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

## TL;DR

This paper presents a rare case of breast cancer in the arm and reviews existing literature to improve understanding and treatment of ectopic breast cancer.

## Contribution

The paper adds a new clinical case and provides a comprehensive literature review on ectopic breast cancer.

## Key findings

- Ectopic breast cancer is rare and often presents diagnostic and treatment challenges.
- The case highlights the possibility of a second primary cancer in ectopic breast tissue.
- Literature review emphasizes the need for improved clinical awareness and management strategies.

## 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.