Challenges in diagnosing and treating pancreatic neuroendocrine tumours in patients with a multiple endocrine neoplasia type 1 (MEN1) syndrome

Multiple endocrine neoplasia type 1 (MEN1) syndrome is an autosomal dominant hereditary disorder characterised by coexistence of pancreatic neuroendocrine tumours (pNETs) with parathyroid and pituitary tumours. PNETs, including mostly non-functioning tumours, gastrinoma and insulinoma, occur in nearly 95% of MEN1 patients and account for over 50% of disorder-related mortality. Therefore, early initiation of screening for pNET using biochemical and imaging tests as well as appropriate surgical and systemic treatment are of particular importance for this group of patients. Currently, there are no clearly defined guidelines which determine the optimal methods for detection and treatment of pNET in MEN1. Caution should be exercised when applying the guidelines designed for patients with sporadic pNET to MEN1 patients as the clinical course of the disorder is slightly different, involving multifocality of lesions and younger age of patients at onset. This paper discusses the distinctive features and challenges in diagnosing and treating pNETs in MEN1 patients.