Studies have shown that the duodenum is a more common site (30-40%) of primary
gastrinomas than previously reported. These
tumors are often occult to conventional exploration, and their detection requires duodenotomy and meticulous evaluation of the mucosa by eversion and direct palpation. Furthermore,
tumors as small as 1 to 2 mm may be associated with
lymph node metastases. Seven patients with duodenal
gastrinomas treated during a 2-year period are reported. Four had sporadic
Zollinger-Ellison syndrome (ZES), and three had
multiple endocrine neoplasia type I (MEN-I) syndrome. All seven patients had malignant duodenal
gastrinomas as proved by metastatic lymph nodes and in one case a large liver
metastasis as well. Local excision of the
tumor,
lymph node excisions, and in one case liver lobectomy resulted in eugastrinemia in the 4 with sporadic ZES. Two of the three with MEN-I were also eugastrinemic after similar procedures, with the addition of distal
pancreatectomy. Duodenotomy is considered an essential procedure in sporadic ZES patients when no pancreatic
tumor is found and in all MEN-I/ZES patients, regardless of the pancreatic findings. Regional
lymph node excisions are essential when a duodenal
tumor has been found.