[A Case of Mediastinal Lymph Node Metastasis from Liver Metastasis of Colon Cancer].

A 64-year-old woman underwent partial colectomy with partial resection ofthe retroperitoneum and D3 lymphadenectomy for descending colon cancer(tub2, pSS, ly0, v0, pN1, sH0, sP0, sM0, fStage III b). Three years and 6 months later, she underwent resection ofsegment 4 ofthe liver because ofliver metastasis. One year and 2 months later, her serum carcinoembryonic antigen level increased, and computed tomography showed an inferior mediastinal mass of 18mm in diameter. High FDG uptake by this tumor was seen on positron emission tomography-CT. Metachronous mediastinal lymph node metastasis from liver metastasis ofcolon cancer was diagnosed, and resection ofthe mediastinal lymph nodes was performed. Pathological examination revealed adenocarcinoma similar to the liver metastasis. After resection, the patient received antineoplastic agents(7 courses of modified FOLFOX6 followed by 3 courses of S-1). The patient is alive without recurrent disease 3 years and 4 months after resection of the mediastinal lymph nodes. Mediastinal lymph node metastasis from liver metastasis of colon cancer without lung metastasis is rare. Although the optimal treatment has not been determined, tumor resection may be associated with favorable outcomes.