Tanaka Nagaaki, Hosoi Masayuki, Yamamoto Tsunehiko, Yoshioka Katsunobu, Ishii Tomofusa, Sato Toshihiko, Tanaka Shiro, Yamazaki Osamu, Manabe Takao, Toyokawa Akihiro, Fujii Satoru
Department of Metabolism and Endocrinology, Osaka City General Hospitala, Osaka.
Intern Med. 2002 Oct;41(10):839-41. doi: 10.2169/internalmedicine.41.839.
A 76-year-old woman suffered from somnolence while fasting for almost 2 years. Fasting plasma glucose (FPG) (40 mg/dl) and the immunoreactive insulin (IRI) level (8.8 microU/ml) were not compatible with Fajan's ratio or Turner's ratio observed in typical insulinoma. The secretin test showed no response to insulin secretion, suggesting the presence of insulinoma. Abdominal dynamic computed tomography (CT) revealed a 12-mm hypervascular lesion in the head of the pancreas. A selective arterial calcium infusion test (SACI) was performed, during which IRI in the hepatic venous blood was measured following selective intraarterial calcium infusion. An increase in IRI levels in the gastroduodenal and superior mesenteric arteries suggested the presence of a functional insulinoma in the head of the pancreas. Enucleation of the tumor improved FPG and IRI levels to 138 mg/dl and 3.8 microU/ml, respectively. After surgery, a secretin test showed a 5-fold increase in IRI levels, suggesting normal beta cell function. This case illustrates the value of the secretin test for the diagnosis of insulinoma and for the postoperative assessment of beta cell function. It further illustrates the value of the SACI for localizing an insulinoma.
一名76岁女性在禁食近2年期间出现嗜睡症状。空腹血糖（FPG）为40mg/dl，免疫反应性胰岛素（IRI）水平为8.8微单位/毫升，这与典型胰岛素瘤中观察到的法扬斯比率或特纳比率不相符。促胰液素试验显示对胰岛素分泌无反应，提示存在胰岛素瘤。腹部动态计算机断层扫描（CT）显示胰腺头部有一个12毫米的高血管病变。进行了选择性动脉钙注入试验（SACI），在选择性动脉内注入钙后测量肝静脉血中的IRI。胃十二指肠动脉和肠系膜上动脉中IRI水平升高提示胰腺头部存在功能性胰岛素瘤。肿瘤摘除术后，FPG和IRI水平分别提高到138mg/dl和3.8微单位/毫升。术后促胰液素试验显示IRI水平增加了5倍，提示β细胞功能正常。该病例说明了促胰液素试验在胰岛素瘤诊断和术后β细胞功能评估中的价值。它进一步说明了SACI在胰岛素瘤定位中的价值。
