1 Department of Pathology, Tohoku University Graduate School of Medicine, 2‑1 Seiryo‑machi, Aoba‑ku, Sendai, Miyagi, 980-8575, Japan.
2 Department of Breast Surgical Oncology, Nahanishi Clinic, Naha, Okinawa, Japan.
3 Department of Pathology, Tohoku University Hospital, Sendai, Miyagi, Japan.
4 Department of Breast and Endocrine Surgical Oncology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
5 Department of Pathology, Tohoku University Graduate School of Medicine, 2‑1 Seiryo‑machi, Aoba‑ku, Sendai, Miyagi, 980-8575, Japan. hsasano@patholo2.med.tohoku.ac.jp.
6 Department of Pathology, Tohoku University Hospital, Sendai, Miyagi, Japan. hsasano@patholo2.med.tohoku.ac.jp.