Two cases of colorectal liver metastasis with residual liver recurrence after a long recurrence-free survival period

BACKGROUND: The rate of residual liver recurrence after the resection of colorectal liver metastases is high, and most cases recur within 5 years of the initial hepatectomy. Here, we report two cases of residual liver recurrence after radical resection of colorectal liver metastases after a long recurrence-free survival period. CASE PRESENTATION: Case 1 involved a 62-year-old woman treated for ascending colon cancer in April 2011 who underwent right hepatectomy for synchronous colorectal liver metastasis in April 2012. However, in September 2021, computed tomography revealed residual recurrence in the lateral segment of the liver, and a lateral segmentectomy of the liver was performed. In Case 2, a 52-year-old man treated for cecal cancer in July 2002 underwent lateral segmentectomy of the liver for metachronous colorectal liver metastasis in October 2006. Subsequently, there was no recurrence; however, computed tomography showed residual liver recurrence in the right lobe of the liver in October 2021, and an expanded posterior hepatic segmentectomy was performed. Histopathological findings in both cases were consistent with colorectal liver metastases. CONCLUSIONS: We encountered two cases in which residual liver recurrence was observed after a long period of recurrence-free survival. Although rare, there have been a few cases of late recurrence of liver metastases after radical resection of cancer liver metastases.