Granular cell tumor is a rare, usually benign neoplasm of neural origin that may arise in virtually any site and, when situated in the breast, can mimic breast carcinoma. We describe a case of granular cell tumor of the breast in a 57-yr-old woman. Clinical evaluation, mammography, sonography and MRI suggested a carcinoma with infiltration of skin and muscle. However, the tumor did not display increased glucose metabolism on PET. Clinical findings, imaging results, histological characteristics and surgical management are discussed.