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{{Insulinoma}}
{{Insulinoma}}
{{CMG}}{{AE}}{{PSD}}
{{CMG}}; {{AE}} {{ADS}}
 
==Overview==
==Overview==
Laboratory findings consistent with the diagnosis of insulinoma include serum [[glucose]] < 55 mg/dL, serum [[Insulin]] > 5-10 μU/mL, serum [[C-peptide|C-Peptide]] > 200 pmol/L, and serum [[proinsulin]] ≥ 22 pmol/L. Patients with insulinoma may have elevated [[insulin]] to [[glucose]] ratio of > 0.4, which is usually suggestive of insulinoma after a 72-hour fast test([[Gold standard (test)|gold standard]] test). 33% patients have clinical symptoms within 12 hours of the fasting, 80% develop within 24 hours, 90% develop within 48 hours, and 100% develop within 72 hours.


==Laboratory Findings==


==Laboratory Tests==
*Laboratory findings consistent with the diagnosis of insulinoma include:<ref name="pmid19088155">{{cite journal| author=Cryer PE, Axelrod L, Grossman AB, Heller SR, Montori VM, Seaquist ER et al.| title=Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline. | journal=J Clin Endocrinol Metab | year= 2009 | volume= 94 | issue= 3 | pages= 709-28 | pmid=19088155 | doi=10.1210/jc.2008-1410 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19088155 }} </ref>
Laboratory findings consistent with the diagnosis of insulinoma include:<ref name="pmid23430217">{{cite journal| author=Okabayashi T, Shima Y, Sumiyoshi T, Kozuki A, Ito S, Ogawa Y et al.| title=Diagnosis and management of insulinoma. | journal=World J Gastroenterol | year= 2013 | volume= 19 | issue= 6 | pages= 829-37 | pmid=23430217 | doi=10.3748/wjg.v19.i6.829 | pmc=PMC3574879 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23430217 }} </ref>
** Serum [[glucose]] < 55 mg/dL
===Whipple's Traid===
** Serum [[Insulin]] > 5-10 μU/mL
The diagnosis of insulinoma is suspected in a patient with symptomatic fasting hypoglycemia. The conditions of [[Whipple’s triad]] need to be met for the diagnosis of insulinoma are:<ref name="pmid23430217">{{cite journal| author=Okabayashi T, Shima Y, Sumiyoshi T, Kozuki A, Ito S, Ogawa Y et al.| title=Diagnosis and management of insulinoma. | journal=World J Gastroenterol | year= 2013 | volume= 19 | issue= 6 | pages= 829-37 | pmid=23430217 | doi=10.3748/wjg.v19.i6.829 | pmc=PMC3574879 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23430217 }} </ref>
** Serum [[C-Peptide]] > 200 pmol/L
:1. [[Hypoglycemia]](plasma glucose < 50 mg/dL)
** Serum [[proinsulin]] ≥ 22 pmol/L
:2. Neuroglycopenic symptoms
*Patients with insulinoma may have elevated [[insulin]] to [[glucose]] ratio of > 0.4, which is usually suggestive of insulinoma after a 72-hour fast test. It is a [[Gold standard (test)|gold standard test]]. <ref name="pmid18672144">{{cite journal| author=Callender GG, Rich TA, Perrier ND| title=Multiple endocrine neoplasia syndromes. | journal=Surg Clin North Am | year= 2008 | volume= 88 | issue= 4 | pages= 863-95, viii | pmid=18672144 | doi=10.1016/j.suc.2008.05.001 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18672144 }} </ref>
:3. Reversibility of symptoms with administration of [[glucose]]
**33% patients develop clinical [[symptoms]] within 12 hours of the fasting
**80% develop clinical [[symptoms]] within 24 hours of the fasting
**90% develop clinical [[symptoms]] within 48 hours of the fasting
**100% develop clinical [[symptoms]] within 72 hours of the fasting


===Suppression tests===
==References==
The gold standard blood tests needed to diagnose insulinoma during a 72 hour fast are:<ref name="pmid23430217">{{cite journal| author=Okabayashi T, Shima Y, Sumiyoshi T, Kozuki A, Ito S, Ogawa Y et al.| title=Diagnosis and management of insulinoma. | journal=World J Gastroenterol | year= 2013 | volume= 19 | issue= 6 | pages= 829-37 | pmid=23430217 | doi=10.3748/wjg.v19.i6.829 | pmc=PMC3574879 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23430217  }} </ref>
{{Reflist|2}}
*Plasma [[glucose]] level
*[[Insulin]]
*[[C-peptide]]
*Pro-insulin
The sensitivity of combination of these 4 tests after 72h fasting is around 99%.


Normally, endogenous insulin production is suppressed in the setting of hypoglycemia.  A 72-hour fast, usually supervised in a hospital setting, can be done to see if insulin levels fail to suppress, which is a strong indicator of the presence of an insulin-secreting tumour.
{{WH}}
:During the test, the patient may have calorie-free and caffeine-free liquids.  Capillary blood glucose is measured every 4 hours using a [[glucose meter|reflectance meter]], until values < 60 mg/dL (3.3 mmol/L) are obtained. Then, the frequency of blood glucose measurement is increased to every hour until values are < 49 mg/dL (2.7 mmol/L).  At that point, or when the patient has symptoms of hypoglycemia, a blood test is drawn for serum glucose, insulin, proinsulin, and C-peptide levels.  The fast is stopped at that point, and the hypoglycemia treated with intravenous dextrose or calorie-containing food or drink.<br/>
{{WS}}


==References==
[[Category:Medicine]]
{{Reflist|2}}
[[Category:Endocrinology]]
[[Category:Up-To-Date]]
[[Category:Up-To-Date]]
[[Category:Oncology]]
[[Category:Medicine]]
[[Category:Gastroenterology]]
[[Category:Surgery]]

Latest revision as of 02:06, 27 November 2017

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Amandeep Singh M.D.[2]

Overview

Laboratory findings consistent with the diagnosis of insulinoma include serum glucose < 55 mg/dL, serum Insulin > 5-10 μU/mL, serum C-Peptide > 200 pmol/L, and serum proinsulin ≥ 22 pmol/L. Patients with insulinoma may have elevated insulin to glucose ratio of > 0.4, which is usually suggestive of insulinoma after a 72-hour fast test(gold standard test). 33% patients have clinical symptoms within 12 hours of the fasting, 80% develop within 24 hours, 90% develop within 48 hours, and 100% develop within 72 hours.

Laboratory Findings

  • Laboratory findings consistent with the diagnosis of insulinoma include:[1]
  • Patients with insulinoma may have elevated insulin to glucose ratio of > 0.4, which is usually suggestive of insulinoma after a 72-hour fast test. It is a gold standard test. [2]
    • 33% patients develop clinical symptoms within 12 hours of the fasting
    • 80% develop clinical symptoms within 24 hours of the fasting
    • 90% develop clinical symptoms within 48 hours of the fasting
    • 100% develop clinical symptoms within 72 hours of the fasting

References

  1. Cryer PE, Axelrod L, Grossman AB, Heller SR, Montori VM, Seaquist ER; et al. (2009). "Evaluation and management of adult hypoglycemic disorders: an Endocrine Society Clinical Practice Guideline". J Clin Endocrinol Metab. 94 (3): 709–28. doi:10.1210/jc.2008-1410. PMID 19088155.
  2. Callender GG, Rich TA, Perrier ND (2008). "Multiple endocrine neoplasia syndromes". Surg Clin North Am. 88 (4): 863–95, viii. doi:10.1016/j.suc.2008.05.001. PMID 18672144.

Template:WH Template:WS