E2538. Imaging Findings of Rare Disease Entities in the Gastrointestinal Tract
  1. Xiaoyang Liu; University of Toronto
In addition to commonly encountered benign and malignant disease of the gastrointestinal (GI) tract, rare disease entities can occur, including both focal lesions and diffuse involvement of the stomach, small and large bowel. Relatively common lesions along the GI tract can also be seen in atypical locations or appearance, making the diagnosis challenging. Familiarity to these rare disease entities and common disease in rare locations are key for correct and prompt diagnosis. This review aims to review the very rare disease entities involving the GI tract, through a collection of case examples.

Educational Goals / Teaching Points
This educational exhibit aims to familiarize the audience with rare disease entities involving the stomach, small and large bowels. More common disease entities occurring at unusual location or with atypical appearance will also be discussed. The pathogenesis, clinical significance and management of these rare entities will be reviewed. We will also discuss imaging findings and their clinical relevance.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The rare disease entities of the GI tract to be discussed include both benign and malignant focal lesions, as well as more diffuse abnormality of the small and large bowel. Benign focal lesions: (ectopic pancreas in the stomach, colonic pneumatosis cystoides intestinalis). Malignant focal lesions:(malignant transformation of gastric teratoma, melanoma metastases in small and large bowel mimicking lymphoma, small bowel leiomyosarcoma, angiomyxoma of the ischioanal fossa). Diffuse involvement of small or large bowel: (tyrosine kinase inhibitor associated small bowel lymphangiectasia, small and large bowel amyloidosis).

Given the rarity of the discussed disease entities in the GI tract, it may be challenging to reach to correct diagnosis. Awareness of these rare diagnosis and recognition of the unusual imaging patterns of more common disease is key for treatment planning and patient management.