Insulinoma : Introduction

Comments:
Introduction: Insulinoma is the most common functioning pancreatic neuroendocrine tumor (PanNET) and accounts for 4-20% of all resected PanNETs. They occur over a wide age range with a peak incidence in the 60's. They are rare below the age of 30 years. Women are slightly more commonly affected than men (F:M = 3:2). They are usually found in (or are attached to) the pancreas. About 2% are extrapancreatic and may occur in duodenum, jejunum, ileum, or the splenic hilum. Most cases are sporadic; about 10% are seen in the setting of multiple endocrine neoplasia 1 (MEN 1).

The tumor cells synthesize unregulated amounts of insulin causing a hypoglycemic syndrome. It must be kept in mind that there are other extrapancreatic tumors that secrete insulin-like growth factors and can cause hypoglycemia. Examples include hepatocellular carcinoma and mesenchymal tumors like solitary fibrous tumor.

About this image: Distal pancreactectomy for an insulinoma that was located in the uncinate process of pancreas. The photograph shows a well-circumscribed round to oval tumor (upper right) measuring 1.2 cm in diameter. The microscopic examination showed insulinoma with cells arranged in gyriform and trabecular patterns. Detailed case history is in the next image.

Case courtesy of: Dr. Sanjay D. Deshmukh (Professor of Pathology) & Dr. J. M. Gadekar (Head of Surgery Dept.), Dr. Vithalrao Vikhe Patil Medical College & Hospitals, Ahmednagar, India.