Adenomyoepithelial adenosis associated with breast cancer: a case report and review of the literature.

Adenomyoepithelial adenosis of the breast is an extremely rare type of adenosis. We herein present the case of a 35-year-old woman, who presented with a small painless hard lump and elastic soft induration of 5 cm in diameter in her left breast. Clinical examination and diagnostic workup were suggestive of a breast carcinoma, and a modified radical mastectomy and sentinel node biopsy were performed. Histopathological examination revealed adenomyoepithelial adenosis along with fibrocystic change and small invasive ductal carcinoma, slightly away from the adenosis. The presented case was thought to be initial-stage adenomyoepithelial adenosis and independently developing breast cancer. From a review of five reported cases of adenomyoepithelial adenosis, complete resection of the tumor and coexisting malignant disease may be recommended, owing to the tendency to develop breast cancer or malignant adenomyoepithelioma, or recurrence.