A Case of a Mesenteric Desmoid Tumor Mimicking Metachronous Hepatic Metastasis of Gastric Cancer

Abstract

A 52-year-old woman underwent laparoscopic distal gastrectomy for Stage I A gastric cancer. Eleven months later, a follow-up CT scan showed a 16-mm well-circumscribed and slightly enhanced tumor in the segment IV of the liver, which appeared to be liver metastasis. MRI studies also suggested liver metastasis, but FDG-PET scan presented no increased uptake of FDG to the tumor. Partial hepatectomy was performed with the suspected diagnosis of liver metastasis. Partial colectomy was also carried out because tumor invasion to the transverse colon was detected during surgery. However, pathological examinations did not demonstrate signet-ring cell carcinoma derived from gastric cancer and an immunostaining and a gene analysis proved that it was a mesenteric desmoid tumor. She remains well as of 24 months after the operation without recurrence. It is difficult to make the diagnosis of desmoid tumor only by imaging devices because of its rarity. Gene analysis is a key to differentiate a desmoid tumor from other malignant tumors.