Tumoral fibrosis and lack of circumscription in granular cell tumor of the breast.

Granular cell tumors are benign neoplasms of putative Schwann cell origin that most commonly occur in the tongue. While granular cell tumors in the breast are uncommon, the occurrence of this tumor at this site warrants special consideration, since the mammographic, gross, and microscopic appearance can mimic carcinoma. We describe the case of a 61-year-old white woman with a granular cell tumor of the left breast. Our case and a review of the international literature show that desmoplasia and lack of circumscription are common features of granular cell tumor of the breast.