The management of the hypoglycemic patient

Abstract

Organic hypoglycemia may be caused by an insulinoma. This is a rare tumor, multiple in about 10% and malignant in about 10% of cases. Multiplicity is particularly likely when insulinoma occurs as part of the MEN 1 syndrome. When a patient exhibits Whipple's triad, synchronous blood sugar and insulin estimations must be made, and repeated during fasting. Diagnosis depends on the finding of inappropriately high insulin levels in the presence of low blood sugars. Many stimulatory tests are available but none are as reliable as prolonged starvation, and probably should be abandoned.Measurement of proinsulin and C‐peptide are of particular value in the diagnosis and in elimination of factitious hypoglycemia.Preoperative localization is most useful and can be achieved in up to 90% of patients by skillful selective angiography. Percutaneous portal venous sampling has been used and is particularly indicated in patients after a fruitless first exploration.Tumors of the body and tail are usually treated by distal pancreatectomy, those of the head by enucleation. There is a risk of pancreatic fistula, and duct damage can be unmasked by secretin injection. Occult tumors and hyperplasia may require “blind” progressive distal resection with blood sugar monitoring until the hypoglycemia is controlled, but this is something of a desperation measure. In malignant tumors, hypoglycemia may be controlled by diazoxide or somatostatin. Streptozotocin may control the syndrome and lead to prolongation of life. Like other malignant apudomas, these tumors are usually slow growing and relatively benign.

Preoperative imaging versus intraoperative localization of tumors in adult surgical patients with hyperinsulinemia: A multicenter study of 338 patients

“…It is not significantly more expensive to study the pancreas after the liver, even though only 1 tumor in 5 will be found, and these tumors found have a diameter in excess of 10 mm [5]. Computed tomographic scanning hardly appears to be more useful than ultrasound and is much more expensive [6][7][8][9]. In our view, CT scanning for insulinoma should be abandoned in routine practice and used only in those research centers with the most modern equipment [10].…”

The ultrasonic detection of insulinomas during surgical exploration of the pancreas

“…The surgical management is strongly influenced by the morphological features of the tumor on the one hand and the possibilities of localization on the other [36]. Fourteen percent of these tumors have sizes less than 1 cm and cannot be visualized preoperatively, despite good diagnostic procedures [8,11].…”

Surgery for benign insulinoma: An international review

“…Among 72 patients, published from the Mayo Clinic, only 2 had Whipple procedures [2]. Most authors agree that the Whipple procedure is too radical a therapy for a benign insulinoma of the head of the pancreas [3,18]. In this multiinstitutional review, enucleation was the procedure of choice for insulinomas in the head of the pancreas.…”