This glossary definition is provided for historical reference only and the information may be out of date.
stage 0 medullary thyroid carcinoma in situ
(... MED-yoo-LAYR-ee THY-royd KAR-sih-NOH-muh in SY-too)
No tumor is found in the thyroid but abnormal cells are found by screening tests. These abnormal cells may become cancer and spread into nearby normal tissue.