Pathologic aspects of gastrinomas in patients with Zollinger-Ellison syndrome with and without multiple endocrine neoplasia type I.

During the three decades since the recognition of the Zollinger-Ellison syndrome (ZES), major progress has been made in the diagnosis and treatment of this disease. However, the many failed operations in patients with ZES, the existence of primary lymph node gastrinomas, and the surgical approach of patients with ZES and multiple endocrine neoplasia type I (MEN-I) have remained controversial issues. In this review, our experience with the pathology of immunocytochemically identified gastrinomas in 44 patients with ZES is presented and related to the relevant literature. (1) Gastrinomas occur frequently in the duodenum (> 40%) and are commonly small (< 1 cm). They can therefore easily be missed at surgical exploration; lymph node metastases from such occult gastrinomas may be mistaken for primary tumors. (2) Most pancreatic gastrinomas reside in the head of the gland and have a diameter of 1 to 3 cm. (3) Gastrinomas associated with MEN-I are predominantly of duodenal origin and frequently multicentric; sporadic gastrinomas are single and more often pancreatic. Because MEN-I associated pancreatic tumors seldom contain gastrin, ZES in MEN-I patients is almost never cured by resection of the pancreatic tumors. (4) The metastatic potential of most small duodenal gastrinomas seems to be restricted to the regional lymph nodes.