Abstract
The case involved a 48-year-old man who had undergone emergency operation for a hemorrhagic duodenal tumor 15 years earlier, when the tumor was located in the third part of the duodenum. It was measured 30 × 28 mm in size and was histopathlogically diagnosed as leiomyoma. However, gastrointestinal stromal tumor (GIST) of the duodenum was diagnosed, because the tumor was c-kit positive on re-examination. This time, the patient was accidentally detected to have a 9 × 6 cm cystic tumor at the mesocolon during treatment for other disease. The tumor had no continuity with the gastrointestinal tract, and there were no lymph node swelling and ascites. Mesocolonic tumor was diagnosed and surgery was performed. The resected tumor was a monolocular cystic tumor and was c-kit positive, so that epithelioid tyte GIST was diagnosed. The postoperative course was uneventful . The patient had been given oral imatinib mesylate for one year as the postoperative adjuvant chemotherapy. No recurrence has occurred, as of one year and 4 months after the operation. Since the patient had the previous history of undergoing surgery for duodenal GIST 15 years before admission which was close to the tumor treated this time, recurrence to the mesocolon was diagnosed. There are some cases of GIST which can cause late recurrence. Long-term follow-up would be mandatory even if the initial lesion is classified into the low risk neoplasms, like in our case.
