Which of the following are true concerning islet cell neoplasms of the pancreas in patients with MEN type 1?

D. All of the above.

DISCUSSION: The pathologic change in the pancreas of patients with MEN 1 is typically multicentric. Diffuse hyperplasia of islet cells and microadenoma formation are often identified in areas of the gland distant from grossly evident tumor. Tumors are commonly multifocal. Islet cell neoplasms of the pancreas occur in 30% to 80% of patients with MEN 1. The most common islet cell neoplasm in these patients is gastrinoma. Gastrinomas associated with MEN 1 probably account for 20% to 50% of all cases of the Zollinger-Ellison syndrome. The second most common islet cell tumor is insulinoma. Other pancreatic islet cell neoplasms, such as glucagonoma, somatostatinoma, or vasoactive intestinal polypeptide neoplasm (VIPoma), are rarely associated with MEN 1. Approximately 10% of insulinomas and approximately 15% or more of gastrinomas in patients with MEN 1 are malignant.