Intra-abdominal
desmoid tumors are rare and most often occur in patients with a history of
familial adenomatous polyposis, surgery, or pregnancy. We report a case of an intra-abdominal
desmoid tumor mimicking the recurrence of
gastric cancer. A 57-year-old male had undergone distal
gastrectomy for advanced
gastric cancer. Serum levels of
carcinoembryonic antigen were found to be elevated 27 months after surgery. Computed tomography revealed a 15-mm mass in the mesentery of the transverse colon. In addition, radiotracer fluorodeoxyglucose uptake of the
tumor was detected by positron emission tomography. The patient was diagnosed with
gastric cancer recurrence, and
chemotherapy consisting of
cisplatin and S-1 was commenced. After five courses of
chemotherapy, although no significant clinical response was seen, no new lesions were seen either. Thus, a curative resection of the recurrent
tumor seemed possible, which was successfully performed. Histological examination of the resected specimen revealed spindle-shaped
tumor cells with
collagen fiber progression; no
cancer cells were detected. The
tumor was diagnosed as an intra-abdominal
desmoid tumor. We report a rare case of an intra-abdominal
desmoid tumor that mimicked a recurrent
tumor arising from
gastric cancer. In patients with history of surgery for intra-abdominal
malignancies, it may be difficult to distinguish the recurrence of
malignancy from
desmoid tumors but the possibility of
desmoid tumors must be considered in the differential diagnosis.