Gastrointestinal Stromal Tumor of Small Intestine Presenting with Ileocolic Intussusception in an Adult - A Rare Case with Review of Literature

Abstract

ABSTRACT Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal (GI) tract (1% to 2% of GI malignant tumors). They are most commonly located in the stomach (50 to 60%) and rarely in the small intestine (20-25% of all cases). The hallmark of most GISTs is their positivity for KIT (CD117) and DOG-1. Intussusception occurs rarely in adults with an incidence of approximately 2-3 per 1L per year. It represents 5% of all intussusceptions and is the cause of 1% of all intestinal obstructions. Ileocolic intussusception in adults is a unique variant in which most cases have a malignant lead point. In our case, we report an elderly patient presenting with intestinal obstruction, and imaging showed ileocecal intussusception with a solid nodular growth arising from the ileum. On exploration, the tumor was intraluminal arising from the ileum with ileocecal intussusception. Adhering to oncological principles, a right hemicolectomy was performed. The final pathologic diagnosis indicated the GIST of the ileum. Immunohistochemistry (IHC) showed CD117 negative and DOG-1 positive. Bowel obstruction due to intussusception in adults is rare. GIST in the ileum causing intussusception is unusual with a poorer prognosis than other GISTs. Intussusception in adults obstructing with small intestinal GIST which is CD117 negative makes it interesting and even rare. The diagnosis of intussusception and GISTs causing obstruction in adults is delicate, and timely surgical treatment can be vital. Given a high risk of malignancy, primary surgical resection using oncologic principles presents the best option in this scenario.