Malignant schwannoma of the breast.

Malignant schwannoma (MS) is a tumor of the Schwann or nerve sheath cells, most frequently occurring in the lower and upper extremities, trunk and head region. We report the third known case of MS of the breast, which occurred in a 27-year-old woman. The palpable tumor, about 1.2 cm in diameter, was localized in the upper inner quadrant of the right breast. After ultrasonography, mammography and fine needle aspiration cytology, the tumor was removed surgically.