TP53 mutations were frequent in invasive carcinomas NST (73 out of 88 cases, 84.9%) and in medullary carcinomas (MED: 5 out of 5 cases, 100%) as well as in the rare subtypes (carcinoma with apocrine differentiation and metaplastic carcinoma) (4 out of 4 cases, 100%) but considerably less frequent in invasive lobular carcinomas (ILC: 4 out of 7 cases, 63.6%). The gene discussed is TP53; the disease is medullary thyroid gland carcinoma.