TG and neoplasm: Moreover, when the mean number of LNM and mean tumor size is plotted against each decile of increasing thyroglobulin (Figure 1), a sharp increase can be seen in both tumor size and LNM when the preoperative thyroglobulin level exceeds 17.9 ng/mL (the lower level for the eighth decile) and 26.8 ng/mL (the lower level for the ninth decile), respectively (Figure 1).