistological islet abnormalities with hyperplasia, hypertrophy, and microadenomatosis were confirmed in all patients.


CONCLUSIONS
In patients with postprandial and/or fasting neuroglycopenia NIPHS may be suspected when insulin levels are low but inadequately suppressed and localization studies failed to show a distinct pancreatic tumor.
Starke
Achim
A
Insulinoma and GEP Tumor Center Neuss-Düsseldorf, Lukaskrankenhaus Neuss, Preussenstrasse 84, Neuss, 41464, Germany. starkea@uni-duessel-dorf.de
Saddig
Christiane
C
Kirch
Barbara
B
Tschahargane
Cyrus
C
Goretzki
Peter
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D006965:Hyperplasia / Q000150:complications; D007003:Hypoglycemia / Q000175:diagnosis / Q000209:etiology*; D007340:Insulinoma / Q000175:diagnosis; D007515:Islets of Langerhans / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010182:Pancreatic Diseases / Q000150:complications / Q000175:diagnosis*; D010190:Pancreatic Neoplasms / Q000175:diagnosis
D001786:Blood Glucose