Insulinomas: localization with selective intraarterial injection of calcium.
ABSTRACT To facilitate the noninvasive preoperative localization of islet cell tumors less than 15 mm in diameter, the authors examined the use of calcium as an insulin secretagogue in an arterial stimulation venous sampling (ASVS) technique. In four patients with episodic hypoglycemia, calcium gluconate (0.01-0.025 mEq Ca2+/kg) was injected directly into branches of the celiac plexus (gastroduodenal, splenic, and hepatic arteries) and the superior mesenteric artery. In all patients, serum levels of insulin rose abruptly in blood samples taken from the right hepatic vein 30 and 60 seconds after the infusion of calcium into the artery supplying the tumor; injection into an artery not supplying the tumor did not result in a similar rise. Accurate localization of the insulinomas was verified at surgery in three patients. In the fourth patient, who did not undergo surgery, arteriographic results were positive for insulinoma at the predicted site. On the basis of these results, the authors believe noninvasive ASVS may replace invasive portal venous sampling as the most effective method for the localization of occult insulinomas.
Annals of internal medicine 08/1995; 123(4):269. DOI:10.7326/0003-4819-123-4-199508150-00004 · 16.10 Impact Factor
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ABSTRACT: Background Although fasting hypoglycemia has historically been considered the hallmark of insulinoma, postprandial hypoglycemia has also been occasionally reported as the predominant feature. We report a rare case of an insulinoma diagnosed in an individual presenting exclusively with postprandial hypoglycemia without fasting hypoglycemia. Case Report A 47-year-old woman with medical history of migraine, depression, hypercholesterolemia, iron deficiency anemia, and peptic ulcer disease presented with complaints of frequent episodes of dizziness, blurring of vision, and anxiety over the past 4 months. These episodes usually occurred 1-2 hours after eating and resolved with ingestion of sugary foods. Home glucometer readings during typical symptoms were 47-64 mg/dL. Physical exam revealed a healthy-appearing middle-aged female with BMI of 28. Laboratory data after an overnight fast showed serum blood glucose 77mg/dL and AM cortisol 9.6 (5-25 µg/dl). Hemoglobin A1C, thyroid function tests, IGF-1, liver function tests, and kidney function were in normal range. She was instructed to bring a typical meal to the clinic for monitoring of postprandial glucose levels. Three hours after ingestion of the meal, she developed typical adrenergic symptoms during which laboratory analysis revealed a serum glucose level of 44 mg/dL, C-peptide of 2.9 (0.8-3.1ng/ml), insulin level of 32 (0-17 µIU/lt), negative sulfonylurea screen, and insulin antibodies. She was treated with 15 grams of oral glucose, which alleviated her symptoms. Medical therapy with acarbose was attempted, but did not lead to significant reduction in hypoglycemic events. CT abdomen/pelvis confirmed the presence of a tumor in the tail of the pancreas. The patient subsequently underwent partial pancreatectomy, splenectomy, and lymph node resection, with resolution of symptoms. Histopathological analysis confirmed insulinoma. Conclusions We present a rare case of an insulinoma in the setting of verified postprandial hypoglycemia with elevated insulin and C-peptide levels. Although insulinomas typically present with fasting hypoglycemia, it is important to consider insulinoma in the differential diagnosis of patients presenting exclusively with postprandial hypoglycemia.11/2014; 15:488-91. DOI:10.12659/AJCR.891336
Article: LOCALIZATION OF INSULINOMAS[Show abstract] [Hide abstract]
ABSTRACT: Purpose: To examine the value of superselective arterial stimulation venous sampling (ASVS) to localize insulinomas.Material and Methods: Superselective ASVS (SS-ASVS) was performed in 9 patients with insulinoma. Injection of secretagogue (calcium gluconate: 0.01 mEq Ca++/kg) was performed into the gastroduodenal, splenic (proximal and distal), and superior mesenteric arteries in 9 patients and additionally into the dorsal pancreatic artery in 6 patients. Sampling from the hepatic vein was performed to measure serum insulin concentrations at 30, 60 and 120 s after each injection of secretagogue into these arteries. SS-ASVS results were correlated with surgical findings, compared to those of conventional ASVS.Results: Insulinomas were correctly localized to the head, body or tail of the pancreas by SS-ASVS in 8 patients (89%). Conventional ASVS detected insulinomas in 7 patients (78%), although it could not distinguish whether the insulinoma was located in the pancreatic body or tail in 4 of the 7 patients. There were eight-fold or more increases in serum insulin levels in hepatic venous samples related to the artery supplying the tumor in 8 patients. Localization of the insulinomas was verified at surgery in all patients.Conclusion: SS-ASVS is a useful method for detailed evaluation of overproduction of insulin from pancreatic insulinomas and their localization. When the pancreatic insulinoma is situated in the pancreatic body or tail, the localization is more accurately made by SS-ASVS than by conventional ASVS.Acta Radiologica 03/2000; 41(2). DOI:10.1034/j.1600-0455.2000.041002172.x · 1.35 Impact Factor