Abstract

Background: Adenoid cystic carcinoma (ACC), one of the rarest neoplasia of the breast, constitutes 0.1% of all breast carcinomas. The prognosis of ACC is very good compared to other histological subtypes of breast carcinoma. Lymph node involvement and distant metastasis are very infrequent. Estrogen receptor (ER), progesterone receptor (PR) and c-erbB2 (also known as HER-2/neu) are typically negative. Case A fourty eight year-old premenauposal women was admitted to hospital with a mass on the upper outer quadrant of her left breast. Since the result of through-cut biopsy of this suspicious lesion was consistent with adenoid cystic carcinoma, modified radical mastectomy with axillary lymph node excision was applied. Pathological examination revealed a moderately differantiated adenoid cystic carcinoma of the breast. The size of invasive tumor component was 4.8 cm in its greatest dimension. Immunohistochemical analysis was consistent with triple negative phenotype ( ER,PR and c-erbB2 negative). Conclusion: ACC is a rare type of human breast carcinoma with ER, PR and c-erbB2 negative phenotype. They usually show an excellent prognosis however there is no well defined treatment options for ACC since the rarity of clinical studies in such kind of unusual histological subtypes of breast carcinomas.