Insulin and Somatostatin Releasing Islet Cell Tumor Caused Hypoglycemia.

Abstract

Wereport a hypoglycemic case with normal insulin levels, which was caused by an islet cell tumor that was releasing insulin and somatostatin. Afasting test suggested the over secretion of insulin. Moreover, this hypoglycemiawas enhanced by the inhibitory effect of somatostatin on the secretion of insulin counter-regulatory hormones, such as glucagon, in addition to the autonomoussecretion of insulin from the tumor. In cases of hypoglycemia with apparently normal insulin levels, the measurement of somatostatin and various provocative tests are recommended. Arterial stimulation venous sampling (ASVS)was useful to detect the location of this functioning islet cell tumor. (Internal Medicine 40: 324-330, 2001)

Large Duodenal Somatostatinoma in the Third Portion Associated with Severe Glucose Intolerance

“…Reports of glucose intolerance with somatostatinoma are inconsistent. Some reports show that the somatostatinoma induced serious hyperglycemia with ketoacidosis (8), while others report hypoglycemia (9). Other reports show that the serum insulin level with somatostatinoma is within the normal range (10) Glucagon loading test C-peptide (basal) (6 min) 300 pg/ml 53 pg/ml 180 pg/ml 33 pg/ml 8.2 pg/ml 1.64 ng/ml (not measured) 29.7 U/ml* 161 mg/dl* 11.81* 10.0% 3.06 ng/ml 9.28 ng/ml 10 pg/ml 81 pg/ml 380 pg/ml 38 pg/ml 33.9 pg/ml 2.36 ng/ml 8.0 g/dl 5.9 U/ml 85 mg/dl 1.24 4.9%** 1.61 ng/ml** 6.40 ng/ml** (1.0 12 pg/ml) (40 180 pg/ml) (<200 pg/ml) (15 86 pg/ml) (9 52 pg/ml) (<0.42 pg/ml) (4.0 18.3 g/dl) (1.8 11.3 U/ml) (4.3 5.8%) (0.94 2.80 ng/ml) *under insulin therapy, **the data after 90 days of the operation.…”