Abstract
We report a rare case of schwannoma of the breast that occurred in a 79-year-old woman who did not have von Recklinghausen's disease. The patient complained of a growing mass and pain in her left breast for more than 6 years. An elastic-hard, smooth, movable tumor measuring 2.5cm×2.3cm was palpable in the lower inner quadrant of the left breast. Mammography showed a high-density oval lesion with a smooth outline in the lower inner area of the left breast. Ultrasonography of the breast revealed a hypo echogenic, heterogeneous well-defined mass, which led to suspicion of a fibroadenoma or phyllodes tumor. An excisional biopsy was performed, and microscopic examination revealed interlacing bundles of spindle-shaped cells and nuclear palisading. Immunohistochemical staining showed that the tumor cells were diffusely positive for S-100 protein. These findings were compatible with schwannoma. If a tumor has a clear boundary, the possibility of a schwannoma should be kept in mind when making the preoperative diagnosis.
