MKI67 and thyroid cancer, nonmedullary, 2: Also, using the same cut-off at above 5%, only 8/158 patients with FTA (including 6 Hürthle cell adenoma) had a Ki-67 index above 5%, while 19/61 patients with FTC (including 9 Hürthle cell carcinoma) exhibited a Ki-67 index higher than 5%.