Thymic neuroendocrine tumor in a patient with multiple endocrine neoplasia type I : The limitations of surveillance

Abstract

Multiple endocrine neoplasia type I (MEN1) is an autosomal dominant disorder associated with pituitary and parathyroid adenomas and neuroendocrine tumors (NETs) of the pancreas. Pancreatic NETs, most of which are non-functional, are now the primary life-threatening manifestation of MEN1. Some patients with this disorder develop NETs of the thymus, which are typically characterized by aggressive behavior and malignant potential. Although rare in the general population, 25% of all reported thymic NETs have occurred in patients with MEN1. With the aid of advancements in imaging and biomarkers, the clinician is now better equipped in detecting NETs in this high-risk group. In this report, we present a patient whose incidentally discovered thymic NET led to the diagnosis of MEN1. We provide an overview of MEN1-associated NETs with a specific focus on the use of chromogranin A (CgA) in disease surveillance.