In order to determine whether MED12 mutation is a driver genetic alteration that can contribute to the formation of these fibroepithelial tumors, we investigated the incidence of MED12 mutations in a large series of fibroepithelial tumors: PTs (n = 97, 83 primary PTs of all grades: 13 recurrences and 1 metastasis), FAs (n = 10) and fibromatosis (n = 11), a fibroblastic/myofibroblastic tumor of intermediate potential, which constitutes a differential diagnoses of fibroepithelial tumors. The gene discussed is MED12; the disease is fibromatosis.