BACKGROUND: Lymph node metastasis of hepatocellular carcinoma is rare, and lymph nodes located on hepatic hilar and hepatoduodenal ligaments are primary targets. Metastasis to a mesocolic lymph node has not been reported previously.

CASE REPORT: A 65-year-old woman with liver cirrhosis underwent primary resection of hepatocellular carcinoma. Two and a half years later, tumor marker levels increased remarkably and imaging revealed a mesocolic mass. The tumor measured 27 mm in diameter and showed characteristic findings consistent with hepatocellular carcinoma in dynamic computed tomographic images, although the tumor was negative in fluorine-18-fluorodeoxyglucose positron emission tomographic images. A preoperative diagnosis of solitary metastasis to a mesocolic lymph node was made, and we elected to perform surgical resection, although therapeutic strategies for rare solitary extrahepatic metastasis are controversial. The tumor was located in the mesocolon nearly at the wall of the descending colon. Curative resection was performed and histopathological analysis confirmed metastatic hepatocellular carcinoma to a mesocolic lymph node. Tumor marker levels normalized immediately postoperatively. To date, the patient remains free from recurrence without adjuvant therapy.

CONCLUSIONS: This is the first known case of solitary hepatocellular carcinoma metastasis to a distant mesocolic lymph node, successfully treated. Diagnosing solitary hepatocellular carcinoma metastases to distant lymph nodes can be difficult. Although the ideal therapeutic approach has not be defined, surgical resection of solitary metastatic lymph nodes may be beneficial in carefully selected cases.

Keywords: Lymph Nodes, Mesocolon