Liver metastasis originating from colorectal cancer with macroscopic portal vein tumor thrombosis: a case report and review of the literature

INTRODUCTION Macroscopic tumor thrombi occupying the main portal branch are rarely seen in patients with liver metastasis. CASE PRESENTATION A 55-year-old Japanese man who had previously undergone surgery for adenocarcinoma of the ascending colon presented with a metastatic liver tumor accompanied by a macroscopic tumor thrombus in the right portal branch. Right lobectomy and removal of the tumor thrombus were performed, and the liver metastasis and tumor thrombus were successfully resected. Histopathological examination of the liver tumor revealed adenocarcinoma, consistent with that of the previous colon cancer, confirming that the liver tumor was a metastasis from the colon cancer. Our patient remains well without recurrence at 51 months after the liver surgery. CONCLUSION The prognosis of patients with liver metastasis accompanied by a portal vein tumor thrombus remains unknown, but, considering several previous reported cases together with our case report, a better prognosis may be expected if the tumor is successfully removed by anatomical liver resection.