AUTHOR=Jia Shu-ni , Wang Dong , Xue Ting-ting , Zhao Zhe-xia 

TITLE=A case report of ectopic breast cancer of the left upper extremity with literature review

JOURNAL=Frontiers in Oncology

VOLUME=Volume 15 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2025.1674230

DOI=10.3389/fonc.2025.1674230

ISSN=2234-943X

ABSTRACT=Ectopic breast cancer (EBC) is a rare type of breast cancer that originates from ectopic breast tissue. This article describes a case with left breast cancer complicated by a second primary breast cancer of the left upper extremity, and summarizes the relevant literature to review the epidemiology, clinical presentation, pathologic features, imaging tests, treatment strategies, and prognosis of EBC with the aim of providing clinicians with a comprehensive reference to improve the understanding and management of this disease.