MKI67 and neoplasm: However, previous studies have shown that ectopic thyroid can participate in thyroid hormone biosynthesis, even if the amount of thyroid hormone is insufficient.[7] Ki-67-positive tumor cells are usually associated with malignant transformation; however, no previous studies have reported on the expression of Ki-67 in ectopic thyroid tissue.[7] In our patient, the expression of Ki-67 in the ectopic goiter was relatively low.