[Granular myoblastoma of the breast. Apropos of 7 cases]

7 cases of mammary granular cell tumor have been studied, and some pitfalls on frozen section diagnosis are described. Erroneous diagnosis of mammary infiltrating carcinoma leads sometimes to an useless mutilation. Over-diagnosis is possible because of: --gross features like induration and ill-defined circumscription of the tumor, --histological features and especially infiltration of the lobules and fat by granular tumor cells.