ENDOSCOPIC SNAPSHOT Small Bowel GIST: Clinical Presentation as Intussusception and Obscure Bleeding GIST do Intestino Delgado: Apresentação Simultânea Sob a Forma de Invaginação e Hemorragia Digestiva Obscura

∗ Corresponding author. E-mail address: [email protected] (S. Giestas). tumors and only 0.04% of small intestinal malignant neoplasms. GISTs may occur anywhere along gastrointestinal tract, but most commonly arise in the stomach (40--60%) and jejunum/ileum (25--30%). The clinical presentation of GISTs is highly variable depending on their size, location and presence of mucosal ulceration. Abdominal pain and gastrointestinal bleeding (when mucosal ulceration is present) are the most common symptoms or signs although persistent significant bleeding is unusual. Intussusception and subsequent obstruction is a very uncommon presentation of these lesions because of their tendency to grow in an extraluminal fashion. Very few cases of small bowel intussusceptions from stromal tumor in adults have been described in medical literature. Intussusception is rather infrequent in adults, accounting for 0.1% of all surgical admissions and 1--5% of mechanical bowel obstructions. In contrast to childhood, where intussusception is idiopathic in 90% of cases, in adults a definable pathologic lesion is established in over 90% of cases, with neoplasms considered to be the cause in 65% of them. Preoperative diagnosis is often difficult because the symptoms are nonspecific. Intussusception is correctly diagnosed preoperatively in only one-third of cases. The relative rarity of GISTs combined with nonspecific presentation results in delayed diagnosis. Frequently, this is only possible after surgery and histological examination.