A Mass in the Thorax: A Rare Presentation of Gastrointestinal Stromal Tumor.

Gastrointestinal stromal tumors (GIST) can occur anywhere in the gastrointestinal tract, with the primary site being the stomach. GISTs are often discovered incidentally on imaging due to the non-specific symptoms they present at the presentation. They can be distinguished from other mesenchymal tumors by immunohistochemistry staining. These tumors can range from benign to highly malignant, with surgical resection as the main treatment modality. Here, we present a case of a large GIST found not in the stomach, but in the mediastinum, incidentally on imaging, in a middle-aged male.