[Perforation of Small Intestinal Gastrointestinal Stromal Tumor Required Emergency Surgery-A Case Report].

The case was a 77-year-old man. He presented with abdominal pain and melena to our hospital. Abdominal CT showed thickening of the small intestinal wall and findings of intraperitoneal free air. Suspecting peritonitis due to small intestinal tumor perforation, we performed an emergency surgery. A ruptured tumor measuring 50 mm in diameter was found in the jejunum about 15 cm from the Treitz' ligament and the partial resection of the small intestine was performed. Histopathology revealed fistulous necrosis within the tumor, and immunostaining was positive for KIT and CD34, leading to the diagnosis of jejunal GIST. He was evaluated as high risk for recurrence and was indicated for adjuvant chemotherapy. He is currently taking imatinib and is being followed up for 6 months without recurrence. Although diagnosing GIST of small intestine can be difficult, GIST of small intestine with perforation is at high risk of recurrence and rezuires adjuvant chemotherapy. Emergency surgical diagnosis should not be hesitated.