[A Resected Case of Intraperitoneal Foreign Body Granuloma Mimicking Peritoneal Dissemination].

Foreign body granuloma(FBG)is a granuloma that occurs due to chronic inflammation caused by various residual foreign objects. In the field of gastrointestinal surgery, intraperitoneal foreign body granulomas(IPFBGs)are often caused by sutures materials or residual gauzes, but those caused by food residue are extremely rare. We present an IPFBG case of food residue caused by anastomotic leakage, which was difficult to be distinguished from peritoneal dissemination. The patient is a 74- year-old male. Anastomotic leakage occurred following low anterior resection for rectal cancer, peritoneal drainage and ileostomy were performed. 1.5 years after rectal resection, liver metastasis was diagnosed by CT and peritoneal dissemination was diagnosed by PET-CT. Both lesions were resected at the same time. The pathological findings were liver metastasis and FBG. It was presumed to be an FBG formed by food residue left behind after anastomotic leakage. It has reported that FBG caused by residual gauzes were shown a ring-shaped uptake by PET-CT, but that was not observed in our case. In addition, since a nodule suspected of liver metastasis was observed simultaneously, we considered no differential diagnosis other than peritoneal dissemination. IPFBG resembling peritoneal dissemination, occurred after anastomotic leakage. A food residue can cause IPFBG, it is necessary to consider IPFBG in decision making treatment strategy for peritoneal nodule.