Whole body iodine-131 scan is a well-established imaging method for the detection of metastatic or residual tumor sites in patients with well-differentiated thyroid cancer. Many false-positive iodine-131 scan findings mimicking metastatic thyroid cancer have long been reported. The authors describe a false positive uptake in normal gallbladder on post-ablative iodine-131 scan in a patient with papillary thyroid cancer. This finding should be considered to be another possible false-positive finding on iodine-131 whole body scan.
Carcinoma, Papillary/*pathology ; False Positive Reactions ; Female ; Gallbladder/*metabolism/ultrasonography ; Humans ; Iodine Radioisotopes/diagnostic use/pharmacokinetics/therapeutic use ; Middle Aged ; Thyroid Neoplasms/*pathology ; Whole-Body Counting

The interaction between Lipiodol and cells was studied by treating Lipiodol in a human hepatocellular carcinoma cell line(Hep) and mouse fibroblast cell line (L929). Irregular, sustained radioactivity was released from both cell lines shortly after incubation in the radioiodinated Lipiodol mixed media. Lipiodol droplets were found to be firmly attached to the cells following the incubation and these cells were strongly positive for fat stains. The radioiodinated Lipiodol demonstrated the same behavior of accumulation within the cell and on the cell membrane. Although the amount of Lipiodol attached was almost equal in both of the cell lines, the final amount accumulated in the cells was larger in the Hep cells. The accumulation of Lipiodol within the cell and on the cell membrane may play a significant role for its selective targeting and its prolonged retention in the solid tumor.
Carcinoma, Hepatocellular/*pathology/therapy ; Human ; Iodine Radioisotopes/diagnostic use/therapeutic use ; Iodized Oil/pharmacokinetics/*pharmacology/therapeutic use ; Liver Neoplasms/*pathology/therapy ; Support, Non-U.S. Gov't ; Tumor Cells, Cultured/drug effects