Case Report

Diagnosis and Localization of Insulinoma after Negative Laparotomy by Hyperinsulinemic, Hypoglycemic Clamp and Intra-Aterial Calcium Stimulation

Robert A. Ritzel¹, Berend Isermann¹, Tobias Schilling¹, Hanns-Peter Knaebel², Markus W. Büchler², Peter P. Nawroth¹

Keywords: hypoglycemia, insulinoma, hyperinsulinamic hypoglycemic clamp, C-peptide suppression, intra-arterial calcium stimulation

Abstract

A 40-year-old woman with recurrent episodes of hypoglycemia was referred because of suspected insulinoma. Prolonged fasting was discontinued after 24 h due to symptomatic hypoglycemia (29 mg/dl, glucose/insulin-ratio 0.34). Magnetic resonance tomography showed a small 0.3 cm lesion in the body of the pancreas. During subsequent surgery a pancreatic tumor could not be detected, neither by manual palpation nor intraoperative ultrasonography. A hyperinsulinemic, sequentially eu- and hypoglycemic clamp confirmed the biochemical diagnosis of endogenous hyperinsulinemia and intra-arterial calcium stimulation localized calcium responsive tissue in the feeding distribution of the superior mesenteric artery. An octreotide scan was negative. During relaparotomy, six weeks after the initial surgery, the pancreatic body and tail were resected and a ∼1 cm non-malignant insulinoma was found. Although the use of highly sensitive, and more sophisticated and expensive methods for the diagnosis and localization of insulinomas are not generally suggested, we recommend application of intra-arterial calcium stimulation if the tumor is not detected using conventional diagnostic procedures.

Fulltext: HTML , PDF (238KB)

This article has been cited by other articles:

	Invasive diagnostic procedures for insulinomas of the pancreas Nöldge G, Weber MA, Ritzel RA, Werner MJ, Kauczor HU, Grenacher L Radiologe 2009. 49(3):224-232
	Hypoglycaemia Mokan M Vnitr Lek 2008. 54(4):387-394
	Benign Pancreatic Tumors Reddy S, Wolfgang CL Surg Clin North Am 2007. 87(6):1359-1378