MKI67 and medullary thyroid gland carcinoma: We excluded 865 tumors due to the lack of a Ki-67 index (841 adenomas and 24 carcinomas), 74 tumors since they were toxic adenomas or hyalinizing trabecular tumors, and 30 tumors since they displayed either a component of poorly differentiated carcinoma, WDT-UMP, or medullary thyroid carcinoma.