TKT and adenoma: Upon immunohistochemical analysis, TKT expression was found in all tissue types, normal mammary glands (n = 4/6, 66%; IRS = 0, range 0–4), hyperplastic lesions (n = 3/3, 100%; IRS = 6, range 1–9), complex adenomas (n =5/5, 100%; IRS = 4, range 1–9), simple adenomas (n 6/6, 100%; IRS = 5, range 1–9) complex carcinomas (n = 6/6, 100%; IRS = 6, range 1–12) and simple carcinomas (n = 11/11, 100%; IRS = 1, range 1–9) (Fig. 2) (Additional file 1).