[A Case of Resected Diffuse Large B-Cell Lymphoma Diagnosed with Liver Metastasis and Peritoneal Dissemination after Surgery for Sigmoid Colon Cancer].

We experienced a case of diffuse large B-cell lymphoma(DLBCL)that developed around the kidney about 1 year after surgery for sigmoid colon cancer. In this case, imaging findings suggestive of liver metastasis were also observed at the same time of diagnosis, therefore, diagnosis was difficult because the possibility of peritoneal dissemination could not be ruled out. The lesion was excised by surgery and a definitive diagnosis was obtained by tissue diagnosis, leading to appropriate treatment. However, one wrong step could lead to the wrong treatment policy. Therefore, when there is any doubt about the diagnosis, it is considered important to proactively perform tissue diagnosis.