Laparoscopic Distal Pancreatectomy for a Glucose-responsive Insulinoma

• Published in: The Japanese Journal of Gastroenterological Surgery Vol. 50; no. 6; pp. 445 - 453
• Main Authors: Asano, Daisuke, Ozawa, Naoko, Matsuda, Yusuke, Nishio, Yuichirou, Yuan, Bee, Baba, Hironobu, Kondo, Ito, Murayama, Tadao, Hoshino, Naoaki, Ono, Chihiro, Nishioka, Yoshinobu
• Format: Journal Article
• Language: Japanese
• Published: The Japanese Society of Gastroenterological Surgery 01.06.2017
• Subjects: arterial stimulation and venous sampling; glucose-responsive insulinoma; intraoperative ivGTT
• ISSN: 0386-9768; 1348-9372
• DOI: 10.5833/jjgs.2014.0251

A 57-year-old woman presented hypoglycemia during or after a meal. The laboratory findings, including endocrine hormone levels were within the normal range, but the 75 g-oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (ivGTT) indicated excessive insulin secretion and hypoglycemia. A starvation test showed no excessive insulin secretion. Dynamic CT showed a solitary tumor in the pancreatic tail, which was diagnosed as a glucose-responsive insulinoma. Angiography and arterial stimulation venous sampling results supported this diagnosis and showed no metastasis. We performed a laparoscopic spleen-preserving distal pancreatectomy. Additionally, we performed intraoperative ivGTT post-resection that indicated normoglycemia and normal insulin secretion, confirming the absence of residual tumor. To the best of our knowledge, this is the first report of an intraoperative GTT. Hence, we report a rare case of glucose-responsive insulinoma and the usefulness of intraoperative GTT.