Presentation and Outcome of Pancreaticoduodenal Endocrine Tumors in Multiple Endocrine Neoplasia Type 1 Syndrome

Aim: To assess presentation and outcome of pancreaticoduodenal endocrine tumors (PDETs) in a single center series of multiple endocrine neoplasia type 1 (MEN1) patients. Methods: Retrospective analysis of prospectively collected data of MEN1 patients observed at the University of Verona. Results: Thirty-one MEN1 patients had PDETs, including 16 nonfunctioning (NF), 6 insulinomas and 9 Zollinger-Ellison syndrome (ZES). In 16 of these patients (52%), PDET was the manifestation which led to the diagnosis of MEN1; among this group, 15 patients (94%) previously had unidentified primary hyperparathyroidism (PHPT), which was asymptomatic in 9 cases (60%). Of the 31 patients, 19 (61%) underwent curativesurgery and 13 (68%, 7 NF-PDETs, 4 insulinomas and 2 ZES) were disease-free after a median follow-up of 3 years (range: 0.5-15). One patient had debulking surgery with stable disease after 2 years of follow-up. Eight patients with NF-PDETs ≤20 mm and 2 with ZES, treated with a conservative approach, showed stable disease. One patient with insulinoma was lost to follow-up. Conclusions: PDET may be the manifestation that leads to MEN1 diagnosis since the almost constant presence of PHPT is very often unrecognized or considered sporadic. Conversely, the presence of PDETs should be looked for in all patients presenting PHPT, even if asymptomatic, particularly before age 50. Surgery may be curative in the majority of insulinomas and can prolong disease-free survival in NF-PDET, but is not proven to be effective in ZES. A conservative approach can be safely reserved for patients with NF-PDETs ≤20 mm.