Lymph Node Gastrinoma in Multiple Endocrine Neoplasia Type 1-a Diagnostic Challenge

Background: Gastrinomas are the most frequent hormonally-active neuroendocrine tumours in patients with multiple endocrine neoplasia type 1 (MEN1). Case Report: We report on the diagnostic difficulties in a 62-year-old female patient with MEN1 and lymph node gastrinoma. At six and twelve months after resection of a lymph node gastrinoma, no signs of recurrence were observed. Basal and peak gastrin levels during secretin stimulation test were normalized. Extensive explorations, including gastrointesinal endoscopy, endoscopic ultrasonography, and Ga-68-DOTATOC-PET/CT, did not reveal a primary duodenal or pancreatic tumour. Conclusion: Localization of gastrinomas in patients with MEN1 is challenging due to their small size, frequent duodenal location, and multiplicity. Therefore, while some studies support the existence of primary lymph node gastrinoma in patients with sporadic disease, this diagnosis should not be made in MEN1 patients. In both cases, however, extensive follow-ups are required