Desmoid tumor of the breast is a rare benign entity that usually is mistaken for carcinoma clinically and radiologically. We report two cases of desmoid tumor of the breast detected by mammography screening using digital breast tomosynthesis (DBT). The larger tumor was detected at both full-field digital mammography (FFDM) and DBT. The smaller desmoid tumor, however, was identified only at tomosynthesis. Mammographic and ultrasonographic findings at diagnostic work-up were consistent with carcinoma of the breast. Preoperative needle biopsies could not conclusively diagnose the lesions. Both patients underwent excisional biopsy and histopathology revealed fibromatosis of the desmoid type.