Granular cell tumors of the breast are rare. The clinical presentation, the poor macroscopical delimitation and the infiltrating appearance of the tumor cells between the mammary lobules and within the adipose tissue may lead to a diagnosis of carcinoma, especially on frozen section. The authors present two cases of granular cell tumor of the breast occurring in two women aged 19 and 59 respectively. Before surgery, the diagnosis was that of a malignant tumor. In both cases, frozen section suggested the diagnosis of a granular cell tumor, which was confirmed by immunohistochemical study in one patient.