[A Case of Omental Desmoid Tumor after a Small Bowel Resection for Gastrointestinal Stromal Tumor] [Article in Japanese]

Summary

Here, we report a case of omental desmoid tumor after a small bowel resection for gastrointestinal stromal tumor (GIST). A 73-year-old man underwent a partial resection of small bowel for GIST. He received adjuvant therapy with imatinib due to high risk of recurrence. After 2.5 years of treatment, a follow-up CT showed a 15mm nodule in the omentum near the splenic flexure. We considered the possibility of recurrence and imatinib failure, and laparoscopic tumor resection was performed for differential diagnosis. Immunohistochemical staining showed negative for c-kit, CD34, desmin, and S100. However, it was diagnosed as desmoid tumor because of positive b-catenin. Intra-abdominal desmoid tumor should be a differential diagnosis for a new single lesion in patients with GIST.