New intra-abdominal mass after operation for colorectal cancer: desmoid tumor versus peritoneal seeding

Summary

To identify differential clinical and imaging findings between intra-abdominal desmoid tumors and peritoneal seeding that developed after surgery for colorectal cancer. 8 patients (9 desmoid tumors) and 11 patients (13 peritoneal seeding masses) were enrolled in our retrospective study. In patients with a desmoid tumor, initial T-stage, initial N-stage, and level of CEA at the time of surgery for intra-abdominal tumor were lower than in patients with peritoneal seeding (p=0.027, p=0.033, and p=0.017). The desmoid tumors were frequently located in the small bowel mesentery (p=0.018) and were larger at detection (p=0.041). Round or ovoid shapes on CT images were more frequently observed with the desmoid tumors (p=0.035). Stage of colorectal cancer, CEA level, and location, size, and shape of new intra-abdominal tumors can be helpful for differentiating between intra-abdominal desmoid tumors and peritoneal seeding in patients with a history of colorectal cancer surgery.