Diabetes Care, Vol 16, Issue 9 1298-1300, Copyright © 1993 by American Diabetes Association
Insulinoma in a patient with NIDDM
LA Kane, CS Grant, TB Nippoldt and FJ Service
Department of Internal Medicine, Mayo Medical School, Rochester, MN 55905.
OBJECTIVE--To confirm insulinoma as the cause of hypoglycemia in a patient
with NIDDM and determine the frequency of the co-occurrence of these two
conditions. RESEARCH DESIGN AND METHODS--The patient underwent an
in-hospital prolonged fast (< or = 72 h), according to standard
protocol, and an ultrasound examination of the pancreas. All cases of
histologically confirmed insulinoma at this institution over the period of
1927-1992 were reviewed to determine the prevalence of pre-existent
diabetes mellitus. RESULTS--After 10 h of fasting, plasma glucose was low
(1.89 mM); plasma insulin (258 pM) and C-peptide (1.39 nM) were elevated in
the absence of sulfonylurea in the plasma. An insulinoma detected by
ultrasonography was removed surgically with subsequent reoccurrence of
insulin-requiring diabetes. Among 313 cases of insulinoma confirmed at this
institution, this patient is the only one with pre-existent diabetes
mellitus. CONCLUSIONS--Insulinoma occurs extraordinarily rarely in patients
with pre-existing NIDDM.