Small necrotic liver metastasis with microscopic tumor embolism in hepatic vein: a case report and review of the literature.

Small liver metastasis of rectal carcinoma is mostly solid and rarely accompanied by necrosis. Microscopic invasion of the hepatic vein is rare in colorectal metastasis. A 53-year-old man, 2 years after rectal carcinoma resection, was noted to have a 15-mm liver tumor. On imaging, it was difficult to determine if the mass was hepatic abscess, cyst, solitary necrotic nodule, or liver metastasis. The resected tumor was metastatic liver cancer, the center of which had mostly atheromatous necrosis. Also, a microscopic tumor embolism was detected in the hepatic vein around the tumor. Liver tumors that grow should be suspected of being malignant and be resected.