The purpose of this exhibition is to present a check list of basic features to analyse in a gastrointestinal tumor, the CT imaging features that can guide the radiologist towards the diagnosis of Gastrointestinal stromal tumors (GISTs), and a correlation of the radiological findings with their pathologic features in order to better understand the imaging findings.

Gastrointestinal stromal tumors are a group of mesenchymal neoplasms that are distinct from true smooth muscle and neural tumors. They are the most common nonepithelial tumors of the gastrointestinal tract and account for 90% of mesenchymal tumors. The esophagus is the only exception where leiomyomas predominate (75% of esophageal mesenchymal tumors are leiomyomas; 25% are GISTs) [1,5]. Epidemiology It is estimated that approximately 5000–10,000 people are affected per year by this tumor all over the world [10]. However, their true frequency is unknown. Epidemiologic data...

Imaging modality and protocol Imaging plays a very important role in the diagnosis, treatment planning, and follow-up of GI tumors. It allows: an adequate characterization of the tumor and its relation with the gastrointestinal wall and near structures proper staging prognosis assessment follow-up during specific treatment Contrast-enhanced CT is the imaging method of choice. Oral as well as IV contrast should be administered to define the bowel margins and for an adequate stomach distention. Both positive and negative oral contrast agents can be used, but...

The increasing diagnosis of GISTs and the long-term survival rates after treatment have made imaging and pathology increasingly important, not only for diagnosis, but also for monitoring the effects of treatment and detecting tumor progression. The clinical information and image findings can help narrow the diagnosis of sub epithelial neoplasms and distinguish certain characteristics highly suggestive of GIST. A correlation of imaging features and pathological findings not only makes the diagnosis but helps to determine the risk and treatment plannig.

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