A Case of Descending Colon Cancer with Tumor Thrombosis in the Inferior Mesenteric Vein

Abstract

A 64-year-old woman visited a neighboring hospital with the chief complaint of abdominal pain. Since an abdominal plain computed tomography (CT) scan revealed colonic obstruction due to a descending colon tumor, she was referred to our hospital. A self-expandable metallic stent was placed in the descending colon because a colonoscopy showed a stricture encircling the whole circumference of the descending colon. Abdominal contrast-enhanced CT scan showed a tumor thrombus of the inferior mesenteric vein (IMV) and paraaortic lymph node enlargement. Therefore, she underwent left colectomy with resection of the IMV including the tumor thrombus. Operative findings showed a cord-like induration around the IMV and marked wall thickening of the proximal colon. Histopathology demonstrated the tumor thrombus to be composed of similar moderately differentiated adenocarcinoma to the primary lesion. She had been treated with 22 courses of mFOLFOX6 chemotherapy, which made the paraaortic lymph node unclear. After 44 courses of mFOLFOX6, the chemotherapy was discontinued. She remains well with no apparent signs of tumor regrowth or recurrence, as of 52 months after the surgery.

We report this rare case of descending colon cancer with tumor thrombosis in the IMV and emphasize the importance of complete resection of cancer with tumor thrombosis that can prevent the migration of cancer cells through the tumor thrombus.