Granular Cell Tumor of the Breast—A Case Report—

Abstract

A 64-year-old woman was referred to our medical center with a chief complaint of a right breast mass detected during preoperative assessment of a thyroid cancer. Mammography showed a mass lesion with spiculae in the X/I region of the right breast, which was diagnosed as category 5. Ultrasonography showed a 19-mm-diameter, hypoechoic mass with an irregular surface and unclear borders in the A region of the right breast. Computed tomography showed a 20-mm-diameter nodule in the A region of the right breast, and no metastasis was observed. Magnetic resonance imaging showed an irregularly shaped mass with heterogeneous contrast within. A core-needle biopsy was performed, and a diagnosis of granular cell tumor of the breast was made. However, malignancy could not be ruled out on imaging findings, and a partial right mastectomy was performed for diagnostic and therapeutic purposes. A diagnosis of breast granular cell tumor was made by histopathological examination. Although this disease is considered to be basically benign, it is sometimes difficult to differentiate it from breast cancer because its imaging findings resemble those of breast cancer as in the present case. If malignancy cannot be ruled out, a partial mastectomy should be performed for diagnostic and therapeutic purposes.