Reuters Health Information: Test differentiates insulinoma from diffuse nesidioblastosis
Test differentiates insulinoma from diffuse nesidioblastosis
Last Updated: 2015-09-04
By Reuters Staff
NEW YORK (Reuters Health) - Selective arterial calcium
stimulation (SACST) with hepatic venous sampling can
differentiate insulinoma from diffuse nesidioblastosis, report
researchers from the Mayo Clinic, Rochester, Minnesota.
"Patients with endogenous hyperinsulinemic hypoglycemia and
negative or inconclusive noninvasive imaging present a
diagnostic and management challenge as both occult insulinoma
and noninsulinoma pancreatogenous hypoglycemic syndrome (NIPHS)
resulting from diffuse nesidioblastosis must be considered in
the differential diagnosis," note Dr. Scott Thompson and
colleagues.
"SACST with hepatic venous sampling is an interventional
radiologic technique used preoperatively to localize or
regionalize occult insulinoma with a sensitivity >90% in
multiple large series. The SACST technique is based upon the
observation that exogenous intraarterial calcium differentially
stimulates the release of insulin from abnormal pancreatic beta
cells but not normal beta cells," they explain.
To gauge the ability of SACST to differentiate insulinoma
from diffuse nesidioblastosis, the Mayo team reviewed data from
116 patients with biochemical evidence of endogenous
hyperinsulinemic hypoglycemia and negative or inconclusive
noninvasive imaging who underwent SACST prior to pancreatic
exploration. Forty-two patients were later confirmed
(surgically and pathologically) to insulinoma, while 74 had
nesidioblastosis.
The team found that the mean maximum hepatic venous insulin
concentration (mHVI) was 22 times higher and the average
relative-fold increase in hepatic venous insulin concentration
(rHVI) was nearly 4 times higher in patients with insulinoma
relative to those with diffuse nesidioblastosis.
"Importantly, the ROC curves demonstrated that both mHVI and
rHVI could differentiate insulinoma from nesidioblastosis with
high specificity," the researchers reported in the Journal of
Clinical Endocrinology and Metabolism online August 27. "Of
note, the AUC was higher for mHVI compared to rHVI, 0.94 and
0.83, respectively, suggesting that mHVI has a slightly better
diagnostic performance than the rHVI."
"Given the high specificity of both the mHVI and rHVI for
differentiating occult insulinoma from diffuse nesidioblastosis,
SACST may be useful for identifying only those patients with a
high likelihood of an occult insulinoma for pancreatic
exploration while preventing patients with diffuse
nesidioblastosis from undergoing unnecessary surgery prior to a
trial of conservative management," the researchers conclude.
They say further studies are needed to validate their
findings to "better define the role of SACST when clinicians are
faced with a patient with endogenous hyperinsulinemic
hypoglycemia and negative or inconclusive localization studies."
The study had no commercial funding and the authors have no
disclosures.
SOURCE: http://bit.ly/1KuoX0u
J Clin Endocrinol Metab 2015.
|