E1550. What Tumors Can You Stomach? A Review of Gastric Tumors
  1. Adam Kinzel; University of California - Los Angeles
Gastric tumors present an interesting diagnostic challenge. While the majority of gastric tumors are adenocarcinoma (>90%), which are often diagnosed via esophagogastroduodenoscopy, there are multiple gastric tumors (both benign and malignant) where imaging can lead to an accurate diagnosis. The purpose of this educational exhibit is to provide an overview of non-adenocarcinoma gastric tumors and discuss the relevant imaging features and histopathologic findings of these tumors.

Educational Goals / Teaching Points
By the end of the exhibit, the viewer will be able to describe the spectrum of gastric tumors as well as the epidemiology and risk factors, clinical presentation, pathologic findings, and imaging features of these tumors. These lesions will be divided into both benign (glomus tumors, schwannomas, lipomas, and leiomyomas) and malignant tumors (gastrointestinal stromal tumors, carcinoids, lymphomas, and mucinous carcinomas). Finally, the viewer will be able to understand the treatment and surveillance for these tumors as well as recognize potential tumor complications.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Diagnosis of gastric tumors is often challenging due to the rarity of these lesions and the need for adequate gastric distension with oral contrast to avoid tumor mimics, such as ingested material or gastric folds. The most common protocol to adequately diagnosis gastric tumors is using a multiphase pre and postcontrast CT in the arterial and portovenous phases. The precontrast images allow for detection of calcifications, hemorrhage, and fat. The postcontrast images help determine the enhancement characteristics of these tumors, differentiate mucosal versus submucosal tumors, and evaluate growth patterns as well as disease extent. It is also important to insure the patient has fasted prior to the examination in order to achieve adequate distention of the stomach with oral contrast.

Gastric tumors are a rare group of tumors that present a challenging clinical diagnosis and often go undetected for many years. Radiologists play a vital role in both the detection and characterization of these tumors as well as guide effective clinical management in these patients. Familiarity with the imaging appearances of these tumors can help physicians make an accurate diagnosis and in certain cases avoid unnecessary procedures and complex surgeries in these patients.