Gastric Carcinoids: Classification and Diagnosis

Abstract

Gastric carcinoids are a subset of neuroendocrine tumors with a distinct pathogenesis and classification. Overall incidence has been increasing with the growing availability and use of endoscopy. There are three major types of gastric carcinoid. Type I and type II carcinoids are driven by the presence of hypergastrinemia and generally progress with a benign disease course. Type I is associated with type A chronic atrophic gastritis and type II is associated with Zollinger-Ellison syndrome in patients with multiple endocrine neoplasia type 1. In contrast, type III gastric carcinoids arise sporadically, have a much higher incidence of metastasis, and carry a graver prognosis. As symptoms are frequently nonspecific or minimal, diagnosis is often made incidentally on routine or surveillance endoscopy. Carcinoid syndrome is very rare with these tumors and presents in an atypical manner. The mainstay of treatment is endoscopic removal of small lesions with no evidence of invasion. Aggressive surgical therapy is reserved for larger invasive tumors or patients with type III tumors.