ABSTRACT
The tumor embolism is defined as tumor cells within the vascular system such as pulmonary artery that is not contiguous with the other metastatic foci. The incidence of tumor embolism varies widely ranging from 3% to 26% among several studies; whereas lung cancer, prostate cancer, colorectal cancer, breast cancer, pancreas cancer are associated with high risks for tumor embolism. However thyroid cancer is rarely associated with tumor embolism. Among the rare cases, tumor embolism was reported as being mostly of follicular carcinoma or undifferentiated carcinoma, but few of papillary carcinoma. We report an unusual presentation that pulmonary tumor embolism from thyroid papillary carcinoma was diagnosed with positron emission tomography/computed tomography (CT) and chest CT.