Sarcoidosis is a multisystemic disease that may involve the breast parenchyma and can be confused with benign or malignant tumors. A recent case of sarcoidosis of the breast treated in our institution prompted us to review the world literature on the topic. From 1921 to 1997, 45 cases relating to sarcoidosis of the breast were reported; 10 of these cases were excluded from our review because of the lack of histological proof of sarcoidosis. The data were organized according to clinical presentation, diagnostic studies, treatment plan, and follow-up care. The mean age at presentation was 47 years (range 20-72 years) and all patients were female. Seven patients (20%) had a breast mass as primary presentation of sarcoidosis without any clinical evidence of systemic sarcoidosis. Thirty-one patients (89%) presented with a self-detected mass and three patients (8%) demonstrated skin dimpling and peau d'orange appearance mimicking cancer. The size of the breast lesions ranged from 0.25 to 5 cm in diameter. One patient presented with bilateral breast lesions and one with more than one lesion in the same affected breast. A single breast mass was found in the rest of the patients. Of the seven patients evaluated by mammography, only one revealed changes suspicious for malignancy. Fine-needle aspiration was used only in four cases; the results of two were compatible with sarcoidosis and two required an excisional biopsy as a result of inconclusive results. Seventeen cases reported excisional biopsy as the diagnostic procedure. In 11 patients the type of biopsy was not stated. In two cases of radical mastectomies for breast adenocarcinoma, sarcoidosis was an incidental finding, either in the remaining breast tissue or in the axillary nodes. One patient underwent a partial mastectomy revealing sarcoidosis as the definitive diagnosis. Ultrasound was used in two cases; one revealed a suspicious lesion and one was inconclusive. Although sarcoidosis of the breast constitutes a rare entity it should be considered in the differential diagnosis of breast cancer even in patients without clinical evidence of systemic sarcoidosis. These patients should undergo a biopsy to rule out malignancy because clinical findings, mammography, and ultrasound results can be misleading or inconclusive.