Case Report Solitary mediastinal metastasis from breast cancer after 14 years: case report Daisuke Kimura, Anri Kaneta, Chisaki Muto, Shuta Kimura, Takahiro Sasaki, Kengo Tani, Tsubasa Matsuo, Ryo Hatanaka, Takao Tsushima, Masahito Minakawa