Insulinoma in a patient with NIDDM.
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.


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.
Kane
L A
LA
Department of Internal Medicine, Mayo Medical School, Rochester, MN 55905.
Grant
C S
CS
Nippoldt
T B
TB
Service
F J
FJ
D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications*; D005500:Follow-Up Studies; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology*; D007328:Insulin / Q000627:therapeutic use; D007340:Insulinoma / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000097:blood / Q000150:complications / Q000175:diagnosis* / Q000601:surgery
D001786:Blood Glucose; D007328:Insulin