Ascending colon cancer accompanied by tumor thrombosis in the superior mesenteric vein: A case report

INTRODUCTION: Venous tumor thrombosis occasionally accompanies renal cancer, liver cancer, and pancreatic cancer. Colorectal cancer is seldom accompanied by venous tumor thrombosis in the portal vein or the superior or inferior mesenteric veins (SMV, IMV), and little is known about its features. We report a case of ascending colon cancer with tumor thrombosis in the SMV treated with right hemicolectomy and combined resection of the SMV. PRESENTATION OF CASE: An 82-year-old man with chief complaints of loss of appetite was admitted to our hospital. He was diagnosed with ascending colon cancer accompanied with tumor thrombosis extending to the SMV. He underwent right hemicolectomy and combined resection of the tumor thrombosis and the SMV. Intestinal blood flow was evaluated by intraoperative indocyanine green (ICG) fluorography. He continued to recover well from surgery. No adjuvant chemotherapy was employed because of the patient’s advanced age and his own will. He was transferred to another hospital on postoperative day 39. Six months after surgery, abdominal CT showed multiple liver metastases. He died 8 months after surgery. DISCUSSION AND CONCLUSIONS: Radical resection of the primary tumor and surgical thrombectomy should be considered for the treatment of colorectal cancer without distant metastasis accompanied by tumor thrombosis. However, venous tumor thrombosis is representative of an aggressive cancer and that may be a strong risk factor for the development of liver metastasis. Adjuvant systematic chemotherapy in addition to complete surgical resection may be one of the treatment strategies.