A case of gastrointestinal stromal tumor of the Jejunum categorized to low risk which metastasized to omentum 2 years postoperatively

A 75-year-old man undergoing emergency laparotomy for a ruptured abdominal aortic aneurysm in January 2001 was found incidentally to have a solid tumor of the jejunum 3cm in diameter, necessitating Y graft replacement and partial jejunal resection. Microscopically, the tumor consisted of fascicles of spindle cells and stained positive for CD34 and KIT, leading to a histological diagnosis of gastrointestinal stromal tumor (GIST). Low mitotic figures (1/50 high-power field) and a low MIB-1 labeling index (3%) evidenced no malignancy. Abdominal computed tomography showed an intrabdominal mass 8cm in diameter in September 2003, so we conducted laparotomy in October 2003, resecting the main omental tumor and 2 small nearby lesions. Microscopically, the tumor morphologically resembled the previous intestinal GIST, but mitotic figures were frequent (16/50 high-power field). C-kit mutation analysis showed both tumors to have the same mutation at exon 11 of the c-kit gene (deletion of codon 564-576). The omental tumor was diagnosed as recurrent intestinal GIST. The patient is doing well 8 months postoperatively without any sign of recurrence.