[A Case of Solitary Liver Metastasis from Renal Cell Carcinoma That Was Difficult to Distinguish from Hepatocellular Carcinoma and Underwent Laparoscopic Resection].

We experienced a case of solitary liver tumor that developed after renal cancer surgery. Before the surgery, the tumor was suspected to be hepatocellular carcinoma and was subsequently diagnosed as renal cancer liver metastasis. An 81-year-old man underwent retroperitoneal laparoscopic nephrectomy for left renal cancer in January 2017. After that, the cancer had not recurred, but a follow-up CT examination 1 year after the operation revealed a 42 mm-sized tumor in the liver S6. Liver biopsy was performed for diagnosis, but in histopathological findings, the diagnosis was difficult to make. Eventually, the preoperative final diagnosis was hepatocellular carcinoma. Laparoscopic partial hepatectomy was performed in June 2018, and in the histopathological findings of the resected specimen, the final diagnosis was the liver metastasis from renal cancer. Generally, the prognosis of renal cancer with liver metastasis is poor, but if complete resection is possible, it is recommended in the Clinical Practical Guideline for Renal Cancer. In recent years, the number of minimally invasive laparoscopic surgeries for hepatectomy has increased, and its safety has also improved. Therefore, resection is diagnostic treatment for cases where, like this case, preoperative diagnosis for solitary liver tumor is difficult. Laparoscopic hepatectomy could be one of the effective treatment strategies.