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range 108-881 ng/mL). To further confirm these findings, of hypoglycemia and pancreatic lesion when clinical,
immunohistochemical staining was performed for IGF-II biochemical, and immunohistochemical data are not
and the pancreatic tumor specimen was positive for IGF- consistent with insulinoma. In our patient, the finding of
II. These findings were consistent with the diagnosis of empty sella could have justified GH deficiency, so IGF-II
a pancreatic IGF-II-secreting tumor. The patient did not was not immediately evaluated. Although insulin was not
experience any other hypoglycemic symptoms during suppressed in our case, the finding of negative insulin and
follow up and completely recovered after surgery. positive IGF-II at immunostaining support the hypothesis
of an IGF-II secreting tumor. Furthermore the prompt
DISCUSSION resolution of signs and symptoms of hypoglycemia soon
after the resection of the pNET may be attributed to the
Hypoglycemia represents a relatively common biochemical normalization of serum IGF-II levels.
finding, which may be due to many causes, such as non-
islet cell tumor, drugs, organ failure, endocrine diseases, Financial support and sponsorship
hypopituitarism, or inborn errors of metabolism. A careful Nil.
clinical history, together with biochemical and radiological
assessments is essential to identify the underlying cause. Conflicts of interest
Although rare, insulinoma is the most frequent F-pNET. There are no conflicts of interest.
Biochemical criteria for insulinoma comprise documented
hypoglycemia (plasma glucose ≤ 55 mg/dL), concomitant Patient consent
inappropriately high plasma insulin ≥ 3 mU/mL, C-peptide Obtained.
≥ 0.6 ng/mL (≥ 0.2 nmol/L), proinsulin levels (≥ 5 pmol/L),
and no detectable hypoglycemic agent levels or circulating Ethics approval
antibodies to insulin. [6,7] The 72 h fasting test is considered The patient was treated within the standards of our institute
the gold standard for diagnosis of insulinoma. In the and the report was approved.
present case the occurrence of hypoglycemia together with
a pancreatic lesion lead to suspect an insulinoma. REFERENCES

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and ketogenesis. The IGF-II in serum is usually synthesized Y, Kobayashi M, Hanazaki K. Diagnosis and management of
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[9]
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Journal of Cancer Metastasis and Treatment ¦ Volume 2 ¦ August 31, 2016 ¦ 347