[Breast granular cell tumor]

The report of the biopsy diagnosis of the granular cell tumor with rare localization in the breast is given. Currently, the tumor is considered a neoplasm of neuroectodermal origin. Differential diagnostic criteria for the tumor are positive expression in cytoplasm of protein S-100, absence of expression of epithelial antigens, histiocytic antigens, oncoproteins, estrogens and progesterone receptors, PAS-positive reaction of intracellular granules. With ultrasound examination and mammography, a tumor always initially assessed as cancer or calcification.