In this paper, we report the radiologic findings of cecal adenocarcinoma with caval invasion in a 60-year-old man. Caval invasion was confirmed by ultrasonographically guided fine-needle aspiration biopsy and by surgery. To our knowledge, this is the first case report demonstrating malignant caval thrombus due to colon cancer. in addition, we suggest that fine-needle aspiration biopsy may be helpful for prompt diagnosis and treatment in such a case. (c) 2007 Elsevier Inc. All rights reserved.