A Rare Case of Adenomyoepithelioma of the Breast Complicated with Cyst Diagnosed by Preoperative Core Needle Biopsy: A Case Report

INTRODUCTION: Adenomyoepithelioma (AME) of the breast is a rare benign disease in which glandular epithelial cells and myoepithelial cells proliferate to form a mass. Preoperative diagnosis is considered difficult, and diagnosis by core needle biopsy (CNB) is particularly difficult. Due to its heterogeneous features and growth patterns of the tumor cells constructing the tumor mass, this tumor, although benign in nature, is misdiagnosed as ordinary breast cancer and often treated by surgery for breast cancer. Here, a rare case of AME of the breast complicated with cysts diagnosed by preoperative CNB is reported.