A Rare Case of Benign Granular Cell Tumor of the Breast

Introduction:Granular cell tumor is a rare benign non-encapsulated tumor mostly present in oral cavity. The breast localization is uncommon, about one to 1000 cases of breast cancer and mainly affects the premenopausal women which possible the influence of estrogen and progesterone hormonal level on progression of the tumor. This tumor isthe great emulator of the invasive ductal carcinoma of the breast clinically and radiologically, and the definite diagnosis especially in FNAC is a great challenge. GCT near always has benign clinical behavior and malignant transformation in less than 1% of cases is visualized, which requires the additional therapy other than local surgical resection. This case indicates that GCT is a rare breast neoplasm, which is benign but should be differentiate from other breast neoplasms especially invasive carcinomas.Case report: We report a rare case of GCT of the breast presenting as a single painless tumoral lesion of right breast in a 49 year-old woman, since 2 weeks ago .on mammography a single isodence mass with ill-defined borders on right lower outer quadrant without calcification and lymphadenopathy, in favor of malignancy is visualized. Cut surface of the local resected (quadrantectomy) specimen show a firm fibrotic area measuring about 1.6 cm in greater dimension ,which composed of nests and cords of polygonal cells with uniform peripherally located nuclei, inconspicuous nucleoli and prominent eosinophilic granular cytoplasms that show diffuse positive immunoreaction for S100 protein and negative reaction for cytokeratin. The 6 months follow up of the patient revealed no tumoral recurrence. Conclusion: This case indicate that GCT is a rare breast neoplasm, which although has a benign behavior ,but is a great stimulator of invasive breast carcinomas and must be kept in mind in differential diagnosis of breast granular neoplasms.

کلیدواژه ها:

granular cell tumor ، breast granular mass ، S100 positive tumors ، breast imaging