Case Report
Copyright ©2013 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastrointest Surg. Mar 27, 2013; 5(3): 68-72
Published online Mar 27, 2013. doi: 10.4240/wjgs.v5.i3.68
Pancreatic insulinoma combined with glucagon positive cell: A case report
Suguru Yamashita, Nobutaka Tanaka, Michiro Takahashi, Motoki Nagai, Takatoshi Furuya, Yoshio Suzuki, Yukihiro Nomura
Suguru Yamashita, Nobutaka Tanaka, Michiro Takahashi, Motoki Nagai, Takatoshi Furuya, Yukihiro Nomura, Department of Surgery, Asahi General Hospital, Chiba 289-2511, Japan
Suguru Yamashita, Department of Surgery, Kanto Medical Center NTT EC, Tokyo 141-8625, Japan
Yoshio Suzuki, Department of Pathology, Asahi General Hospital, Chiba 289-2511, Japan
Author contributions: Yamashita S and Tanaka N contributed to the study concept and design; Yamashita S and Takahashi M contributed to acquisition of data; Nagai M, Furuya T and Tanaka N contributed to analysis and interpretation of data; Yamashita S, Tanaka N, Nomura Y and Suzuki Y contributed to drafting of the manuscript.
Correspondence to: Suguru Yamashita, MD, Department of Surgery, Kanto Medical Center NTT EC, Higashi-Gotanda 5-9-22, Shinagawa-ku, Tokyo 141-8625, Japan. origin0304@yahoo.co.jp
Telephone: +81-3-34486251 Fax:+81-3-34486558
Received: October 10, 2012
Revised: January 23, 2013
Accepted: February 5, 2013
Published online: March 27, 2013
Abstract

We present a 70-year-old man who was referred for surgery with uncontrollable hypoglycemia. Ultrasonography and abdominal contrast computed tomography revealed a hypervascular tumor of 1 cm in diameter in the pancreatic tail. With a diagnosis of insulinoma, we performed a distal pancreatectomy. The patient showed a good postoperative course without any complications. The patient’s early morning fasting hypoglycemia disappeared. The respective levels of C-peptide and insulin dropped from 14.9 ng/mL and 4860 μIU/mL preoperatively to 5.3 ng/mL and 553 μIU/mL after surgery. A histopathological examination demonstrated that the tumor was a pancreatic neuroendocrine tumor, grade 1. Immunostaining was negative for insulin and positive for CD56, chromogranin A, synaptophysin and glucagon. These findings suggested that the tumor was clinically an insulinoma but histopathologically a glucagonoma. Among all insulinoma cases reported between 1985 and 2010, only 5 cases were associated with independent glucagonoma. In this report, we characterize and discuss this rare type of insulinoma by describing the case we experienced in detail.

Keywords: Hypoglycemia, Insulinoma, Pancreas, Neuroendocrine tumor, Glucagon