| Theme |
Update on Pancreatic Neuroendocrine Tumors |
| Title |
Diagnosis of Insulinoma |
| Author |
Hisato Igarashi |
Igarashi Medical Clinic |
| Author |
Keijiro Ueda |
Department of Gastroenterology, Kitakyushu Municipal Medical Center |
| Author |
Nao Fujimori |
Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University |
| Author |
Tetsuhide Ito |
Neuroendocrine Tumor Centre, Fukuoka Sanno Hospital, International University of Health and Welfare |
| [ Summary ] |
Ninety percent of the cases with insulinoma are of the benign type. Therefore, curative resection is possible, for which correct diagnosis of insulinoma is essential. For the diagnosis of insulinoma, differential diagnosis of hypoglycemia symptoms, tumor localization, and examination of the association with multiple endocrine neoplasia type I are important. The manifestations of hypoglycemia symptoms are derived from hypoglycemic-damage of the central nervous system or autonomic nerve stimulation. The first step of the diagnosis is to suspect the hypoglycemia symptoms; the 48-hour fasting test followed by glucagon provocative test are useful for diagnosing the presence of insulinoma. For tumor localization, the conventional imaging sometimes cannot detect the small-sized insulinoma; however, endoscopic ultrasonography (EUS) and selective arterial secretagogue injection (SASI) test should be useful in such cases. We should also note that somatostatin receptor scintigraphy (SRS) results are negative for some cases with insulinoma. |