Benign granular cell tumor of the breast: A misleading disease

Granular cell tumor (GCT) is a relatively rare neoplasm, and almost always benign in its prognostic behavior. Location of this tumor in the breast pre sents serious problems for differential diagnosis, both from a clinical poi nt of view and at gross pathological examination, because of its resemblanc e to carcinoma. Fine needle aspiration biopsy and intraoperative frozen sec tion examination may not be of any further help. The histogenesis of these lesions has been widely debated in the pest, but no universally accepted co nclusion has been reached. Most GCTs appear to be derived from Schwann cell s, but many different neoplastic and non-neoplastic lesions show granular c ell changes. Therefore, GCT should not be considered as a single entity but as the result of a cytoplasmic change due to still unknown metabolic alter ations that may occur in various cell types. No firm conclusions can be dra wn regarding the suspected hormonal influence on the development of breast GCT. The authors describe three typical cases of breast GCT that occurred in pat ients of different ages, and discuss the most important questions concernin g this lesion.