Abstract
Gastrointestinal stromal tumor (GIST) is the most common mesenchymal neoplasm of the gastrointestinal tract, and its overall incidence is low. Extra-gastrointestinal stromal tumor (EGIST) is a special type of GIST which occurs at a lower frequency outside the gastrointestinal tract. We report a rare case of EGIST originated from the mesentery.
An 85-year-old man who had been treated for liver cirrhosis type C was admitted to our hospital because of acute abdominal pain, fever and progressive anemia in November 2015. He was incidentally found to have an intraabdominal tumor (3cm in diameter) 3 years before and was followed without treatment. Abdominal CT scan showed the remarkably swollen tumor (8 cm in diameter) and abnormally retained ascites. From these findings and deteriorating anemia, we estimated the tumor to be spontaneously ruptured and performed an emergency operation.
The unmovable and elastic-soft tumor was located next to the upper small intestine, and showed a deep slit accompanied with active bleeding. Only the tumor was resected, because it was not connected with any other organs including the gastrointestinal tract. The tumor was histologically composed of spindle cells with bundle-like growth, which was similar to the ordinary GIST. The tumor cells were immunohistochemically positive for KIT, CD34 and DOG1. From these histopathologial characteristics and the clinical findings, the tumor was finally diagnosed as EGIST of the mesentery origin.
